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Integrated Rangeland Fire Management Strategy Actionable Science Plan Completion Assessment: Invasives Topic, 2015–20

Prepared in cooperation with the Bureau of Land Management and the U.S. Fish and Wildlife Service

Integrated Rangeland Fire Management Strategy Actionable Science Plan Completion Assessment: Invasives Topic, 2015–20

Open-File Report 2023–1003

U.S. Department of the Interior U.S. Geological Survey

Integrated Rangeland Fire Management Strategy Actionable Science Plan Completion Assessment: Invasives Topic, 2015–20 By Christopher R. Anthony, Matthew J. Holloran, Mark A. Ricca, Steven E. Hanser, Sue L. Phillips, Paul F. Steblein, and Lief A. Wiechman

Prepared in cooperation with Bureau of Land Management and the U.S. Fish and Wildlife Service

Open-File Report 2023–1003

U.S. Department of the Interior U.S. Geological Survey

U.S. Geological Survey, Reston, Virginia: 2023

For more information on the USGS—the Federal source for science about the Earth, its natural and living resources, natural hazards, and the environment—visit https://www.usgs.gov or call 1–888–ASK–USGS. For an overview of USGS information products, including maps, imagery, and publications, visit https://store.usgs.gov/. Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government. Although this information product, for the most part, is in the public domain, it also may contain copyrighted materials as noted in the text. Permission to reproduce copyrighted items must be secured from the copyright owner. The findings and conclusions in this report are those of the authors and do not necessarily represent the views of the Bureau of Land Management and U.S. Fish and Wildlife Service. Suggested citation: Anthony, C.R., Holloran, M.J., Ricca, M.A., Hanser, S.E., Phillips, S.L., Steblein, P.F., and Wiechman, L.A., 2023, Integrated rangeland fire management strategy actionable science plan completion assessment—Invasives topic, 2015–20: U.S. Geological Survey Open-File Report 2023–1003, 33 p., https://doi.org/​10.3133/​ofr20231003. ISSN 2331-1258 (online)

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Acknowledgments We extend particular thanks to Zachary Bowen and Anne Kinsinger, U.S. Geological Survey. Report drafts were thoughtfully reviewed by Brynne E. Lazarus, U.S. Geological Survey, and Lindy Garner, U.S. Fish and Wildlife Service. Sara Carter and Jennifer Meineke, U.S. Geological Survey, contributed to collating science products.

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Contents Acknowledgments����������������������������������������������������������������������������������������������������������������������������������������iii Abstract�����������������������������������������������������������������������������������������������������������������������������������������������������������1 Introduction����������������������������������������������������������������������������������������������������������������������������������������������������1 Methods����������������������������������������������������������������������������������������������������������������������������������������������������������7 Results and Summary�����������������������������������������������������������������������������������������������������������������������������������9 References Cited�����������������������������������������������������������������������������������������������������������������������������������������12 Glossary���������������������������������������������������������������������������������������������������������������������������������������������������������15 Appendix 1. Literature Included in Scoring Next Steps for the Invasives Topic in the Actionable Science Plan���������������������������������������������������������������������������������������������������������������16

Figures 1.

Map showing the landscape cover of sagebrush-dominated ecological systems in the western United States������������������������������������������������������������������������������������������������������3 2. Map showing large fire probability for the sagebrush biome in the western United States���������������������������������������������������������������������������������������������������������������������������������4 3. Map showing percent cover of herbaceous annuals across the sagebrush biome from 2016 to 2018���������������������������������������������������������������������������������������������������������������6

Tables 1.

Search results for the Invasives topic in the Integrated Rangeland Fire Management Strategy Actionable Science Plan establishing the terms searched, the number of unique articles resulting from that search, and general descriptions of each search����������������������������������������������������������������������������������������7 2. Criteria used to score Next Steps established for the Needs included in the Invasives topic in the Integrated Rangeland Fire Management Strategy Actionable Science Plan�������������������������������������������������������������������������������������������������������������8 3. Priority science Needs detailed under the Invasives topic in the Integrated Rangeland Fire Management Strategy Actionable Science Plan establishing the completion score, and a summary of science objectives addressed and not addressed in the scientific literature published 2015–20�����������������������������������������������������10

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Conversion Factors U.S. customary units to International System of Units Multiply

By

To obtain

Length mile (mi)

1.609

kilometer (km)

Area acre

4,047

square meter (m2)

acre

0.4047

hectare (ha)

acre

0.4047

square hectometer (hm2)

International System of Units to U.S. customary units Multiply

By

To obtain

Length kilometer (km)

0.6214

mile (mi)

square meter (m2)

0.0002471

acre

hectare (ha)

2.471

acre

square hectometer (hm2)

2.471

acre

Area

Abbreviations BLM

Bureau of Land Management

DOI

U.S. Department of the Interior

EIS

Environmental Impact Statement

IRFMS

Integrated Rangeland Fire Management Strategy

MZ

WAFWA Sage-grouse Management Zone

OFR

Open-File Report

USGS

U.S. Geological Survey

WAFWA

Western Association of Fish and Wildlife Agencies

vii

Species names Cheatgrass

Bromus tectorum

Crested wheatgrass

Agropyron cristatum

Dyer’s woad

Isatis tinctoria

Greater sage-grouse

Centrocercus urophasianus

Hoary cress

Lepidium draba

Knapweed

Centaurea spp.

Kochia

Kochia scoparia

Leafy spurge

Euphorbia esula

Mediterranean sage

Salvia aethiopis

Medusahead

Taeniatherum caput-medusae

Perennial pepperweed

Lepidium latifolium

Rush skeletonweed

Chondrilla juncea

Sagebrush

Artemisia spp.

Thistle

Cirsium spp.

Ventenata

Ventenata dubia

Yellow starthistle

Centaurea solstitialis

Integrated Rangeland Fire Management Strategy Actionable Science Plan Completion Assessment: Invasives Topic, 2015–20 By Christopher R. Anthony, Matthew J. Holloran, Mark A. Ricca, Steven E. Hanser, Sue L. Phillips, Paul F. Steblein, and Lief A. Wiechman

Abstract Loss and degradation of sagebrush rangelands due to an accelerated invasive annual grass-wildfire cycle and other stressors are significant management, conservation, and economic issues in the western United States. These sagebrush rangelands comprise a unique biome spanning 11 states, support over 350 wildlife species, and provide important ecosystem services that include stabilizing the economies of western communities. Impacts to sagebrush ecosystem processes over large areas due to the annual grass-wildfire cycle necessitated the development of a coordinated, science-based strategy for improving efforts to achieve long-term protection, conservation, and restoration of sagebrush rangelands, which was framed in 2015 under the Integrated Rangeland Fire Management Strategy (IRFMS). Central to this effort was the development of an Actionable Science Plan (Plan) that identified 37 priority science needs (Needs) for informing the actions proposed under the 5 topics (Fire, Invasives, Restoration, Sagebrush and Sage-Grouse, Climate and Weather) that were part of the collective focus of the IRFMS. Notable keys to this effort were identification of the Needs co-produced by managers and researchers, and a focus on resulting science being “actionable.” Substantial investments aimed at fulfilling the Needs identified in the Plan have been made since its release in 2016. While the state of the science has advanced considerably, the extent to which knowledge gaps remain relative to identified Needs is relatively unknown. Moreover, new Needs have likely emerged since the original strategy as results from actionable science reveal new questions and possible (yet untested) solutions. A quantifiable assessment of the progress made on the original science Needs can identify unresolved gaps and new information that can help inform prioritization of future research efforts. This report details a systematic literature review that evaluated how well peer-reviewed journal articles and formal technical reports published between January 1, 2015, and December 31, 2020, addressed six needs (hereinafter “Needs”) identified under the Invasives topic in the Plan. The topic

outlined research Needs related to the control of invasive plant species in sagebrush rangelands, with a special emphasis on invasive annual grasses. We established the level of progress towards addressing each Need following a standardized set of criteria, and developed summaries detailing how research objectives nested within Needs identified in the Plan (“Next Steps”) were either addressed well, partially addressed, or remain outstanding (that is, addressed poorly) in the literature through 2020. Our searches resulted in the inclusion of 198 science products that at least partially addressed a Need identified in the Invasives topic. The Needs that were well and partially addressed included: (1) studies of natural and anthropogenic factors influencing the distribution and spread; (2) methods of preventing, eradicating and controlling invasive plant species; (3) development of mapping techniques that provide regularly updated annual grass and fine fuel projections; and (4) assessment of the efficacy of potential cheatgrass biocontrol agents. Needs that were addressed poorly included (1) investigations of livestock grazing as a tool for managing invasive plants and (2) investigations of cheatgrass die-offs and identification and subsequent study of potential biocontrol agents associated with those die-offs. The information provided in this assessment will assist updating the Plan along with other science strategies.

Introduction Stemming the cumulative loss and degradation of sagebrush (Artemisia spp.) rangelands that comprise a unique biome across western North America represents a challenge to land managers and applied researchers in the 21st century. Functioning and viable sagebrush rangelands not only support over 350 plant and animal species of conservation concern

2   Integrated Rangeland Fire Management Strategy Actionable Science Plan Assessment: Invasives, 2015–20 (Suring and others, 2005), these landscapes are also essential for agricultural and recreational industries, and thereby play a vital role in stabilizing the economies of western communities. This is of particular importance given dramatic fluctuations resulting from the traditional dependence of these communities on energy development (Western Governors’ Association, 2017; Bureau of Land Management [BLM], 2020). Roughly 55–60 percent of sagebrush rangelands of the western United States have been lost (direct conversion) or degraded (alteration of understory vegetation or fragmentation) since European settlement (Knick and others, 2003; Miller and others, 2011). Sagebrush rangelands are currently distributed across 160 million acres of 14 western states (Remington and others, 2021; fig. 1). Arresting downward trends in sagebrush ecosystems is complex owing to multiple and often interacting stressors, including conversion to agricultural crops or non-native perennial grasses (for example, crested wheatgrass [Agropyron cristatum]), energy development, improper livestock grazing, expansion of native conifers, and other anthropogenic surface disturbing activities (for example, roads, transmission lines, exurban development; Hanser and others, 2018; Shinneman, 2019; BLM, 2020). However, altered wildfire regimes driven largely by positive feedbacks from invasive annual grasses (Miller and Eddleman, 2001; Balch and others, 2013) are perhaps the most immediate and pervasive threat to sagebrush rangelands (U.S. Fish and Wildlife Service, 2013; fig. 2). The proliferation of invasive annual grasses (for example, cheatgrass [Bromus tectorum]) and resulting increases in fire frequency and extent can ultimately result in long-term and often permanent loss of fire-intolerant species of sagebrush along with deep rooted bunchgrass and soil microbial communities that normally promote resilience to disturbance and resistance to invasion in sagebrush ecosystems (Chambers and others, 2014; Germino and others, 2016). The threat from the annual grass-wildfire cycle is greatest throughout western portions of the sagebrush biome (that is, Great Basin and Snake River Plain), where trends in proportion of larger fires and fire season length have increased since the mid-1980s and fire frequency has increased substantially compared to historic frequencies (Brooks and others, 2015). Over the next 20 years, median annual total area burned in western states supporting sagebrush is projected to increase (from a 1961–2004 baseline period; Kitzberger and others, 2017), suggesting that increasing trends in sagebrush rangeland fires are likely to continue. The increasing frequency and impact of wildfires prompted the development of an enhanced strategy for addressing rangeland fire across sagebrush-dominated regions. A significant milestone in this effort was the drafting of the Integrated Rangeland Fire Management Strategy (hereinafter

IRFMS; U.S. Department of Interior [DOI], 2015) following the issuance of Secretarial Order 3336. The IRFMS outlined coordinated, science-based approaches for improving the efficiency and efficacy of actions to better prevent and suppress rangeland fire and to improve efforts to achieve long-term protection, conservation, and restoration of the sagebrush biome. Inherent in the IRFMS was the recognition that a strong science foundation was fundamental to successful rangeland fire prevention and suppression, and to management and restoration of sagebrush rangelands and wildlife populations reliant on those rangelands. Therefore, the IRFMS further called for the development of an Actionable Science Plan (hereinafter, Plan) that identified the priority science needed to inform another generation of management strategies and tools (Integrated Rangeland Fire Management Strategy Actionable Science Plan Team, 2016). Critical elements to the Plan’s success were: (1) the collaborative identification of knowledge gaps by managers and researchers which, when filled, would break down barriers to successful implementation of management actions; and (2) a focus on the resultant priority science having “actionable” traits by: (i) immediately filling knowledge gaps; (ii) directly informing management action aimed at protecting, conserving, or restoring sagebrush ecosystems; and (iii) facilitating funding mechanisms for effective research and communication of results to management audiences. Accordingly, needed science was identified by considering planning and prioritization efforts conducted in the previous 5 years by Federal and State agencies. The resulting comprehensive list was prioritized with engagement of the broader research and management communities. The 37 highest-priority science needs (hereinafter, Needs) identified through these efforts were then organized under five topics outlined in the IRFMS: (1) Fire, (2) Invasives (plant species), (3) Restoration, (4) Sagebrush and Sage-Grouse, and (5) Climate and Weather. A multi-disciplinary team of experts developed narratives describing these highest-priority Needs and outlined a series of research objectives (hereinafter, Next Steps) to help guide the development of new knowledge, syntheses, and decision-support tools for addressing each Need.

Introduction  3

Figure 1. Map showing the landscape cover of sagebrush-dominated (Artemisia ssp.) ecological systems in the western United States. Figure is taken from Chambers and others (2017, fig. 28).

4   Integrated Rangeland Fire Management Strategy Actionable Science Plan Assessment: Invasives, 2015–20

Figure 2. Map showing large fire probability for the sagebrush biome in the western United States. Figure taken from Chambers and others (2017, fig. 34).

Introduction  5 Conservation strategies depend on the consideration and application of the best available science, and ongoing efforts to address gaps in that scientific knowledge, to achieve management success. While the state of the science has ostensibly advanced owing to substantial research investments since the Plan’s release in 2016, the extent to which knowledge gaps remain relative to identified Needs is largely unknown. Several annotated bibliographies have made strides towards making results from research efforts in the sagebrush biome available and tractable for management audiences (for example, Carter and others, 2020; Poor and others, 2021). However, many knowledge gaps likely remain, and an assessment of progress made on achieving previously identified priorities is needed to help focus the next prioritization on unresolved gaps in the science and new science needs that have arisen since development of the original strategy. A quantifiable and targeted assessment of progress made towards meeting the original Needs under the Plan’s five topics can help identify unresolved gaps and prioritize future actionable research efforts for new questions and possible (yet untested) solutions. The Invasives topic in the Plan identified six Needs focused on understanding components of exotic plant species invasions and approaches to manage them, with an emphasis on invasive annual grasses, especially cheatgrass (fig. 3). The priorities identified across the six Needs broadly encompassed: (1) determining the factors that influence invasive plant species distributions and spread; (2) improving prevention, eradication, and control measures for invasive plant species;

(3) developing high-resolution maps and monitoring tools to inform early detection and invasive plant control efforts; (4) assessing the effectiveness of targeted livestock grazing to reduce invasive annual grasses; and (5) investigating potential biocontrol agents for cheatgrass and developing approaches for improving the production and delivery of successful biocontrol agents. This report details a literature review that quantified how well peer-reviewed journal articles and formal technical reports published between January 1, 2015, and December 31, 2020, addressed six Needs identified under the Invasives topic in the Plan. Five years was considered an adequate time period for implementation of science projects that coincided with or were inspired by the Plan and, as such, a suitably defined interval for completing this assessment and updating priority science and management needs. Our objective was to comprehensively summarize the scientific literature generated since the release of the Plan. Leveraging advances in bibliographic search-engine tools, we developed a quantitative “scorecard” to assess progress towards addressing each Need following a standardized set of criteria. The scorecard informed summaries detailing how Next Steps were addressed in the literature as well as those that remain unresolved. The summaries are intended to provide information for stakeholder-driven efforts aimed at identifying the next set of science needs in a forthcoming updated version of the Plan.

6   Integrated Rangeland Fire Management Strategy Actionable Science Plan Assessment: Invasives, 2015–20

Figure 3. Map showing percent cover of herbaceous annuals across the sagebrush biome from 2016 to 2018 (Western Governors’ Association Toolkit, 2020).

Methods  7

Methods We organized literature reviews on the five overarching topics included in the Plan (that is, [1] Fire, [2] Invasives (plant species), [3] Restoration, [4] Sagebrush and SageGrouse, and [5] Climate and Weather). For the Invasives topic, we initially reviewed the invasive plant species literature that was included in broad searches for literature pertaining to cheatgrass, medusahead (Taeniatherum caput-medusae) and ventenata (Ventenata dubia) provided by Poor and others (2021). We then used USGS BiblioSearch (Kleist and Enns, 2022) to search the reference databases Web of Science and Scopus using broad search terms (for example, cheatgrass) then search terms specific to the Next Steps (for example, rush skeletonweed AND sagebrush) to capture the science products that may have been excluded by the broad search terms

(table 1). We examined all papers included in the resulting lists of literature for relevance to the science Needs identified in the Invasives topic. Products searched included published literature and peer-reviewed Federal research reports (for example, Open-File Reports released by the U.S. Geological Survey [USGS]). Data releases, popular articles, “gray” literature, and other lower-tier publications were not included in search results (Kleist and Enns, 2022), although some of these types of literature (for example, data releases) were summarized in the annotated bibliographies we accessed (for example, Carter and others, 2020; Poor and others, 2021) and included in our review when pertinent. In situations where a research report was later published in the peer-reviewed literature, we only considered the published manuscript; in situations where the research report included pertinent information not included in the manuscript, we considered both.

Table 1. Search results for the Invasives topic in the Integrated Rangeland Fire Management Strategy Actionable Science Plan establishing the terms searched, the number of unique articles resulting from that search (Unique Results), and general descriptions of each search (Comment). [For more information on the individual Needs, please see Needs 1–6 described in the report. Search terms: We used a search algorithm (Kleist and Enns, 2022) during early stages of tool development, and at that time the entire term between the word AND in the search terms was not searched (for example, “invasive” and “species” searched, not “invasive species”). This resulted in broader and more inclusive lists of literature. Unique results: The number of papers associated with each search term represent the number of unique papers resulting from that search but are not necessarily unique to the search (for example, the same paper could be included in the count of both the “cheatgrass” and “invasive species AND sagebrush” searches).]

Search terms

Unique results

Comment

cheatgrass OR cheat grass OR downy brome OR Bromus tectorum

345

2015–20; broad search term

medusahead OR medusa head

115

2015–20; broad search term

ventenata OR Ventenata dubia

27

2015–20; broad search terms captured in Poor and others (2021)

invasive species AND sagebrush1

88

2015–20; broad search term

soil mapping AND sagebrush

12

2015–20; Need 1; targeted search term

leafy spurge AND sagebrush1

0

2015–20; Needs 1–3; targeted search term

knapweed AND sagebrush1

1

2015–20; Needs 1–3; targeted search term

thistle AND sagebrush1

2

2015–20; Needs 1–3; targeted search term

kochia AND sagebrush1

7

2015–20; Needs 1–3; targeted search term

mediterranean sage AND sagebrush1

0

2015–20; Needs 1–3; targeted search term

hoary cress AND sagebrush1

0

2015–20; Needs 1–3; targeted search term

perennial pepperweed AND sagebrush1

0

2015–20; Needs 1–3; targeted search term

rush skeletonweed AND sagebrush1

0

2015–20; Needs 1–3; targeted search term

yellow starthistle AND sagebrush1

0

2015–20; Needs 1–3; targeted search term

dyer’s woad AND sagebrush1

0

2015–20; Needs 1–3; targeted search term

feral horses AND sagebrush

6

2015–20; Need 4; targeted search term

livestock grazing AND fuel AND sagebrush

3

2015–20; Need 4; targeted search term

livestock grazing AND invasive grass

48

2015–20; Need 4; targeted search term

livestock grazing AND sagebrush treatment

10

2015–20; Need 4; targeted search term

targeted livestock grazing AND economics AND sagebrush

0

2015–20; Need 4; targeted search term

biocontrol AND cheatgrass

6

2015–20; Needs 5 and 6; targeted search term

1The search algorithm (Kleist and Enns, 2022) used was updated to include the entire search term between the word AND for these searches.

8   Integrated Rangeland Fire Management Strategy Actionable Science Plan Assessment: Invasives, 2015–20 We established how well Needs (that is, priority science required to inform the next generation of management strategies) listed in the Plan were addressed in the literature by independently “scoring” each Need from Next Steps (that is, science objectives required to address a Need) associated with the Invasives topic. Papers that were relevant to a Next Step were considered when scoring that Next Step. Our review approach initially focused on summaries provided in Poor and others (2021), or a paper’s abstract. If this information suggested that the research was related to a Next Step, we focused our in-depth examination on research objectives, study area descriptions, and data collection and analysis methods. Because the objective of this project was to assess if Next Steps had been addressed, we did not systematically summarize results, although we considered results when necessary to determine if the research addressed a Next Step. A given paper could be relevant to more than one Next Step in a Need, more than one Need, and more than one topic. Each Next Step was scored based on the relevant literature following a set of criteria (table 2). Scores were scaled from 0.00 to 1.00 with 0.00 indicating that the Next Step had not been considered (that is, no papers were reviewed that considered the objective(s) detailed in the Next Step) and 1.00 indicating that the Next Step had been considered at the full spatial extent of the issue being investigated. Scores progressively decreased as the applicability of the research associated with a Next Step became more regional or localized. The scale of inference for Next Steps that were pertinent to the entire sagebrush biome was based on Western Association of Fish and Wildlife Agencies Management Zones (WAFWA; MZ) for sage-grouse (Stiver and others, 2006; fig. 1). If studies were distributed in one MZ or less than or equal to three adjoining MZs, the scale of inference was considered local or regional, respectively. “NA” was assigned when a Next Step could not be evaluated with the literature review approach we used (for example, data releases, online tools), and that Next Step was not scored. A Next Step that could be addressed adequately following our approach but that had no relevant literature

identified was scored 0.00 (not NA) and included in the scoring of the Need. Each Need was scored as the proportion of the Next Steps associated with that Need that received a score greater than or equal to (≥) 0.75 (table 2). We categorized each Need based on the scores as addressed well by the literature (scores ≥0.67; that is, a majority of the Next Steps associated with that Need received a score of 0.75 or greater), partially addressed by the literature (scores 0.50–0.66) or addressed poorly by the literature (scores less than or equal to [≤] 0.49). We did not distinguish between Next Steps identified in the Plan as accomplishable within 3 years (short-term) and longer than 3 years (long-term) because 5 years had elapsed between plan formulation and this report. For each Need, we developed a summary of the Next Steps. Summaries were organized by Need and describe Next Steps or portions of a Next Step that had been “Addressed” and those that had not (that is, “Outstanding”) based on the details in the Next Steps rather than each Need in entirety. As such, descriptions of the research related to a given Next Step could be included in both the summaries of the science that had been Addressed as well as what remains Outstanding for a Need. These summaries provide details of how well specific science objectives established in the Plan were addressed and are important for evaluating the scores and informing the next set of science needs in the updated Plan. Research relevant to the science Needs identified in the Plan continues to be conducted and published. However, because we are not privy to all the research being conducted throughout the sagebrush biome, and we did not want to bias assessments to internal research efforts, products released after 2020 and interim updates of ongoing research were not discussed in this report. As such, the completion scores provided in this assessment are snapshots, and should be augmented with knowledge of newly published and ongoing research programs using the search and scoring methods described in this report when updating the Plan.

Table 2. Criteria used to score Next Steps established for the Needs included in the Invasives topic in the Integrated Rangeland Fire Management Strategy Actionable Science Plan. Scoring description

Score

Next Step addressed across the sagebrush range, or at the full spatial extent of the issue being investigated

1.00

Next Step addressed and was scale independent (for example, literature summaries)

1.00

Next Step partially addressed across the sagebrush range, or at the full spatial extent of the issue being investigated

0.75

Next Step partially addressed and was scale independent

0.75

Next Step fully addressed at the local or regional level

0.50

Next Step partially addressed at the local or regional level

0.25

Next Step not addressed

0.00

Next Step could not be assessed through literature review approach used (for example, development of databases) 1Next Step not included in scoring of Need

NA1

Results and Summary   9

Results and Summary We reviewed 670 products that were identified by the literature searches conducted for the Invasives topic (table 1). Of those, 198 unique products were directly related to at least one of the six Needs. Most (84 percent) of the 44 Next Steps included in the topic had greater than or equal to one published product that at least partially addressed the science objective(s) detailed by that Next Step. Seven Next Steps could not be effectively assessed with the evaluation approach we used and were not scored (“NA”; table 2). The seven Next Steps that could be effectively assessed but had no related products (that is, were scored as 0.00 not as NA) included: (1) a meta-analysis of literature addressing the distribution, spread, and environmental associations of cheatgrass (although a meta-analysis of changes in plant community structure in response to exotic vegetation not including cheatgrass has been conducted; Need 1); (2) a synthesis of the effectiveness and economic efficiencies of using livestock to create and maintain fire breaks and for targeted fuel treatments (two Next Steps under Need 4); (3) study designs developed to assess the impacts to non-target plant, animal and microbial communities of biocontrol agents being considered for broad-scale application (two Next Steps under Need 5); and (4) approaches to measuring pathogen loads in soils and identification of locations for conducting study trials on cheatgrass die-offs (two Next Steps under Need 6). Table 3 provides the completion scores for each Need and summaries of the literature evaluated for Next Steps. Literature citations are provided in Appendix 1, organized by Next Step. The Needs that were addressed well (scores ≥0.67) included the development of biome-wide mapping and inventory techniques that can provide regularly updated, spatiallyexplicit invasive annual grass and fine fuel projections from remotely sensed data (Need 3). Further, although the Next Steps associated with improving production and delivery of cheatgrass biocontrol agents (Need 5) were not expressly addressed, the lack of replication of Kennedy's (2018) results across the sagebrush range indicated low efficacy of currently formulated agents. Hence, several of these Next Steps appear no longer relevant and Need 5 can be considered to have been addressed well. Two Needs that were partially addressed by the literature (scores 0.50–0.66), included investigations of the natural and anthropogenic factors influencing the distribution and spread of invasive plants (Need 1); and the identification of improved methods of prevention, eradication, and control for invasive plant species (Need 2). Numerous local and regional scale studies have investigated relationships among various biotic and abiotic ecosystem characteristics and invasive plant

distributions. Additionally, sagebrush ecosystem responses to a suite of invasive annual grass management measures throughout the sagebrush biome have been investigated. The Needs that were addressed poorly (scores <0.49) were studies which examined the effectiveness of targeted livestock grazing as a management tool for invasive annual grasses and evaluations of impacts of these activities on native plants (Need 4); and investigations of cheatgrass die-offs and identification and subsequent study of potential biocontrol agents associated with those die-offs (Need 6). Although several local scale studies have investigated different aspects of livestock grazing on fine fuel loads, assessments of the effectiveness of using livestock to maintain fuel load objectives and create fuel discontinuity (for example, fuel breaks) require spatial replication across the sagebrush biome. Further, several local scale or greenhouse studies have investigated the effects of different soil pathogens on cheatgrass, but links between pathogen soil loading, invasive annual grass survival, and the potential for broad applicability of these pathogens as biocontrol agents or management tools have not been made. There were several Next Steps identified under the Invasives topic that were addressed poorly, even when the overall Need was well or partially addressed. There remains a paucity of studies related to natural and anthropogenic processes influencing invasive plant species other than invasive annual grasses (for example, leafy spurge [Euphorbia esula], knapweed [Centaurea spp.], kochia [Kochia scoparia]) across the range of these other species in the sagebrush biome (Needs 1 and 2). Assessments of the effectiveness of potential control measures for these other invasive species are also lacking. Risk assessments for establishing cost-benefit estimates of different invasive annual grass management measures have not been conducted (Need 2). Strategies for minimizing or interrupting major vectors (that is, seed dispersal mechanisms) contributing to the spread of invasive annual grasses are needed (Need 2). Investigations into the effects of biocontrol agents on soil microbial communities, best management practices for the use of biocontrols, and delivery mechanisms of bacteria applications over large areas are lacking (Need 5). The completion scores and summaries in this report provide the basis to identify new actionable science priorities that are needed to address the issues continuing to drive the loss, degradation, restoration, and fragmentation of sagebrush habitats in the western United States. The resulting information can directly inform an update to the Plan, as well as other highly relevant science planning documents including, but not limited to: Parts 1 and 2 of the Science Framework (Chambers and others, 2017; Crist and others, 2019), the WAFWA Sagebrush Conservation Strategy (Remington and others, 2021), and online science portals for managers in various stages of development. Because actionable science production continues to move forward quickly, Needs and Next Steps likely to be addressed by science released after 2020 will require consideration in Plan updates.

10   Integrated Rangeland Fire Management Strategy Actionable Science Plan Assessment: Invasives, 2015–20 Table 3. Priority science Needs detailed under the Invasives topic in the Integrated Rangeland Fire Management Strategy Actionable Science Plan establishing the completion score (Score), and a summary of science objectives addressed and not addressed (Outstanding) in the scientific literature published 2015–20. Need

Score

Summary of 2015–20 literature

Need 1: Improve understanding of the natural and anthropogenic factors that influence invasive plant species distributions, including invasion history, surface disturbance, habitat condition, and fire history, and determine whether those factors can help identify tradeoffs among alternative management approaches.

0.78

Addressed: Substantial numbers of local and regional scale studies distributed throughout the sagebrush biome have investigated ecosystem responses to different invasive annual grass management options and post-disturbance habitat recovery rates have been studied predominantly in the context of investigating sagebrush habitat restoration efforts (see also Restoration topic Needs 5, 6, 7, 8, and 9 summaries). Literature reviews regarding the influence of weather and climate on the spread of cheatgrass have been completed, and multiple local scale studies have investigated relationships between weather, climate, and other biotic and abiotic conditions on the spread of invasive annual grasses including cheatgrass and medusahead (see also Invasives topic Need 2 summary). The distribution and percent cover of cheatgrass has been mapped at local, regional, and range-wide scales, and several automated tools have been developed to estimate cheatgrass cover through time to characterize seasonal and annual variation across the sagebrush biome. Probability of occurrence modeling (climate suitability models) for 15 invasive plant species has been conducted range wide. Soil properties have been mapped at local, regional, and range-wide scales and these maps have been used to inform invasive annual grass decision support tools. Outstanding: Studies linking biotic and abiotic variables with the distribution and invasion of medusahead and ventenata have not been replicated across the range of these two species. A meta-analysis investigating the distribution, spread, environmental associations and management of cheatgrass has not been completed. Literature reviews for nonnative annual grasses other than cheatgrass are lacking. Maps and remote sensing monitoring tools for invasive annual grasses other than cheatgrass (for example, medusahead and ventenata) are lacking across much of these species' ranges. Range-wide soil mapping products lack local specificity limiting management relevance in certain areas of the sagebrush biome.

Need 2: Improve measures for prevention, eradication, and control of invasive plant species, and use risk assessments to weigh potential benefits and deleterious effects of different measures on native plant species.

0.40

Addressed: A substantial number of predominantly local-scale studies distributed throughout the sagebrush biome have investigated relationships among various biotic and abiotic ecosystem characteristics and invasive annual grass response to vegetation management. The ecology of invasive annual grass seed dispersal in the context of treating invaded sites has been investigated at local scales. Frameworks for managing invasive annual grasses through the identification of areas resistant to invasion for targeting conservation and restoration actions have been developed at local and range-wide scales. Outstanding: Risk assessments for generating cost-benefit estimates of different invasive annual grass management measures have not been conducted. Guidelines for evaluating causes of cheatgrass and medusahead invasion and expansion have not been developed. Strategies to minimize or interrupt major vectors contributing to the dispersal of invasive annual grasses are needed. Investigations of the ecology of invasive annual grass seed dispersal to inform strategies for preventing invasion are limited.

Results and Summary   11 Table 3. Priority science Needs detailed under the Invasives topic in the Integrated Rangeland Fire Management Strategy Actionable Science Plan establishing the completion score (Score), and a summary of science objectives addressed and not addressed (Outstanding) in the scientific literature published 2015–20.—Continued Need

Score

Summary of 2015–20 literature

Need 3: Conduct invasive plant inventory, including spatial data on infestations and current range maps, to improve the ability for managers to prioritize actions to prevent and control nonnative plant populations before they become established and spread.

1.00

Addressed: Spatially-explicit invasive annual grass datasets, mapping products, and early detection monitoring approaches that rely on remotely sensed data have been developed at local, regional and range-wide scales across the sagebrush biome. Fine fuels projections for informing wildfire risk have been developed in relation to climatic conditions and used to predict future cheatgrass and other invasive annual grass distributions range wide (see also Invasives topic Need 1 and Fire topic Need 3 summaries). Outstanding: Although this Need is scored as being addressed, note that the level of completion of the initiation of standardized field collection protocols for informing early detection of invasive annual grasses, and the development of a centralized clearinghouse of invasive annual grass occurrence data (two objectives associated with this Need) are unknown because these types of products or efforts would not be identified consistently by the literature search approach we used. These Next Steps were not included in the scoring of this Need.

Need 4: Assess effectiveness of targeted grazing with livestock to reduce nonnative annual grasses and understand the impact on native plants in the sagebrush ecosystem.

0.27

Addressed: Local scale studies investigating different aspects of livestock grazing on fine fuel loads and flammability, and fire behavior have been completed. A large number of local, regional and range-wide studies investigating the restoration of sagebrush habitats dominated by invasive annual grasses, including studies that assessed the seeding of a variety of native and introduced vegetative species, have been conducted throughout the sagebrush biome (see also Restoration topic Needs 2, 6, and 8 summaries). Several local, regional and range-wide studies have investigated long-term, interactive responses of sagebrush habitats to restoration options combined with livestock grazing pre- and post-treatment (see also Fire topic Need 7 summary). Local scale fire behavior fuel models incorporating precipitation variables and dynamic fuel estimates have been developed. Several local scale studies investigating relationships between livestock grazing, herbaceous cover and sage-grouse habitat suitability have been conducted throughout the sagebrush biome (see also Sagebrush and Sage-grouse topic Need 2 summary). Relationships between livestock grazing and invasive annual grass occurrence and probabilities of invasion have been investigated by local scale studies distributed throughout the sagebrush biome. A limited number of feeding trial studies investigating approaches to promote high herbaceous biomass utilization of invasive annual grasses by livestock have been conducted. Literature pertaining to the ecological effects of feral horses on rangelands has been summarized. Outstanding: Assessments of the effectiveness of using livestock to manage fine fuel loads, including evaluations of the rate, frequency, and timing of grazing events required to maintain fuel load objectives, require spatial replication across the sagebrush biome. Using livestock to create fire breaks has not been investigated. Investigations of chemical and mechanical fuels treatments in combination with livestock grazing are lacking. Economic studies of targeted livestock grazing as a fuel treatment have not been conducted. Studies explicitly linking livestock grazing to manage fuel loads and habitat suitability for sage-grouse and other sagebrush associated wildlife are limited. Studies investigating approaches to managing livestock to ameliorate the spread of invasive annual grasses are lacking. Specific guidance for implementing fuels management programs using livestock have not been published. The effects of feral horses on the proliferation of invasive annual grasses requires further study across the sagebrush biome.

12   Integrated Rangeland Fire Management Strategy Actionable Science Plan Assessment: Invasives, 2015–20 Table 3. Priority science Needs detailed under the Invasives topic in the Integrated Rangeland Fire Management Strategy Actionable Science Plan establishing the completion score (Score), and a summary of science objectives addressed and not addressed (Outstanding) in the scientific literature published 2015–20.—Continued Need

Score

Summary of 2015–20 literature

Need 5: Conduct detailed optimization studies on production and delivery systems of biocontrol agents, followed by evaluation in scaled-up field inoculation trials.

0.60

Addressed: The effectiveness of weed-suppressive bacteria treatments at reducing cheatgrass has been assessed through a series of spatially-replicated studies attempting to replicate the results of successful suppression of invasive annual grasses by biocontrol agents published by Kennedy (2018). These studies investigating the effectiveness of biocontrol agents have been summarized in a special issue of Rangeland Ecology and Management (vol. 73; 2020). Outstanding: Studies assessing the impacts to non-target plant, animal and soil microbial communities of biocontrol agent use across broad spatial scales have not been published. However, the lack of replication of Kennedy's (2018) results across the sagebrush range indicated low efficacy of currently formulated agents, and several of the Next Steps not addressed in Need 5 (and included in the scoring) appear no longer relevant. Functionally, Need 5 can be considered to have been addressed.

Need 6: Investigate cheatgrass die-off and potential biocontrols for cheatgrass to provide effective tools for site preparation.

0.29

Addressed: Numerous local scale or greenhouse studies have been conducted investigating the effects on cheatgrass of several different potential soil pathogens. Local and regional studies presenting cheatgrass die-off geospatial mapping approaches have been conducted in the Great Basin. Several experimental local scale studies have investigated cheatgrass seed survival in combination with manipulated environmental conditions in response to different soil pathogens. Local scale studies have been conducted investigating seedling survival and productivity of restoration treatments using native seeds (perennial grasses, forbs, and shrubs) in cheatgrass die-offs. Outstanding: The link between pathogen soil loading, invasive annual grass survival, and using pathogens as a management approach to prepare for restoration seeding have not been investigated. Predictive spatial models of cheatgrass die-offs need to be spatially replicated across the Great Basin. Spatial replication of studies assessing restoration success of seeding cheatgrass die-off areas and non-target species response to cheatgrass pathogens is lacking. Molecular-genetic techniques for measuring pathogen loads in soils and approaches to predicting seedbed pathogen loading for informing study designs have not been published.

References Cited Balch, J.K., Bradley, B.A., D’Antonio, C.M., and GómezDans, J., 2013, Introduced annual grass increases regional fire activity across the arid western USA (1980–2009): Global Change Biology, v. 19, no. 1, p. 173–183. Brooks, M.L., D’Antonio, C.M., Richardson, D.M., Grace, J.B., Keeley, J.E., DiTomaso, J.M., Hobbs, R.J., Pellant, M., and Pyke, D., 2004, Effects of invasive alien plants on fire regimes: Bioscience, v. 54, no. 7, p. 677–688. Brooks, M.L., Matchett, J.R., Shinneman, D.J., and Coates, P.S., 2015, Fire patterns in the range of greater sagegrouse, 1984–2013—Implications for conservation and management: U.S. Geological Survey Open-File Report 2015–1167, 66 p. [Also available at https://doi.org/​10.3133/​ ofr20151167.]

Bureau of Land Management (BLM), 2020, Final programmatic EIS for fuels reduction and rangeland restoration in the Great Basin: BLM Idaho State Office, Boise, Idaho, 153 p. [Also available at https:​//eplannin​g.blm.gov/​eplanning-​ui/​ project/​122968/​570.] Carter, S.K., Arkle, R.S., Bencin, H.L., Harms, B.R., Manier, D.J., Johnston, A.N., Phillips, S.L., Hanser, S.E., and Bowen, Z.H., 2020, Annotated bibliography of scientific research on greater sage-grouse published from 2015 to 2019: U.S. Geological Survey Open-File Report 2020–1103, 264 p. [Also available at https://doi.org/​ 10.3133/​ofr20201103.]

References Cited  13 Chambers, J.C., Beck, J.L., Bradford, J.B., Bybee, J., Campbell, S., Carlson, J., Christiansen, T.J., Clause, K.J., Collins, G., Crist, M.R., Dinkins, J.B., Doherty, K.E., Edwards, F., Espinosa, S., Griffin, K.A., Griffin, P., Haas, J.R., Hanser, S.E., Havlina, D.W., Henke, K.F., Hennig, J.D., Joyce, L.A., Kilkenny, F.M., Kulpa, S.M., Kurth, L.L., Maestas, J.D., Manning, M., Mayer, K.E., Mealor, B.A., McCarthy, C., Pellant, M., Perea, M.A., Prentice, K.L., Pyke, D.A., Wiechman, L.A., and Wuenschel, A., 2017, Science framework for conservation and restoration of the sagebrush biome—Linking the Department of the Interior’s Integrated Rangeland Fire Management Strategy to long-term strategic conservation actions—Part 1. Science basis and applications: Fort Collins, Colorado, U.S. Forest Service, Rocky Mountain Research Station, General Technical Report RMRS-GTR-360, 213 p. [Also available at http​s://www.fs​.usda.gov/​treesearch/​pubs/​53983.] Chambers, J.C., Bradley, B.A., Brown, C.S., D’Antonio, C., Germino, M.J., Grace, J.B., Hardegree, S.P., Miller, R.F., and Pyke, D.A., 2014, Resilience to stress and disturbance, and resistance to Bromus tectorum L. invasion in cold desert shrublands of Western North America: New York, Ecosystems, v. 17, no. 2, p. 360–375. Crist, M.R., Chambers, J.C., Phillips, S.L., Prentice, K.L., and Wiechman, L.A., eds., 2019, Science framework for conservation and restoration of the sagebrush biome: Linking the Department of the Interior's Integrated Rangeland Fire Management Strategy to long-term strategic conservation actions—Part 2. Management applications: Fort Collins, Colorado, U.S. Forest Service, Rocky Mountain Research Station, Gen. Tech. Rep. RMRS-GTR-389, 237 p. [Also available at https://doi.org/​10.2737/​RMRS-​GTR-​389.] Germino, M.J., Belnap, J., Stark, J.M., Allen, E.B., and Rau, B.M., 2016, Ecosystem impacts of exotic annual invaders in the Genus Bromus, in Germino, M.J., Chambers, J.C., and Brown, C.S., eds., Exotic brome-grasses in arid and semiarid ecosystems of the Western U.S.: Springer Series on Environmental Management, Switzerland, Springer International Publishing, p. 61–95. [Also available at https://doi.org/​10.1007/​978-​3-​319-​24930-​8_​1.] Hanser, S.E., Deibert, P.A., Tull, J.C., Carr, N.B., Aldridge, C.L., Bargsten, T.C., Christiansen, T.J., Coates, P.S., Crist, M.R., Doherty, K.E., Ellsworth, E.A., Foster, L.J., Herren, V.A., Miller, K.H., Moser, A., Naeve, R.M., Prentice, K.L., Remington, T.E., Ricca, M.A., Shinneman, D.J., Truex, R.L., Wiechman, L.A., Wilson, D.C., and Bowen, Z.H., 2018, Greater sage-grouse science (2015–17)—Synthesis and potential management implications: U.S. Geological Survey Open-File Report 2018–1017, 46 p. [Also available at https://doi.org/​10.3133/​ofr20181017.]

Integrated Rangeland Fire Management Strategy Actionable Science Plan Team, 2016, The Integrated Rangeland Fire Management Strategy Actionable Science Plan: Washington, D.C., U.S. Department of the Interior, 128 p. [Also available at https​://pubs.er​.usgs.gov/​publication/​ 70178487.] Kennedy, A.C., 2018, Selective soil bacteria to manage downy brome, jointed goatgrass, and medusahead and do no harm to other biota: Biological Control, v. 123, p. 18–27. Kitzberger, T., Falk, D.A., Westerling, A.L., and Swetnam, T.W., 2017, Direct and indirect climate controls predict heterogeneous early mid-21st century wildfire burned area across western and boreal North America: PLoS ONE, v. 12, no. 12, 24 p. [Also available at https://doi.org/​10.1371/​ journal. pone.0188486.] Kleist, N.J., and Enns, K.D., 2022, USGS BiblioSearch—A python tool to facilitate searching, cleaning, and compiling of literature citations from across multiple databases, Version 1.0.0: U.S. Geological Survey software release. [Also available at https://doi.org/​10.5066/​P9EW8BO5.] Knick, S.T., Dobkin, D.S., Rotenberry, J.T., Schroeder, M.A., Vander Haegen, W.M., and Van Riper, C., III, 2003, Teetering on the edge or too late?—Conservation and research issues for avifauna of sagebrush habitats: The Condor, v. 105, no. 4, p. 611–634. Miller, R.F., and Eddleman, L.L., 2001, Spatial and temporal changes of sage-grouse habitat in the sagebrush biome: Oregon State University Agricultural Experiment Station Technical Bulletin, no. 151, 39 p. [Also available at ht​ tps://cata​log.extens​ion.oregon​state.edu/​tb151.] Miller, R.F., Knick, S.T., Pyke, D.A., Meinke, C.W., Hanser, S.E., Wisdom, M.J., and Hild, A.L., 2011, Characteristics of sagebrush habitats and limitations to long-term conservation, in Knick, S.T., and Connelly, J.W., eds., Greater sagegrouse—Ecology and conservation of a landscape species and its habitats: Berkeley, University of California Press, Studies in Avian Biology, no. 38, p. 145–184. Poor, E.E., Kleist, N.J., Bencin, H.L., Foster, A.C., and Carter, S.K., 2021, Annotated bibliography of scientific research on Ventenata dubia published from 2010 to 2020: U.S. Geological Survey Open-File Report 2021–1031, 26 p. [Also available at https://doi.org/​10.3133/​ofr20211031.] Remington, T.E., Deibert, P.A., Hanser, S.E., Davis, D.M., Robb, L.A., and Welty, J.L., 2021, Sagebrush conservation strategy—Challenges to sagebrush conservation: U.S. Geological Survey Open-File Report 2020–1125, 327 p. [Also available at https://doi.org/​10.3133/​ofr20201125.]

14   Integrated Rangeland Fire Management Strategy Actionable Science Plan Assessment: Invasives, 2015–20 Shinneman, D.J., 2019, North American sagebrush steppe and shrubland, in Goldstein, M.I., and DellaSala, D.A., eds., Encyclopedia of the World’s Biomes, v. 3, no. 6, p. 505–515. [Also available at https://doi.org/​10.1016/​B978-​0-​ 12-​409548-​9.11982-​7.] Stiver, S.J., Apa, A.D., Bohne, J.R., Bunnell, S.D., Deibert, P.A., Gardner, S.C., Hilliard, M.A., McCarthy, C.W., and Schroeder, M.A., 2006, Greater sage-grouse comprehensive conservation strategy—Unpublished report: Cheyenne, Wyoming, Western Association of Fish and Wildlife Agencies, 442 p. [Also available at https://wdfw.wa.gov/​ publications/​01317/​wdfw01317.pdf.] Suring, L.H., Rowland, M.M., and Wisdom, M.J., 2005, Identifying species of conservation concern, in Wisdom, M.J., Rowland, M.M., and Suring, L.H., eds., Habitat threats in the sagebrush ecosystem—Methods of regional assessment and applications in the Great Basin: Lawrence, KS, Alliance Communications Group, p. 150–162. U.S. Department of the Interior [DOI], 2015, An integrated rangeland fire management strategy—The final report to the Secretary: Washington, D.C., U.S. Department of the Interior. [Also available at https:/​/www.fores​tsandrange​ lands.gov/​documents/​rangeland/​In​tegratedRa​ngelandFir​ eManagemen​tStrategy_​Fi​nalReportM​ay2015.pdf.]

U.S. Fish and Wildlife Service, 2013, Greater sage-grouse (Centrocercus urophasianus) Conservation objectives— Final report: Denver, Colorado, U.S. Fish and Wildlife Service, 115 p. [Also available at http:/​/www.sageg​ rouseiniti​ative.com/​wp-​content/​uploads/​2013/​07/​USFWS_​ Con​servationO​bjectives-​report.pdf.] Western Governors’ Association, 2017, Western governors’ national forest and rangeland management initiative—The chairman’s initiative of Montana Governor Steve Bullock: Denver, CO, USA, 32 p. [Also available at westgov.org/​ images/​files/​2017_​NFRMI_​Report_​for_​Web.pdf.] Western Governors’ Association, 2020, A toolkit for invasive annual grass management in the West: Denver, Colorado, Western Governors Association, 8 p. [Also available at https://westgov.org/images/editor/FINAL_Cheatgrass_Toolkit_July_2020.pdf.]

References Cited  15

Glossary Addressed Objective detailed in a Next Step that was addressed in the literature published between January 1, 2015, and December 31, 2020

Outstanding Objective detailed in a Next Step that was not addressed in the literature published between January 1, 2015, and December 31, 2020

Fire frequency The recurrence of fire in a given area over time

Plan IRFMS Actionable Science Plan (Integrated Rangeland Fire Management Strategy Actionable Science Plan Team, 2016)

Need A shared vision among researchers and managers of priority science required to fill knowledge gaps and inform the next generation of management strategies and tools Next step Science objectives (that is, new research, syntheses, and tools) required to address a Need Objective Science or research goals detailed as Next Steps in the Plan

Score Relative measure of the level of progress towards addressing the Next Steps established in a Need Topic One of five science themes identified in the Plan relevant to the management of sagebrush ecosystems

16   Integrated Rangeland Fire Management Strategy Actionable Science Plan Assessment: Invasives, 2015–20

Appendix 1. Literature Included in Scoring Next Steps for the Invasives Topic in the Actionable Science Plan The literature in this appendix is organized by Need and Next Step. Needs are defined as a shared vision among researchers and managers of priority science required to fill knowledge gaps and inform the next generation of management strategies and tools. Next Steps are defined as science objectives (that is, new research, syntheses, and tools) required to address a Need. Next Steps scored as 0.00 in table 2 are described as “Not addressed.” Next Steps that could not be assessed through literature review approach used (for example, development of databases) are described as “NA.”

Invasives Need 1

Boyte, S.P., Wylie, B.K., Gu, Y., and Major, D.J., 2020, Estimating abiotic thresholds for sagebrush condition class in the western United States: Rangeland Ecology and Management, v. 73, no. 2, p. 297–308. Boyte, S.P., Wylie, B.K., Rigge, M.B., and Dahal, D., 2018, Fusing MODIS with Landsat 8 data to downscale weekly normalized difference vegetation index estimates for central Great Basin rangelands, USA: GIScience & Remote Sensing, v. 55, no. 3, p. 376–399. Boyte, S.P., Wylie, B.K., and Major, D.J., 2019, Validating a time series of annual grass percent cover in the sagebrush ecosystem: Rangeland Ecology and Management, v. 72, no. 2, p. 347–359.

Improve understanding of the natural and anthropogenic factors that influence invasive plant species distributions, including invasion history, surface disturbance, habitat condition, and fire history, and determine whether those factors can help identify tradeoffs among alternative management approaches.

Bradley, B.A., Curtis, C.A., Fusco, E.J., Abatzoglou, J.T., Balch, J.K., Dadashi, S., and Tuanmu, M.N., 2018, Cheatgrass (Bromus tectorum) distribution in the intermountain western United States and its relationship to fire frequency, seasonality, and ignitions: Biological Invasions, v. 20, no. 6, p. 1493–1506.

Next Step 1a

Hak, J.C., and Comer, P.J., 2020, Modeling invasive annual grass abundance in the cold desert ecoregions of the interior western United States: Rangeland Ecology and Management, v. 73, no. 1, p. 171–180.

Develop high-resolution maps of the current distribution of cheatgrass (Bromus tectorum), and create mechanisms or geospatial tools to update the maps regularly. Anderson, K.E., Glenn, N.F., Spaete, L.P., Shinneman, D.J., Pilliod, D.S., Arkle, R.S., McIlroy, S.K., and Derryberry, D.R., 2018, Estimating vegetation biomass and cover across large plots in shrub and grass dominated drylands using terrestrial lidar and machine learning: Ecological Indicators, v. 84, p. 793–802. Barnett, D.T., Jarnevich, C., Chong, G.W., Stohlgren, T.J., Kumar, S., and Holcombe, T., 2017, Ecology and space—A case study in mapping harmful invasive species, in Brunn, S., and Dodge, M., eds., Mapping across academia: Dordrecht, Springer, p. 63–81. [Also available at https://doi.org/​10.1007/​978-​94-​024-​1011-​2_​4.] Bishop, T.B.B., Munson, S., Gill, R.A., Belnap, J., St Clair, S.B., and Petersen, S.L., 2019, Spatiotemporal patterns of cheatgrass invasion in Colorado Plateau National Parks: Landscape Ecology, v. 34, p. 925–941. Boyte, S.P., and Wylie, B.K., 2016, Near-real-time cheatgrass percent cover in the northern Great Basin, USA, 2015: Rangelands, v. 38, no. 5, p. 278–284.

Horning, N., Fleishman, E., Ersts, P.J., Fogarty, F.A., and Wohlfeil Zillig, M., 2020, Mapping of land cover with open-source software and ultra-high-resolution imagery acquired with unmanned aerial vehicles: Remote Sensing in Ecology and Conservation, v. 6, no. 4, p. 487–497. Irvine, K.M., Wright, W.J., Shanahan, E.K., and Rodhouse, T.J., 2019, Cohesive framework for modelling plant cover class data: Methods in Ecology and Evolution, v. 10, no. 10, p. 1749–1760. Jarnevich, C.S., Talbert, M., Morisette, J., Aldridge, C., Brown, C.S., Kumar, S., Manier, D., Talbert, C., and Holcombe, T., 2017, Minimizing effects of methodological decisions on interpretation and prediction in species distribution studies—An example with background selection: Ecological Modelling, v. 363, p. 48–56. Pastick, N.J., Dahal, D., Wylie, B.K., Parajuli, S., Boyte, S.P., and Wu, Z., 2020, Characterizing land surface phenology and exotic annual grasses in dryland ecosystems using Landsat and Sentinel-2 data in harmony: Remote Sensing, v. 12, article 725, 17 p. [Also available at https://doi.org/​ 10.3390/​rs12040725.]

Appendix 1. Literature Included in Scoring Next Steps for the Invasives Topic in the Actionable Science Plan   17 Pastick, N.J., Wylie, B.K., and Wu, Z.T., 2018, Spatiotemporal analysis of Landsat-8 and Sentinel-2 data to support monitoring of dryland ecosystems: Remote Sensing, v. 10, article 791, 15 p. [Also available at https://doi.org/​10.3390/​ rs10050791.] Rigge, M., Homer, C., Cleeves, L., Meyer, D.K., Bunde, B., Shi, H., Xian, G., Schell, S., and Bobo, M., 2020, Quantifying western U.S. rangelands as fractional components with multi-resolution remote sensing and in situ data: Remote Sensing, v. 12, no. 3, article 412, 26 p. [Also available at https:// doi.org/​10.3390/​rs12030412.] West, A.M., Evangelista, P.H., Jarnevich, C.S., and Schulte, D., 2018, A tale of two wildfires—Testing detection and prediction of invasive species distributions using models fit with topographic and spectral indices: Landscape Ecology, v. 33, no. 6, p. 969–984. West, A.M., Evangelista, P.H., Jarnevich, C.S., Kumar, S., Swallow, A., Luizza, M.W., and Chignell, S.M., 2017, Using multi-date satellite imagery to monitor invasive grass species distribution in post-wildfire landscapes—An iterative, adaptable approach that employs open-source data and software: International Journal of Applied Earth Observation and Geoinformation, v. 59, p. 135–146.

Next Step 1b Create high-resolution maps of the current distributions of other invasive nonnative annual grasses such as medusahead rye (Taeniatherum caput-medusae) and ventenata (Ventenata dubia). Bateman, T.M., Villalba, J.J., Ramsey, R.D., and Sant, E.D., 2020, A multi-scale approach to predict the fractional cover of medusahead: Rangeland Ecology and Management, v. 73, no. 4, p. 538–546. Bradley, B.A., 2016, Predicting abundance with presence-only models: Landscape Ecology, v. 31, no. 1, p. 19–30. Dronova, I., Spotswood, E.N., and Suding, K.N., 2017, Opportunities and constraints in characterizing landscape distribution of an invasive grass from very high resolution multi-spectral imagery: Frontiers in Plant Science, v. 8, article 890, 17 p. [Also available at https://doi.org/​10.3389/​ fpls.2017.00890.]

Next Step 1c Conduct a meta-analysis of literature addressing the distribution, spread, and environmental associations of cheatgrass. Focus on relationship between disturbance events and activities that affect cheatgrass abundance, including wildfire,

prescribed fire, grazing, roads, industrial activities and infrastructure, habitat treatments, and environmental conditions associated with cheatgrass abundance and dominance. James, J.J., Gornish, E.S., DiTomaso, J.M., Davy, J., Doran, M.P., Becchetti, T., Lile, D., Brownsey, P., and Laca, E.A., 2015, Managing medusahead (Taeniatherum caputmedusae) on rangeland—A meta-analysis of control effects and assessment of stakeholder needs: Rangeland Ecology and Management, v. 68, no. 3, p. 215–223. Scasta, J.D., Engle, D.M., Fuhlendorf, S.D., Redfearn, D.D., and Bidwell, T.G., 2015, Meta-analysis of exotic forages as invasive plants in complex multi-functioning landscapes: Invasive Plant Science and Management, v. 8, no. 3, p. 292–306.

Next Step 1d Map and model additional invasive plants. Prioritization of this work should consider potential of an invasive plant to negatively affect ecosystems, habitats, or both. Bradley, B.A., 2016, Predicting abundance with presence-only models: Landscape Ecology, v. 31, no. 1, p. 19–30.

Next Step 1e Develop locally specific spatially-explicit soil maps, including soil temperature and moisture estimates, to inform spatial models and decision support tools at managementrelevant scales. Balzotti, C.S., Kitchen, S.G., and McCarthy, C., 2016, Beyond the single species climate envelope—a multifaceted approach to mapping climate change vulnerability: Ecosphere, v. 7, no. 9, 23 p. Boyte, S.P., Wylie, B.K., and Major, D.J., 2016, Cheatgrass percent cover change—Comparing recent estimates to climate change–driven predictions in the northern Great Basin: Rangeland Ecology and Management, v. 69, no. 4, p. 265–279.

18   Integrated Rangeland Fire Management Strategy Actionable Science Plan Assessment: Invasives, 2015–20 Chambers, J.C., Beck, J.L., Bradford, J.B., Bybee, J., Campbell, S., Carlson, J., Christiansen, T.J., Clause, K.J., Collins, G., Crist, M.R., Dinkins, J.B., Doherty, K.E., Edwards, F., Espinosa, S., Griffin, K.A., Griffin, P., Haas, J.R., Hanser, S.E., Havlina, D.W., Henke, K.F., Hennig, J.D., Joyce, L.A., Kilkenny, F.M., Kulpa, S.M., Kurth, L.L., Maestas, J.D., Manning, M., Mayer, K.E., Mealor, B.A., McCarthy, C., Pellant, M., Perea, M.A., Prentice, K.L., Pyke, D.A., Wiechman, L.A., and Wuenschel, A., 2017, Science framework for conservation and restoration of the sagebrush biome—Linking the Department of the Interior’s Integrated Rangeland Fire Management Strategy to long-term strategic conservation actions—Part 1. Science basis and applications: Fort Collins, Colorado, U.S. Forest Service, Rocky Mountain Research Station, General Technical Report RMRS-GTR-360, 213 p. [Also available at http​s://www.fs​.usda.gov/​treesearch/​pubs/​53983.] Palmquist, K.A., Schlaepfer, D.R., Bradford, J.B., and Lauenroth, W.K., 2016a, Mid-latitude shrub steppe plant communities—Climate change consequences for soil water resources: Ecology, v. 97, no. 9, p. 2342–2354. Palmquist, K.A., Schlaepfer, D.R., Bradford, J.B., and Lauenroth, W.K., 2016b, Spatial and ecological variation in dryland ecohydrological responses to climate change— Implications for management: Ecosphere, v. 7, no. 11, 20 p.

Next Step 1f Review the literature about the role of weather and climate in facilitating the spread of nonnative annual grasses. Belnap, J., Stark, J.M., Rau, B.M., Allen, E.B., and Phillips, S., 2016, Soil moisture and biogeochemical factors influence the distribution of annual Bromus species, in Germino, M.J., Chambers, J.C., and Brown, C.S., eds., Exotic bromegrasses in arid and semiarid ecosystems of the western U.S: Switzerland, Springer International Publishing, p. 227–256. Bradley, B.A., Curtis, C.A., and Chambers, J.C., 2016, Bromus response to climate and projected changes with climate change, in Germino, M.J., Chambers, J.C., and Brown, C.S., eds., Exotic brome-grasses in arid and semiarid ecosystems of the western U.S: Switzerland, Springer International Publishing, p. 257–274. Hufft, R.A., and Zelikova, T.J., 2016, Ecological genetics, local adaptation, and phenotypic plasticity in Bromus tectorum in the context of a changing climate, in Germino, M.J., Chambers, J.C., and Brown, C.S., eds., Exotic bromegrasses in arid and semiarid ecosystems of the western U.S: Switzerland, Springer International Publishing, p. 133–154.

Reeves, M.C., Manning, M.E., DiBenedetto, J.P., Palmquist, K.A., Lauenroth, W.K., Bradford, J.B., and Schlaepfer, D.R., 2018, Effects of climate change on rangeland vegetation in the Northern Rockies, in Halofsky, J., and Peterson, D., eds., Climate change and Rocky Mountain ecosystems v. 63: Advances in Global Change Research, p. 97–114. Zefferman, E., Stevens, J.T., Charles, G.K., Dunbar-Irwin, M., Emam, T., Fick, S., Morales, L.V., Wolf, K.M., Young, D.J.N., and Young, T.P., 2015, Plant communities in harsh sites are less invaded—A summary of observations and proposed explanations: AoB Plants, v. 7, 21 p. [Also available at https://doi.org/​10.1093/​aobpla/​plv056.]

Next Step 1g Initiate treatment and restoration experiments using cooperative efforts between management and research. Distribute study areas across the region using environmental gradients to capture and explain variability in response, seeking single or combined treatments that “mimic” positive effects of disturbance on habitat quality, and that minimize stimulation of nonnative annual grasses, annual forbs, and perennial invaders. Adler, P.B., Kleinhesselink, A., Hooker, G., Taylor, J.B., Teller, B., and Ellner, S.P., 2018, Weak interspecific interactions in a sagebrush steppe? Conflicting evidence from observations and experiments: Ecology, v. 99, no. 7, p. 1621–1632. Barnard, D.M., Germino, M.J., Arkle, R.S., Bradford, J.B., Duniway, M.C., Pilliod, D.S., Pyke, D.A., Shriver, R.K., and Welty, J.L., 2019, Soil characteristics are associated with gradients of big sagebrush canopy structure after disturbance: Ecosphere, v. 10, no. 6, 12 p. Bishop, T.B.B., Nusink, B.C., Lee Molinari, R., Taylor, J.B., and St. Clair, S.B., 2020, Earlier fall precipitation and low severity fire impacts on cheatgrass and sagebrush establishment: Ecosphere, v. 11, no. 1, 13 p. Clements, C.D., Harmon, D.N., Blank, R.R., and Weltz, M., 2017, Improving seeding success on cheatgrass-infested rangelands in Northern Nevada: Rangelands, v. 39, no. 6, p. 174–181. Davidson, B.E., Germino, M.J., Richardson, B., and Barnard, D.M., 2019, Landscape and organismal factors affecting sagebrush‐seedling transplant survival after megafire restoration: Restoration Ecology, v. 27, no. 5, p. 1008–1020. Davidson, B.E., Novak, S.J., and Serpe, M.D., 2016, Consequences of inoculation with native arbuscular mycorrhizal fungi for root colonization and survival of Artemisia tridentata ssp. wyomingensis seedlings after transplanting: Mycorrhiza, v. 26, no. 6, p. 595–608.

Appendix 1. Literature Included in Scoring Next Steps for the Invasives Topic in the Actionable Science Plan   19 Davies, K.W., Bates, J.D., and Clenet, D., 2020, Improving restoration success through microsite selection—An example with planting sagebrush seedlings after wildfire: Restoration Ecology, v. 28, no. 4, p. 859–868.

Nafus, A.M., Svejcar, T.J., Ganskopp, D.C., and Davies, K.W., 2015, Abundances of coplanted native bunchgrasses and crested wheatgrass after 13 years: Rangeland Ecology and Management, v. 68, no. 2, p. 211–214.

Hardegree, S.P., Sheley, R.L., Duke, S.E., James, J.J., Boehm, A.R., and Flerchinger, G.N., 2016, Temporal variability in microclimatic conditions for grass germination and emergence in the sagebrush steppe: Rangeland Ecology and Management, v. 69, no. 2, p. 123–128.

Porensky, L.M., Perryman, B.L., Williamson, M.A., Madsen, M.D., and Leger, E.A., 2018, Combining active restoration and targeted grazing to establish native plants and reduce fuel loads in invaded ecosystems: Ecology and Evolution, v. 8, no. 24, p. 12533–12546.

Herget, M.E., Hufford, K.M., Mummey, D.L., Mealor, B.A., and Shreading, L.N., 2015, Effects of competition with Bromus tectorum on early establishment of Poa secunda accessions—Can seed source impact restoration success?: Restoration Ecology, v. 23, no. 3, p. 277–283.

Rigby, C.W., Jensen, K.B., Creech, J.E., Thacker, E.T., Waldron, B.L., and Derner, J.D., 2018, Establishment and trends in persistence of selected perennial cool-season grasses in western United States: Rangeland Ecology and Management, v. 71, no. 6, p. 681–690.

Herriman, K.R., Davis, A.S., Apostol, K.G., Kildisheva, O.A., Ross-Davis, A.L., and Dumroese, R.K., 2016, Do container volume, site preparation, and field fertilization affect restoration potential of Wyoming big sagebrush?: Natural Areas Journal, v. 36, no. 2, p. 194–201.

Serpe, M.D., Thompson, A., and Petzinger, E., 2020, Effects of a companion plant on the formation of mycorrhizal propagules in Artemisia tridentata seedlings: Rangeland Ecology and Management, v. 73, no. 1, p. 138–146.

Holthuijzen, M.F., and Veblen, K.E., 2015, Grass-shrub associations over a precipitation gradient and their implications for restoration in the Great Basin, USA: PLoS ONE, v. 10, no. 12, 19 p. [Also available at https://doi.org/​10.1371/​ journal.pone.0143170.] James, J.J., Sheley, R.L., Leger, E.A., Adler, P.B., Hardegree, S.P., Gornish, E.S., and Rinella, M.J., 2019, Increased soil temperature and decreased precipitation during early life stages constrain grass seedling recruitment in cold desert restoration: Journal of Applied Ecology, v. 56, no. 12, p. 2609–2619. Johnston, D.B., 2019, Rough soil surface lessens annual grass invasion in disturbed rangeland: Rangeland Ecology and Management, v. 72, no. 2, p. 292–300. McAdoo, J.K., Swanson, J.C., Murphy, P.J., and Shaw, N.L., 2017, Evaluating strategies for facilitating native plant establishment in northern Nevada crested wheatgrass seedings—Native plant establishment in crested wheatgrass: Restoration Ecology, v. 25, no. 1, p. 53–62. Morris, C., Morris, L.R., and Monaco, T.A., 2019, Evaluating the effectiveness of low soil-disturbance treatments for improving native plant establishment in stable crested wheatgrass stands: Rangeland Ecology and Management, v. 72, no. 2, p. 237–248. Mummey, D.L., and Ramsey, P.W., 2017, Can sainfoin improve conditions for establishment of native forbs in crested wheatgrass stands?: Ecological Restoration, v. 35, no. 2, p. 127–137.

Stonecipher, C.A., Panter, K.E., Jensen, K.B., Rigby, C.W., and Villalba, J.J., 2017, Revegetation of medusaheadinvaded rangelands in the Channeled Scablands of eastern Washington: Rangeland Ecology and Management, v. 70, no. 3, p. 388–395.

Next Step 1h Conduct studies aimed at understanding the distribution, spread, and environmental associations of other rapidly spreading nonnative annual grasses (for example, medusahead rye and ventenata), including the effects of weather and climate. Esposito, D.M., Rodhouse, T.J., Mata-Gonzalez, R., and Hovland, M., 2019, Differential species responses to aspects of resistance to invasion in two Columbia Plateau-protected areas: Rangeland Ecology and Management, v. 72, no. 5, p. 773–782. Gornish, E.S., Case, E., Valle, M., Bean, T.M., and MooreO’Leary, K.A., 2018, A systematic review of management efforts on goatgrass (Aegilops ssp.) dominance: Plant Ecology, v. 219, no. 5, p. 549–560. Harvey, A.J., Rew, L.J., Prather, T.S., and Mangold, J.M., 2020, Effects of elevated temperature and CO2 concentration on seedling growth of Ventenata dubia (Leers) Coss. and Bromus tectorum L: Agronomy, v. 10, no. 11, article 1718, 9 p. [Also available at https://doi.org/​10.3390/​ agronomy10111718.]

20   Integrated Rangeland Fire Management Strategy Actionable Science Plan Assessment: Invasives, 2015–20 James, J.J., Gornish, E.S., DiTomaso, J.M., Davy, J., Doran, M.P., Becchetti, T., Lile, D., Brownsey, P., and Laca, E.A., 2015, Managing medusahead (Taeniatherum caputmedusae) on rangeland—A meta-analysis of control effects and assessment of stakeholder needs: Rangeland Ecology and Management, v. 68, no. 3, p. 215–223. Jones, L.C., Davis, C., and Prather, T.S., 2020, Consequences of Ventenata dubia 30 years postinvasion to bunchgrass communities in the Pacific Northwest: Invasive Plant Science and Management, v. 13, no. 4, p. 226–238. Jones, R.O., Chambers, J.C., Board, D.I., Johnson, D.W., and Blank, R.R., 2015, The role of resource limitation in restoration of sagebrush ecosystems dominated by cheatgrass (Bromus tectorum): Ecosphere, v. 6, no. 7, article 107, 21 p. [Also available at http://dx.doi.org/​10. 1890/ES14-00285.1.] Nicolli, M., Rodhouse, T.J., Stucki, D.S., and Shinderman, M., 2020, Rapid invasion by the annual grass Ventenata dubia into protected-area, low-elevation sagebrush steppe: Western North American Naturalist, v. 80, no. 2, p. 243–252. Pervukhina-Smith, I., Sforza, R.F.H., Cristofaro, M., Smith, J.F., and Novak, S.J., 2020, Genetic analysis of invasive populations of Ventenata dubia (Poaceae)—An assessment of propagule pressure and pattern of range expansion in the western United States: Biological Invasions, v. 22, no. 12, p. 3575–3592. Ploughe, L.W., Carlyle, C.N., and Fraser, L.H., 2020, Priority effects—How the order of arrival of an invasive grass, Bromus tectorum, alters productivity and plant community structure when grown with native grass species: Ecology and Evolution, v. 10, no. 23, p. 13173–13181. Tortorelli, C.M., Krawchuk, M.A., and Kerns, B.K., 2020, Expanding the invasion footprint—Ventenata dubia and relationships to wildfire, environment, and plant communities in the Blue Mountains of the Inland Northwest, USA: Applied Vegetation Science, v. 23, no. 4, p. 562–574.

Next Step 1i Conduct integrated landscape (remote-sensing) and local (field-based) assessment of post-disturbance recovery rates to assess differences in rates and composition due to climate, soils herbivory, land use, and other environmental patterns. Assess implications of recovered areas for wildlife use, fuel dynamics and fire potential, and ecosystem services. Holbrook, J.D., Arkle, R.S., Rachlow, J.L., Vierling, K.T., Pilliod, D.S., and Wiest, M.M., 2016, Occupancy and abundance of predator and prey—Implications of the firecheatgrass cycle in sagebrush ecosystems: Ecosphere, v. 7, no. 6, 21 p.

Holbrook, J.D., Pilliod, D.S., Arkle, R.S., Rachlow, J.L., Vierling, K.T., and Wiest, M.M., 2016, Transition of vegetation states positively affects harvester ants in the Great Basin, United States: Rangeland Ecology and Management, v. 69, no. 6, p. 449–456. St. Clair, S.B., O’Connor, R., Gill, R., and McMillan, B., 2016, Biotic resistance and disturbance—Rodent consumers regulate post-fire plant invasions and increase plant community diversity: Ecology, v. 97, no. 7, p. 1700–1711.

Next Step 1j Also refer to Invasives Science Need 4, long-term next steps. NA.

Studies Related to Need 1, but Not Any of the Next Steps Bansal, S., and Sheley, R.L., 2016, Annual grass invasion in sagebrush steppe—The relative importance of climate, soil properties and biotic interactions: Oecologia, v. 181, no. 2, p. 543–557. Brummer, T.J., Taylor, K.T., Rotella, J., Maxwell, B.D., Rew, L.J., and Lavin, M., 2016, Drivers of Bromus tectorum abundance in the western North American sagebrush steppe: New York, Ecosystems, v. 19, no. 6, p. 986–1000. Clark, S.L., 2020, Using herbicides to restore native species and improve habitat on rangelands and wildlands: Outlooks on Pest Management, v. 31, no. 2, p. 57–60. Hejda, M., Stajerova, K., Pergl, J., and Pysek, P., 2019, Impacts of dominant plant species on trait composition of communities—comparison between the native and invaded ranges: Ecosphere, v. 10, no. 10, 14 p. Howell, A., Winkler, D.E., Phillips, M.L., McNellis, B., and Reed, S.C., 2020, Experimental warming changes phenology and shortens growing season of the dominant invasive plant Bromus tectorum (cheatgrass): Frontiers in Plant Science, v. 11, 15 p. Jones, L.C., Norton, N., and Prather, T.S., 2018, Indicators of ventenata invasion in sagebrush steppe rangeland: Invasive Plant Science and Management, v. 11, no. 1, p. 1–9. Lamar, S.K., Beddows, I., and Partridge, C.G., 2020, Examining the molecular mechanisms contributing to the success of an invasive species across different ecosystems: Ecology and Evolution, v. 10, no. 18, p. 10254–10270.

Appendix 1. Literature Included in Scoring Next Steps for the Invasives Topic in the Actionable Science Plan   21 Lawrence, N.C., Hauvermale, A.L., and Burke, I.C., 2018, Downy brome (Bromus tectorum) vernalization— Variation and genetic controls: Weed Science, v. 66, no. 3, p. 310–316. Leffler, A.J., Monaco, T.A., James, J.J., and Sheley, R.L., 2016, Importance of soil and plant community disturbance for establishment of Bromus tectorum in the Intermountain West, USA: NeoBiota, v. 30, p. 111–125. Lucero, J.E., Schaffner, U., Asadi, G., Bagheri, A., Rajabov, T., and Callaway, R.M., 2019, Enemy release from the effects of generalist granivores can facilitate Bromus tectorum invasion in the Great Basin desert: Ecology and Evolution, v. 9, no. 15, p. 8490–8499. Meyer, S.E., Leger, E.A., Eldon, D.R., and Coleman, C.E., 2016, Strong genetic differentiation in the invasive annual grass Bromus tectorum across the Mojave-Great Basin ecological transition zone: Biological Invasions, v. 18, no. 6, p. 1611–1628. Mosena, A., Steinlein, T., and Beyschlag, W., 2018, Reconstructing the historical spread of non-native plants in the North American West from herbarium specimens: Flora (Jena), v. 242, p. 45–52. Pawlak, A.R., Mack, R.N., Busch, J.W., and Novak, S.J., 2015, Invasion of Bromus tectorum into California and the American southwest—Rapid, multi-directional and genetically diverse: Biological Invasions, v. 17, no. 1, p. 287–306. Ricks, K.D., and Koide, R.T., 2019, Biotic filtering of endophytic fungal communities in Bromus tectorum: Oecologia, v. 189, no. 4, p. 993–1003. Slate, M.L., Callaway, R.M., and Pearson, D.E., 2019, Life in interstitial space—Biocrusts inhibit exotic but not native plant establishment in semi-arid grasslands: Journal of Ecology, v. 107, no. 3, p. 1317–1327. Smull, D.M., Pendleton, N., Kleinhesselink, A.R., and Adler, P.B., 2019, Climate change, snow mold and the Bromus tectorum invasion—Mixed evidence for release from cold weather pathogens: AoB Plants, v. 11, no. 5, 9 p. St. Clair, S.B., and Bishop, T.B.B., 2019, Loss of biotic resistance and high propagule pressure promote invasive grassfire cycles: Journal of Ecology, v. 107, no. 4, p. 1995–2005.

Invasives Need 2 Improve measures for prevention, eradication, and control of invasive plant species, and use risk assessments to weigh potential benefits and deleterious effects of different measures on native plant species.

Next Step 2a Investigate the complex interrelationships among various components within ecosystems that create multiple, indirect responses by invasive plant species to specific vegetationmanagement actions. Applestein, C., Germino, M.J., and Fisk, M.R., 2018, Vegetative community response to landscape-scale post-fire herbicide (imazapic) application: Invasive Plant Science and Management, v. 11, p. 127–135. [Also available at https://doi.org/​10.1017/​inp.2018.18.] Aryal, P., and Islam, M.A., 2018, Effect of forage kochia on seedling growth of cheatgrass (Bromus tectorum) and perennial grasses: Invasive Plant Science and Management, v. 11, no. 4, p. 201–207. Belnap, J., Stark, J.M., Rau, B.M., Allen, E.B., and Phillips, S., 2016, Soil moisture and biogeochemical factors influence the distribution of annual Bromus species, in Germino, M.J., Chambers, J.C., and Brown, C.S., eds., Exotic bromegrasses in arid and semiarid ecosystems of the western U.S: Switzerland, Springer International Publishing, p. 227–256. Blank, R.R., Clements, C., Morgan, T., Harmon, D., and Allen, F., 2020, Suppression of cheatgrass by perennial bunchgrasses: Rangeland Ecology and Management, v. 73, no. 6, p. 766–771. Blank, R.R., Mackey, B., and Morgan, T., 2016, Do a native and two exotic grasses respond differently in soils conditioned by native vegetation versus an exotic grass?: Rhizosphere, v. 2, p. 38–47. Blumenthal, D.M., LeCain, D.R., and Augustine, D.J., 2017, Composted manure application promotes long-term invasion of semi-arid rangeland by Bromus tectorum: Ecosphere, v. 8, no. 10, 12 p. Burnett, S.A., and Mealor, B.A., 2015, Imazapic effects on competition dynamics between native perennial grasses and downy brome (Bromus tectorum): Invasive Plant Science and Management, v. 8, no. 1, p. 72–80. Clark, S.L., da Silva, P.V., Dayan, F.E., Nissen, S.J., and Sebastian, D.J., 2019a, The influence of winter annual grass litter on herbicide availability: Weed Science, v. 67, no. 6, p. 702–709. Clark, S.L., Sebastian, D.J., Nissen, S.J., and Sebastian, J.R., 2019b, Effect of indaziflam on native species in natural areas and rangeland: Invasive Plant Science and Management, v. 12, no. 1, p. 60–67. Clark, S.L., Sebastian, D.J., Nissen, S.J., and Sebastian, J.R., 2020, Evaluating winter annual grass control and native species establishment following applications of indaziflam on rangeland: Invasive Plant Science and Management, v. 13, no. 3, p. 199–209.

22   Integrated Rangeland Fire Management Strategy Actionable Science Plan Assessment: Invasives, 2015–20 Condon, L.A., and Gray, M.L., 2020, Not all fuel-reduction treatments degrade biocrusts—Herbicides cause mostly neutral to positive effects on cover of biocrusts: Land Degradation & Development, v. 31, no. 13, p. 1727–1734.

Metier, E.P., Rew, L.J., and Rinella, M.J., 2018, Establishing Wyoming big sagebrush in annual brome-invaded landscapes with seeding and herbicide: Rangeland Ecology and Management, v. 71, no. 6, p. 705–713.

Davies, K.W., and Boyd, C.S., 2018, Longer-term evaluation of revegetation of medusahead-invaded sagebrush steppe: Rangeland Ecology and Management, v. 71, no. 3, p. 292–297.

Mitchell, R.M., Bakker, J.D., Vincent, J.B., and Davies, G.M., 2017, Relative importance of abiotic, biotic, and disturbance drivers of plant community structure in the sagebrush steppe: Ecological Applications, v. 27, no. 3, p. 756–768.

Davies, K.W., and Johnson, D.D., 2017, Established perennial vegetation provides high resistance to reinvasion by exotic annual grasses: Rangeland Ecology and Management, v. 70, no. 6, p. 748–754.

Morris, C., Morris, L.R., and Surface, C., 2016, Glyphosate application for selective control of downy brome (Bromus tectorum L.) on Great Basin rangelands: Weed Technology, v. 30, no. 1, p. 297–302.

Dierks, J., Denef, K., van Diepen, L.T.A., and de Graaff, M.A., 2019, Cheatgrass-associated AMF community negatively affects sagebrush root production but not C transfer to the soil: Plant and Soil, v. 436, no. 1–2, p. 381–396.

Orr, M.R., Reuter, R.J., and Murphy, S.J., 2019, Solarization to control downy brome (Bromus tectorum) for smallscale ecological restoration: Invasive Plant Science and Management, v. 12, no. 2, p. 112–119.

Foxx, A.J., and Kramer, A.T., 2020, Variation in number of root tips influences survival in competition with an invasive grass: Journal of Arid Environments, v. 179, 4 p.

Reed-Dustin, C.M., Mata-Gonzalez, R., and Rodhouse, T.J., 2016, Long-term fire effects on native and invasive grasses in protected area sagebrush steppe: Rangeland Ecology and Management, v. 69, no. 4, p. 257–264.

Jones, R., Chambers, J.C., Johnson, D.W., Blank, R.R., and Board, D.I., 2015a, Effect of repeated burning on plant and soil carbon and nitrogen in cheatgrass (Bromus tectorum) dominated ecosystems: Plant and Soil, v. 386, p. 47–64. Jones, R.O., Chambers, J.C., Board, D.I., Johnson, D.W., and Blank, R.R., 2015b, The role of resource limitation in restoration of sagebrush ecosystems dominated by cheatgrass (Bromus tectorum): Ecosphere, v. 6, no. 7, 21 p. Larson, C.D., Lehnhoff, E.A., and Rew, L.J., 2017, A warmer and drier climate in the northern sagebrush biome does not promote cheatgrass invasion or change its response to fire: Oecologia, v. 185, no. 4, p. 763–774. Larson, C.D., Lehnhoff, E.A., Noffsinger, C., and Rew, L.J., 2018, Competition between cheatgrass and bluebunch wheatgrass is altered by temperature, resource availability, and atmospheric CO2 concentration: Oecologia, v. 186, no. 3, p. 855–868. McKay, S., Morris, L.R., Morris, C.E., and Leger, E.A., 2017, Notes—Examining the potential competative effects of Ventenata dubia on annual and perennial grasses: Prairie Naturalist, v. 49, p. 19–22. Metier, E.P., Lehnhoff, E.A., Mangold, J., Rinella, M.J., and Rew, L.J., 2020, Control of downy brome (Bromus tectorum) and Japanese brome (Bromus japonicus) using glyphosate and four graminicides—Effects of herbicide rate, plant size, species, and accession: Weed Technology, v. 34, no. 2, p. 284–291.

Schantz, M., Sheley, R., and Hardegree, S., 2019, Restoring perennial grasses in medusahead habitat—Role of tilling, fire, herbicides, and seeding rate: Rangeland Ecology and Management, v. 72, no. 2, p. 249–259. Sebastian, D.J., Fleming, M.B., Patterson, E.L., Sebastian, J.R., and Nissen, S.J., 2017, Indaziflam—A new cellulosebiosynthesis-inhibiting herbicide provides long-term control of invasive winter annual grasses: Pest Management Science, v. 73, no. 10, p. 2149–2162. Sebastian, D.J., Nissen, S.J., and De Souza Rodrigues, J., 2016, Pre-emergence control of six invasive winter annual grasses with imazapic and indaziflam: Invasive Plant Science and Management, v. 9, no. 4, p. 308–316. Seipel, T., Rew, L.J., Taylor, K.T., Maxwell, B.D., and Lehnhoff, E.A., 2018, Disturbance type influences plant community resilience and resistance to Bromus tectorum invasion in the sagebrush steppe: Applied Vegetation Science, v. 21, no. 3, p. 385–394. Stonecipher, C.A., Thacker, E., Welch, K.D., Ralphs, M.H., and Monaco, T.A., 2019, Long-term persistence of coolseason grasses planted to suppress broom snakeweed, downy brome, and weedy forbs: Rangeland Ecology and Management, v. 72, no. 2, p. 266–274. Swanson, S.R., Swanson, J.C., Murphy, P.J., McAdoo, J.K., and Schultz, B., 2016, Mowing Wyoming big sagebrush (Artemisia tridentata ssp. wyomingensis) cover effects across northern and central Nevada: Rangeland Ecology and Management, v. 69, no. 5, p. 360–372.

Appendix 1. Literature Included in Scoring Next Steps for the Invasives Topic in the Actionable Science Plan   23 Uselman, S.M., Snyder, K.A., Leger, E.A., and Duke, S.E., 2015, Emergence and early survival of early versus late seral species in Great Basin restoration in two different soil types: Applied Vegetation Science, v. 18, no. 4, p. 624–636.

Lucero, J.E., and Callaway, R.M., 2018, Native granivores reduce the establishment of native grasses but not invasive Bromus tectorum: Biological Invasions, v. 20, no. 12, p. 3491–3497.

Wade, C.E., and Loik, M.E., 2017, A spring rainfall pulse causes greater in situ photosynthetic upregulation for Bromus tectorum compared to co-occurring native herbaceous species: Environmental and Experimental Botany, v. 143, p. 51–58.

Rinella, M.J., Davy, J.S., Kyser, G.B., Mashiri, F.E., Bellows, S.E., James, J.J., and Peterson, V.F., 2018, Timing aminopyralid to prevent seed production controls medusahead (Taeniatherum caput-medusae) and increases forage grasses: Invasive Plant Science and Management, v. 11, no. 1, p. 61–68.

Next Step 2b Develop guidelines to evaluate causes of invasion, succession, and retrogression (for example, cheatgrass die-off). Belnap, J., Stark, J.M., Rau, B.M., Allen, E.B., and Phillips, S., 2016, Soil moisture and biogeochemical factors influence the distribution of annual Bromus species, in Germino, M.J., Chambers, J.C., and Brown, C.S., eds., Exotic bromegrasses in arid and semiarid ecosystems of the western U.S: Switzerland, Springer International Publishing, p. 227–256. Bishop, T.B.B., Munson, S., Gill, R.A., Belnap, J., Petersen, S.L., and St Clair, S.B., 2019, Spatiotemporal patterns of cheatgrass invasion in Colorado Plateau National Parks: Landscape Ecology, v. 34, p. 925–941. James, J.J., Gornish, E.S., DiTomaso, J.M., Davy, J., Doran, M.P., Becchetti, T., Lile, D., Brownsey, P., and Laca, E.A., 2015, Managing medusahead (Taeniatherum caputmedusae) on rangeland—A meta-analysis of control effects and assessment of stakeholder needs: Rangeland Ecology and Management, v. 68, no. 3, p. 215–223.

Next Step 2c Investigate strategies for prevention of new plant invasions that are based on the ecology of seed dispersal. Berleman, S.A., Suding, K.N., Fry, D.L., Bartolome, J.W., and Stephens, S.L., 2016, Prescribed fire effects on population dynamics of an annual grassland: Rangeland Ecology and Management, v. 69, no. 6, p. 423–429. Johnston, D.B., 2019, Rough soil surface lessens annual grass invasion in disturbed rangeland: Rangeland Ecology and Management, v. 72, no. 2, p. 292–300. Leger, E.A., and Goergen, E.M., 2017, Invasive Bromus tectorum alters natural selection in arid systems: Journal of Ecology, v. 105, no. 6, p. 1509–1520. Lucero, J.E., 2018, Do seeds from invasive bromes experience less granivory than seeds from native congeners in the Great Basin Desert?: Plant Ecology, v. 219, no. 9, p. 1053–1061.

Next Step 2d Investigate the potential for integrating invasive plant management within a systems approach to facilitate problem solving and the attainment of well-defined goals, rather than practice-based outcomes. Chambers, J.C., Brooks, M.L., Germino, M.J., Maestas, J.D., Board, D.I., Jones, M.O., and Allred, B.W., 2019, Operationalizing resilience and resistance concepts to address invasive grass-fire cycles: Frontiers in Ecology and Evolution, v. 7, 25 p. Chambers, J.C., Germino, M.J., Belnap, J., Brown, C.S., Schupp, E.W., and St Clair, S.B., 2016, Plant community resistance to invasion by Bromus species—The roles of community attributes, Bromus interactions with plant communities, and Bromus traits, in Germino, M.J., Chambers, J.C., and Brown, C.S., eds., Exotic brome-grasses in arid and semiarid ecosystems of the western U.S: Switzerland, Springer International Publishing, p. 275–304. Chambers, J.C., Maestas, J.D., Pyke, D.A., Boyd, C.S., Pellant, M., and Wuenshel, A., 2017, Using resilience and resistance concepts to manage persistent threats to sagebrush ecosystems and greater sage-grouse: Rangeland Ecology and Management, v. 70, no. 2, p. 149–164. Hulet, A., Boyd, C.S., Davies, K.W., and Svejcar, T.J., 2015, Prefire (preemptive) management to decrease fire-induced bunchgrass mortality and reduce reliance on postfire seeding: Rangeland Ecology and Management, v. 68, no. 6, p. 437–444. James, J.J., and Carrick, P.J., 2016, Toward quantitative dryland restoration models: Restoration Ecology, v. 24, no. S2, p. S85–S90. Smith, B.S., and Sheley, R.L., 2015, Implementing strategic weed prevention programs to protect rangeland ecosystems: Invasive Plant Science and Management, v. 8, no. 2, p. 233–242.

24   Integrated Rangeland Fire Management Strategy Actionable Science Plan Assessment: Invasives, 2015–20 Svejcar, T., Boyd, C., Davies, K., Hamerlynck, E., and Svejcar, L., 2017, Challenges and limitations of native species restoration in the Great Basin, USA: Plant Ecology, v. 218, no. 1, p. 81–94.

Next Step 2e Develop a conceptual framework and associated tools that assist in identifying which vectors are major contributors to invasive plant species dispersal. Then develop dispersalmanagement strategies to minimize or interrupt these major vectors. Spackman, C.N., Monaco, T.A., Stonecipher, C.A., and Villalba, J.J., 2020, Plant silicon as a factor in medusahead (Taeniatherum caput-medusae) invasion: Invasive Plant Science and Management, v. 13, no. 3, p. 143–154. Strickland, C., Dangelmayr, G., Shipman, P.D., Kumar, S., and Stohlgren, T.J., 2015, Network spread of invasive species and infectious diseases: Ecological Modelling, v. 309–310, p. 1–9.

Studies Related to Need 2, but Not Any of the Next Steps Clements, C.D., Harmon, D.N., Blank, R.R., and Weltz, M., 2017, Improving seeding success on cheatgrass-infested rangelands in northern Nevada: Rangelands, v. 39, no. 6, p. 174–181. Hergert, H.J., Mealor, B.A., and Kniss, A.R., 2015, Interand intraspecific variation in native restoration plants for herbicide tolerance: Ecological Restoration, v. 33, no. 1, p. 74–81. Jabran, K., and Dogan, M.N., 2018, High carbon dioxide concentration and elevated temperature impact the growth of weeds but do not change the efficacy of glyphosate: Pest Management Science, v. 74, no. 3, p. 766–771. Johnston, D.B., 2015, Downy brome (Bromus tectorum) control for pipeline restoration: Invasive Plant Science and Management, v. 8, no. 2, p. 181–192. Rinella, M.J., Knudsen, A.D., Jacobs, J.S., and Mangold, J.M., 2020, Seeding causes long-term increases in grass forage production in invaded rangelands: Rangeland Ecology and Management, v. 73, no. 2, p. 329–333.

Invasives Need 3 Conduct invasive plant inventory, including spatial data on infestations and current range maps, to improve the ability for managers to prioritize actions to prevent and control nonnative plant populations before they become established and spread.

Next Step 3a Initiate standardized early-season field collection to inform early detection efforts and map development. See Next Step 3b citations.

Next Step 3b Develop nonnative annual grass spatial datasets to inform annual predictive fire models and identify of potential treatment areas. Boyte, S.P., and Wylie, B.K., 2016, Near-real-time cheatgrass percent cover in the northern Great Basin, USA, 2015: Rangelands, v. 38, no. 5, p. 278–284. Boyte, S.P., Wylie, B.K., Major, D.J., and Brown, J.F., 2015, The integration of geophysical and enhanced Moderate Resolution Imaging Spectroradiometer Normalized Difference Vegetation Index data into a rule-based, piecewise regression-tree model to estimate cheatgrass beginning of spring growth: International Journal of Digital Earth, v. 8, no. 2, p. 118–132. Bradley, B.A., Curtis, C.A., Fusco, E.J., Abatzoglou, J.T., Balch, J.K., Dadashi, S., and Tuanmu, M.N., 2018, Cheatgrass (Bromus tectorum) distribution in the intermountain western United States and its relationship to fire frequency, seasonality, and ignitions: Biological Invasions, v. 20, no. 6, p. 1493–1506. Fusco, E.J., Finn, J.T., Balch, J.K., Nagy, R.C., and Bradley, B.A., 2019, Invasive grasses increase fire occurrence and frequency across US regions: Proceedings of the National Academy of Sciences of the United States of America, v. 116, no. 47, p. 23594–23599.

Next Step 3c Develop a centralized clearinghouse of occurrence data for invasive plants that aggregates data from existing data entry systems and databases. Barker, B.S., Pilliod, D.S., Welty, J.L., Arkle, R.S., Karl, M.G., and Toevs, G.R., 2018, An introduction and practical guide to use of the soil-vegetation inventory method (SVIM) data: Rangeland Ecology and Management, v. 71, no. 6, p. 671–680.

Appendix 1. Literature Included in Scoring Next Steps for the Invasives Topic in the Actionable Science Plan   25

Next Step 3d

Invasives Need 4

Develop datasets to map current cheatgrass and sagebrush extent and productivity, in relation to annual weather conditions, that will readily integrate into fire models to identify spatially explicit fire probabilities, and enable prediction of future cheatgrass distributions using projected climate scenarios.

Assess effectiveness of targeted grazing with livestock to reduce nonnative annual grasses and understand the impact on native plants in the sagebrush ecosystem.

Bradley, B.A., Curtis, C.A., Fusco, E.J., Abatzoglou, J.T., Balch, J.K., Dadashi, S., and Tuanmu, M.N., 2018, Cheatgrass (Bromus tectorum) distribution in the intermountain western United States and its relationship to fire frequency, seasonality, and ignitions: Biological Invasions, v. 20, no. 6, p. 1493–1506. Fusco, E.J., Finn, J.T., Balch, J.K., Nagy, R.C., and Bradley, B.A., 2019, Invasive grasses increase fire occurrence and frequency across US regions: Proceedings of the National Academy of Sciences of the United States of America, v. 116, no. 47, p. 23594–23599. Pilliod, D.S., Welty, J.L., and Arkle, R.S., 2017, Refining the cheatgrass-fire cycle in the Great Basin—Precipitation timing and fine fuel composition predict wildfire trends: Ecology and Evolution, v. 7, no. 19, p. 8126–8151.

Studies Related to Need 3, but Not Any of the Next Steps Boyte, S.P., Wylie, B.K., and Major, D.J., 2016, Cheatgrass percent cover change—Comparing recent estimates to climate change–driven predictions in the northern Great Basin: Rangeland Ecology and Management, v. 69, no. 4, p. 265–279. Brummer, T.J., Taylor, K.T., Rotella, J., Maxwell, B.D., Rew, L.J., and Lavin, M., 2016, Drivers of Bromus tectorum abundance in the western North American sagebrush steppe: New York, Ecosystems, v. 19, no. 6, p. 986–1000. Pastick, N.J., Dahal, D., Wylie, B.K., Parajuli, S., Boyte, S.P., and Wu, Z., 2020, Characterizing land surface phenology and exotic annual grasses in dryland ecosystems using Landsat and Sentinel-2 data in harmony: Remote Sensing, v. 12, 17 p. [Also available at https://doi.org/​10.3390/​ rs12040725.] Pastick, N.J., Wylie, B.K., and Wu, Z.T., 2018, Spatiotemporal analysis of Landsat-8 and Sentinel-2 data to support monitoring of dryland ecosystems: Remote Sensing, v. 10, article 791, 15 p. [Also available at https://doi.org/​10.3390/​ rs10050791.]

Next Step 4a Implement and intensively monitor landscape-level, targeted-grazing demonstration projects to strategically reduce fine fuels. Davies, K.W., Boyd, C.S., Bates, J.D., and Hulet, A., 2015, Dormant season grazing may decrease wildfire probability by increasing fuel moisture and reducing fuel amount and continuity: International Journal of Wildland Fire, v. 24, no. 6, p. 849–856. Lehnhoff, E.A., Rew, L.J., Mangold, J.M., Seipel, T., and Ragen, D., 2019, Integrated management of cheatgrass (Bromus tectorum) with sheep grazing and herbicide: Agronomy, v. 9, 21 p. [Also available at https://doi.org/​ 10.3390/​agronomy9060315.] Montes-Sánchez, J.J., Van Miegroet, H., and Villalba, J.J., 2017, Effects of energy supplementation and time on use of medusahead by grazing ewes with their lambs: Rangeland Ecology and Management, v. 70, no. 3, p. 380–387. Porensky, L.M., Perryman, B.L., Williamson, M.A., Madsen, M.D., and Leger, E.A., 2018, Combining active restoration and targeted grazing to establish native plants and reduce fuel loads in invaded ecosystems: Ecology and Evolution, v. 8, no. 24, p. 12533–12546. Rinella, M.J., and Bellows, S.E., 2016, Evidence-targeted grazing benefits to invaded rangelands can increase over extended time frames: Rangeland Ecology and Management, v. 69, no. 3, p. 169–172.

Next Step 4b Implement and assess several projects to establish grazed “fire breaks” in combination with other fuel treatment methods, determining relative importance of targeted grazing versus other treatments. NA.

Next Step 4c Determine thresholds of residual herbaceous fuels required to alter fire behavior and facilitate suppression under various weather conditions.

26   Integrated Rangeland Fire Management Strategy Actionable Science Plan Assessment: Invasives, 2015–20 Davies, K.W., Bates, J.D., Boyd, C.S., and Svejcar, T.J., 2016, Prefire grazing by cattle increases postfire resistance to exotic annual grass (Bromus tectorum) invasion and dominance for decades: Ecology and Evolution, v. 6, no. 10, p. 3356–3366.

Next Step 4e

Davies, K.W., Boyd, C.S., Bates, J.D., and Hulet, A., 2015a, Dormant season grazing may decrease wildfire probability by increasing fuel moisture and reducing fuel amount and continuity: International Journal of Wildland Fire, v. 24, no. 6, p. 849–856.

Davies, K.W., Bates, J.D., and Boyd, C.S., 2020, Response of planted sagebrush seedlings to cattle grazing applied to decrease fire probability: Rangeland Ecology and Management, v. 73, no. 5, p. 629–635.

Evaluate the potential role of livestock grazing to reduce fuel loads in mixed shrub and grass vegetation types in the short-term.

Davies, K.W., Boyd, C.S., Bates, J.D., and Hulet, A., 2015b, grazing can reduce wildfire size, intensity and behaviour in a shrub-grassland: International Journal of Wildland Fire, v. 25, no. 2, p. 191–199.

Davies, K.W., Boyd, C.S., Bates, J.D., and Hulet, A., 2015, Dormant season grazing may decrease wildfire probability by increasing fuel moisture and reducing fuel amount and continuity: International Journal of Wildland Fire, v. 24, no. 6, p. 849–856.

Davies, K.W., Boyd, C.S., Bates, J.D., and Hulet, A., 2016, Winter grazing decreases the probability of fire-induced mortality of bunchgrasses and may reduce wildfire size—A response to Smith et al.: International Journal of Wildland Fire, v. 25, no. 4, p. 489–493.

Dittel, J.W., Sanchez, D., Ellsworth, L.M., Morozumi, C.N., and Mata-Gonzalez, R., 2018, Vegetation response to juniper reduction and grazing exclusion in sagebrushsteppe habitat in eastern Oregon: Rangeland Ecology and Management, v. 71, no. 2, p. 213–219.

Davies, K.W., Gearhart, A., Boyd, C.S., and Bates, J.D., 2017, Fall and spring grazing influence fire ignitability and initial spread in shrub steppe communities: International Journal of Wildland Fire, v. 26, no. no. 6, p. 485–490.

Veblen, K.E., Nehring, K.C., McGlone, C.M., and Ritchie, M.E., 2015, Contrasting effects of different mammalian herbivores on sagebrush plant communities: PLoS ONE, v. 10, no. 2, 19 p. [Also available at https://doi.org/​10.1371/​ journal.pone.0118016.]

Davies, K.W., Nafus, A.M., Boyd, C.S., Hulet, A., and Bates, J.D., 2016, Effects of using winter grazing as a fuel treatment on Wyoming big sagebrush plant communities: Rangeland Ecology and Management, v. 69, no. 3, p. 179–184. Li, Z., Shi, H., Vogelmann, J.E., Hawbaker, T.J., and Peterson, B., 2020, Assessment of fire fuel load dynamics in shrubland ecosystems in the western United States using MODIS products: Remote Sensing, v. 12, 17 p. [Also available at https:// doi.org/​10.3390/​rs12121911.] Smith, M.S.A., Talhelm, A.F., Kolden, C.A., Newingham, B.A., Adams, H.D., Cohen, J.D., Yedinak, K.M., and Kremens, R.L., 2016, The ability of winter grazing to reduce wildfire size and fire-induced plant mortality was not demonstrated—A comment on Davies et al. (2015): International Journal of Wildland Fire, v. 25, no. 4, p. 484–488.

Next Step 4d Evaluate the economic efficiencies of using targeted grazing as a short-term wildland fuel treatment. NA.

Next Step 4f Evaluate the rate, frequency, and timing of grazing events necessary to maintain targeted fuel levels. Davies, K.W., Bates, J.D., Boyd, C.S., and Svejcar, T.J., 2016a, Prefire grazing by cattle increases postfire resistance to exotic annual grass (Bromus tectorum) invasion and dominance for decades: Ecology and Evolution, v. 6, no. 10, p. 3356–3366. Davies, K.W., Boyd, C.S., Bates, J.D., and Hulet, A., 2015a, Dormant season grazing may decrease wildfire probability by increasing fuel moisture and reducing fuel amount and continuity: International Journal of Wildland Fire, v. 24, no. 6, p. 849–856. Davies, K.W., Boyd, C.S., Bates, J.D., and Hulet, A., 2015b, Winter grazing can reduce wildfire size, intensity and behaviour in a shrub-grassland: International Journal of Wildland Fire, v. 25, no. 2, p. 191–199. Davies, K.W., Boyd, C.S., Bates, J.D., and Hulet, A., 2016b, Winter grazing decreases the probability of fire-induced mortality of bunchgrasses and may reduce wildfire size—A response to Smith et al. (this issue): International Journal of Wildland Fire, v. 25, no. 4, p. 489–493.

Appendix 1. Literature Included in Scoring Next Steps for the Invasives Topic in the Actionable Science Plan   27 Davies, K.W., Gearhart, A., Boyd, C.S., and Bates, J.D., 2017, Fall and spring grazing influence fire ignitability and initial spread in shrub steppe communities: International Journal of Wildland Fire, v. 26, no. no. 6, p. 485–490.

Hunter, H.E., Husby, P.O., Fidel, J., and Mosley, J.C., 2018, Ecological health of grasslands and sagebrush steppe on the northern Yellowstone Range: Rangelands, v. 40, no. 6, p. 212–223.

Davies, K.W., Nafus, A.M., Boyd, C.S., Hulet, A., and Bates, J.D., 2016c, Effects of using winter grazing as a fuel treatment on Wyoming big sagebrush plant communities: Rangeland Ecology and Management, v. 69, no. 3, p. 179–184.

Rowland, M.M., 2019, The effects of management practices on grassland birds—Greater sage-grouse (Centrocercus urophasianus): chap. B of Johnson, D.H., Igl, L.D., Shaffer, J.A., and DeLong, J.P., eds., The effects of management practices on grassland birds, U.S. Geological Survey Professional Paper 1842, 50 p.

Smith, M.S.A., Talhelm, A.F., Kolden, C.A., Newingham, B.A., Adams, H.D., Cohen, J.D., Yedinak, K.M., and Kremens, R.L., 2016, The ability of winter grazing to reduce wildfire size and fire-induced plant mortality was not demonstrated—A comment on Davies et al. (2015): International Journal of Wildland Fire, v. 25, no. 4, p. 484–488.

Next Step 4g Evaluate the interactions between the modifications of fine fuels by grazing and sage-grouse nesting and broodrearing success, including measurement of the impacts of grass height on nesting cover and insect availability. Connell, L.C., Scasta, J.D., and Porensky, L.M., 2018, Prairie dogs and wildfires shape vegetation structure in a sagebrush grassland more than does rest from ungulate grazing: Ecosphere, v. 9, no. 8, 19p. Crist, M.R., Chambers, J.C., Phillips, S.L., Prentice, K.L., and Wiechman, L.A., eds., 2019, Science framework for conservation and restoration of the sagebrush biome—Linking the Department of the Interior’s Integrated Rangeland Fire Management Strategy to long-term strategic conservation actions—Part 2. Management applications: Fort Collins, Colorado, U.S. Forest Service, Rocky Mountain Research Station, General Technical Report RMRS-GTR-389, 237 p.

Veblen, K.E., Nehring, K.C., McGlone, C.M., and Ritchie, M.E., 2015, Contrasting effects of different mammalian herbivores on sagebrush plant communities: PLoS ONE, v. 10, no. 2, 19 p. [Also available at https://doi.org/​10.1371/​ journal.pone.0118016.]

Next Step 4h Evaluate the role of livestock in spreading invasive weeds, and explore methods to ameliorate the problem of the spread of invasive weeds. Chuong, J., Huxley, J., Spotswood, E.N., Nichols, L., Mariotte, P., and Suding, K.N., 2016, Cattle as dispersal vectors of invasive and introduced plants in a California annual grassland: Rangeland Ecology and Management, v. 69, no. 1, p. 52–58. Morton, H.L., 2015, Weed and brush control for range improvement: Range Research and Range Problems, v. 3, p. 55–74. Perryman, B.L., Schultz, B.W., Burrows, M., Shenkoru, T., and Wilker, J., 2020, -grazing and grazing-exclusion effects on cheatgrass (Bromus tectorum) seed bank assays in Nevada, United States: Rangeland Ecology and Management, v. 73, no. 3, p. 343–347.

Cutting, K.A., Rotella, J.J., Schroff, S.R., Frisina, M.R., Waxe, J.A., Nunlist, E., and Sowell, B.F., 2019, Maladaptive nestsite selection by a sagebrush dependent species in a grazingmodified landscape: Journal of Environmental Management, v. 236, p. 622–630.

Porensky, L.M., McGee, R., and Pellatz, D.W., 2020, Longterm grazing removal increased invasion and reduced native plant abundance and diversity in a sagebrush grassland: Global Ecology and Conservation, v. 24, 13 p. [Also available at https://doi.org/​10.1016/​j.gecco.2020.e01267.]

Davies, K.W., Nafus, A.M., Boyd, C.S., Hulet, A., and Bates, J.D., 2016, Effects of using winter grazing as a fuel treatment on Wyoming big sagebrush plant communities: Rangeland Ecology and Management, v. 69, no. 3, p. 179–184.

Reisner, M.D., Doescher, P.S., and Pyke, D.A., 2015, Stressgradient hypothesis explains susceptibility to Bromus tectorum invasion and community stability in North America’s semi-arid Artemisia tridentata wyomingensis ecosystems: Journal of Vegetation Science, v. 26, no. 6, p. 1212–1224.

Elwell, S.L., Griswold, T., and Elle, E., 2016, Habitat type plays a greater role than livestock grazing in structuring shrubsteppe plant-pollinator communities: Journal of Insect Conservation, v. 20, no. 3, p. 515–525.

Root, H.T., Miller, J.E.D., and Rosentreter, R., 2020, Grazing disturbance promotes exotic annual grasses by degrading soil biocrust communities; Ecological Applications, v. 30, no. 1, 10 p.

28   Integrated Rangeland Fire Management Strategy Actionable Science Plan Assessment: Invasives, 2015–20 Veblen, K.E., Nehring, K.C., McGlone, C.M., and Ritchie, M.E., 2015, Contrasting effects of different mammalian herbivores on sagebrush plant communities: PLoS ONE, v. 10, no. 2, 19 p. [Also available at https://doi.org/​10.1371/​ journal.pone.0118016.]

Davies, K.W., Boyd, C.S., Bates, J.D., and Hulet, A., 2015, Dormant season grazing may decrease wildfire probability by increasing fuel moisture and reducing fuel amount and continuity: International Journal of Wildland Fire, v. 24, no. 6, p. 849–856.

Williamson, M.A., Fleishman, E., Mac Nally, R.C., Chambers, J.C., Bradley, B.A., Dobkin, D.S., Board, D.I., Fogarty, F.A., Horning, N., Leu, M., and Zillig, M.W., 2020, Fire, livestock grazing, topography, and precipitation affect occurrence and prevalence of cheatgrass (Bromus tectorum) in the central Great Basin, USA: Biological Invasions, v. 22, no. 2, p. 663–680.

Lehnhoff, E.A., Rew, L.J., Mangold, J.M., Seipel, T., and Ragen, D., 2019, Integrated management of cheatgrass (Bromus tectorum) with sheep grazing and herbicide: Agronomy, v. 9, article 315, 21 p. [Also available at https://doi.org/​10.3390/​agronomy9060315.]

Next Step 4i Develop science-based guidance for implementing and assessing effectiveness and resource and economic impacts of targeted grazing projects to manage wildland fuels. Brownsey, P., James, J.J., Barry, S.J., Becchetti, T.A., Davy, J.S., Doran, M.P., Forero, L.C., Harper, J.M., Larsen, R.E., Larson-Proplan, S.R., Zhang, J., and Laca, E.A., 2017, Using phenology to optimize timing of mowing and grazing treatments for medusahead (Taeniatherum caputmedusae): Rangeland Ecology and Management, v. 70, no. 2, p. 210–218.

Next Step 4j Develop management strategies to accomplish costeffective high herbaceous biomass utilization. Silva, L.G., Benedeti, P.D.B., Paula, E.M., Malekjahani, F., Amaral, P.M., Mariz, L.D.S., Shenkoru, T., and Faciola, A.P., 2017, Effects of carbohydrate and nitrogen supplementation on fermentation of cheatgrass (Bromus tectorum) in a dual-flow continuous culture system: Journal of Animal Science, v. 95, no. 3, p. 1335–1344. Stonecipher, C.A., Panter, K.E., and Villalba, J.J., 2016, Effect of protein supplementation on forage utilization by cattle in annual grass-dominated rangelands in the Channeled Scablands of eastern Washington: Journal of Animal Science, v. 94, no. 6, p. 2572–2582. Villalba, J.J., and Burritt, E.A., 2015, Intake of medusahead by sheep—Influence of supplements, silica, and individual animal variation: Invasive Plant Science and Management, v. 8, no. 2, p. 151–159.

Next Step 4k Continue short-term monitoring and research studies in grazing demonstration areas to ensure that management practices are effective and sustainable.

Montes-Sánchez, J.J., Van Miegroet, H., and Villalba, J.J., 2017, Effects of energy supplementation and time on use of medusahead by grazing ewes with their lambs: Rangeland Ecology and Management, v. 70, no. 3, p. 380–387. Porensky, L.M., Perryman, B.L., Williamson, M.A., Madsen, M.D., and Leger, E.A., 2018, Combining active restoration and targeted grazing to establish native plants and reduce fuel loads in invaded ecosystems: Ecology and Evolution, v. 8, no. 24, p. 12533–12546. Rinella, M.J., and Bellows, S.E., 2016, Evidence-targeted grazing benefits to invaded rangelands can increase over extended time frames: Rangeland Ecology and Management, v. 69, no. 3, p. 169–172.

Next Step 4l Evaluate the effects of grazing over large areas on fire intensity and patchiness, and extent of burned area. Davies, K.W., Boyd, C.S., Bates, J.D., and Hulet, A., 2015, Winter grazing can reduce wildfire size, intensity and behaviour in a shrub-grassland: International Journal of Wildland Fire, v. 25, no. 2, p. 191–199. Davies, K.W., Boyd, C.S., Bates, J.D., and Hulet, A., 2016, grazing decreases the probability of fire-induced mortality of bunchgrasses and may reduce wildfire size—A response to Smith et al. (this issue): International Journal of Wildland Fire, v. 25, no. 4, p. 489–493. Davies, K.W., Gearhart, A., Boyd, C.S., and Bates, J.D., 2017, Fall and spring grazing influence fire ignitability and initial spread in shrub steppe communities: International Journal of Wildland Fire, v. 26, no. no. 6, p. 485–490. Smith, M.S.A., Talhelm, A.F., Kolden, C.A., Newingham, B.A., Adams, H.D., Cohen, J.D., Yedinak, K.M., and Kremens, R.L., 2016, The ability of winter grazing to reduce wildfire size and fire-induced plant mortality was not demonstrated—A comment on Davies et al. (2015): International Journal of Wildland Fire, v. 25, no. 4, p. 484–488.

Appendix 1. Literature Included in Scoring Next Steps for the Invasives Topic in the Actionable Science Plan   29

Next Step 4m Determine the ecological impact of “heavy utilization” to accomplish fuel reduction on the wildlife, plant, and soil microbial communities, especially those related to or dependent on native plants. Davies, K.W., Nafus, A.M., Boyd, C.S., Hulet, A., and Bates, J.D., 2016, Effects of using winter grazing as a fuel treatment on Wyoming big sagebrush plant communities: Rangeland Ecology and Management, v. 69, no. 3, p. 179–184.

Next Step 4n Investigate the effects of feral horses and burros, in combination with livestock, and as a single change agent. Davies, K.W., and Boyd, C.S., 2019, Ecological effects of free-roaming horses in North American rangelands: Bioscience, v. 69, no. 7, p. 558–565. King, S.R.B., Schoenecker, K.A., and Manier, D.J., 2019, Potential spread of cheatgrass and other invasive species by feral horses in western Colorado: Rangeland Ecology and Management, v. 72, no. 4, p. 706–710.

Next Step 4o Develop strategies to replace nonnative annual grasses with grazing-tolerant and fire-resilient plant materials, particularly those that support sage-grouse nesting and brood-rearing, in targeted grazing demonstration areas. Aryal, P., and Islam, M.A., 2018, Effect of forage kochia on seedling growth of cheatgrass (Bromus tectorum) and perennial grasses: Invasive Plant Science and Management, v. 11, no. 4, p. 201–207. Barak, R.S., Fant, J.B., Kramer, A.T., and Skogen, K.A., 2015, Assessing the value of potential “native winners” for restoration of cheatgrass-invaded habitat: Western North American Naturalist, v. 75, no. 1, p. 58–69.

Davies, K.W., and Johnson, D.D., 2017, Established perennial vegetation provides high resistance to reinvasion by exotic annual grasses: Rangeland Ecology and Management, v. 70, no. 6, p. 748–754. Davies, K.W., Boyd, C.S., Johnson, D.D., Nafus, A.M., and Madsen, M.D., 2015, Success of seeding native compared with introduced perennial vegetation for revegetating medusahead-invaded sagebrush rangeland: Rangeland Ecology and Management, v. 68, no. 3, p. 224–230. Davies, K.W., Madsen, M.D., and Hulet, A., 2017, Using activated carbon to limit herbicide effects to seeded bunchgrass when revegetating annual grass-invaded rangelands: Rangeland Ecology and Management, v. 70, no. 5, p. 604–608. Gibson, A., Nelson, C.R., and Atwater, D.Z., 2018, Response of bluebunch wheatgrass to invasion—Differences in competitive ability among invader-experienced and invadernaive populations: Functional Ecology, v. 32, no. 7, p. 1857–1866. Harvey, A.J., Simanonok, S.C., Rew, L.J., Prather, T.S., and Mangold, J.M., 2020, Effect of Pseudoroegneria spicata (bluebunch wheatgrass) seeding date on establishment and resistance to invasion by Bromus tectorum (cheatgrass): Ecological Restoration, v. 38, no. 3, p. 145–152. James, J.J., Gornish, E.S., DiTomaso, J.M., Davy, J., Doran, M.P., Becchetti, T., Lile, D., Brownsey, P., and Laca, E.A., 2015, Managing medusahead (Taeniatherum caputmedusae) on rangeland—A meta-analysis of control effects and assessment of stakeholder needs: Rangeland Ecology and Management, v. 68, no. 3, p. 215–223. Leger, E.A., and Baughman, O.W., 2015, What seeds to plant in the Great Basin? comparing traits prioritized in native plant cultivars and releases with those that promote survival in the field: Natural Areas Journal, v. 35, no. 1, p. 54–68. Leger, E.A., and Goergen, E.M., 2017, Invasive Bromus tectorum alters natural selection in arid systems: Journal of Ecology, v. 105, no. 6, p. 1509–1520.

Blank, R.R., Morgan, T., and Allen, F., 2015, Suppression of annual Bromus tectorum by perennial Agropyron cristatum—Roles of soil nitrogen availability and biological soil space: AoB Plants, v. 7, 11 p. [Also available at https://doi.org/​10.1093/​aobpla/​plv006.]

Monaco, T.A., Mangold, J.M., Mealor, B.A., Mealor, R.D., and Brown, C.S., 2017, Downy brome control and impacts on perennial grass abundance—A systematic review spanning 64 years: Rangeland Ecology and Management, v. 70, no. 3, p. 396–404.

Cumberland, C., Jonas, J.L., and Paschke, M.W., 2017, Impact of grasshoppers and an invasive grass on establishment and initial growth of restoration plant species: Restoration Ecology, v. 25, no. 3, p. 385–395.

Mummey, D.L., Herget, M.E., Hufford, K.M., and Shreading, L., 2016, Germination timing and seedling growth of Poa secunda and the invasive grass, Bromus tectorum, in response to temperature—Evaluating biotypes for seedling traits that improve establishment: Ecological Restoration, v. 34, no. 3, p. 200–208.

30   Integrated Rangeland Fire Management Strategy Actionable Science Plan Assessment: Invasives, 2015–20 Phillips, A.J., and Leger, E.A., 2015, Plastic responses of native plant root systems to the presence of an invasive annual grass: American Journal of Botany, v. 102, no. 1, p. 73–84.

Chambers, J.C., Board, D.I., Roundy, B.A., and Weisberg, P.J., 2017, Removal of perennial herbaceous species affects response of Cold Desert shrublands to fire: Journal of Vegetation Science, v. 28, no. 5, p. 975–984.

Pyke, D.A., and Wirth, T.A., 2017a, Compilation of BLM monitoring reports assessing post wildfire seeding of rangelands, 2001–09: U.S. Geological Survey data release. [Also available at https://doi.org/​10.5066/​F7445JPQ.]

Condon, L.A., and Pyke, D.A., 2018, Fire and grazing influence site resistance to Bromus tectorum through their effects on shrub, bunchgrass and biocrust communities in the Great Basin, USA: New York, Ecosystems, v. 21, no. 7, p. 1416–1431.

Pyke, D.A., and Wirth, T.A., 2017b, Compilation of studies assessing post wildfire seeding of rangelands worldwide, 1965–2010: U.S. Geological Survey data release. [Also available at https://doi.org/​10.5066/​F7MW2F9B.] Rinella, M.J., Knudsen, A.D., Jacobs, J.S., and Mangold, J.M., 2020, Seeding causes long-term increases in grass forage production in invaded rangelands: Rangeland Ecology and Management, v. 73, no. 2, p. 329–333. Schantz, M.C., Sheley, R.L., and James, J.J., 2015, Role of propagule pressure and priority effects on seedlings during invasion and restoration of shrub-steppe: Biological Invasions, v. 17, no. 1, p. 73–85. Stonecipher, C.A., Thacker, E., Welch, K.D., Ralphs, M.H., and Monaco, T.A., 2019, Long-term persistence of coolseason grasses planted to suppress broom snakeweed, downy brome, and weedy forbs: Rangeland Ecology and Management, v. 72, no. 2, p. 266–274. Uselman, S.M., Snyder, K.A., Leger, E.A., and Duke, S.E., 2015, Emergence and early survival of early versus late seral species in Great Basin restoration in two different soil types: Applied Vegetation Science, v. 18, no. 4, p. 624–636. Walker, J.T., James, J.J., and Drenovsky, R.E., 2017, Competition from Bromus tectorum removes differences between perennial grasses in N capture and conservation strategies: Plant and Soil, v. 412, no. 1–2, p. 177–188.

Next Step 4p Evaluate the potential role of livestock grazing to reduce fuel loads in mixed shrub and grass vegetation types over long time frames; include type of livestock (cattle versus sheep), pre-grazing condition, seasonal precipitation (amount and timing), and interactions with other treatment methods, including fire, chemical, and mechanical treatments conducted individually or in combinations. Bailey, D.W., Mosley, J.C., Estell, R.E., Cibils, A.F., Horney, M., Hendrickson, J.R., Walker, J.W., Launchbaugh, K.L., and Burritt, E.A., 2019, Synthesis paper—Targeted livestock grazing—Prescription for healthy rangelands: Rangeland Ecology and Management, v. 72, no. 6, p. 865–877.

Davies, K.W., Bates, J.D., Boyd, C.S., and Svejcar, T.J., 2016, Prefire grazing by cattle increases postfire resistance to exotic annual grass (Bromus tectorum) invasion and dominance for decades: Ecology and Evolution, v. 6, no. 10, p. 3356–3366. Perryman, B.L., Schultz, B.W., McAdoo, J.K., Alverts, R.L., Cervantes, J.C., Foster, S., McCuin, G., and Swanson, S., 2018, Viewpoint—An alternative management paradigm for plant communities affected by invasive annual grass in the Intermountain West: Rangelands, v. 40, no. 3, p. 77–82.

Studies Related to Need 4, but Not Any of the Next Steps NA.

Invasives Need 5 Conduct detailed optimization studies on production and delivery systems of biocontrol agents, followed by evaluation in scaled-up field inoculation trials.

Next Step 5a Develop a study design and protocols that can be used in a U.S. Department of the Interior (DOI) pilot study to ensure consistency in site selection, product application, data collection, and data management to evaluate efficacy and impacts to non-target species across a broad geographical area. NA.

Next Step 5b Develop and conduct improved trials of the effectiveness and effects of ACK55 to address requirements for EPA registration. Kennedy, A.C., 2018, Selective soil bacteria to manage downy brome, jointed goatgrass, and medusahead and do no harm to other biota: Biological Control, v. 123, p. 18–27.

Appendix 1. Literature Included in Scoring Next Steps for the Invasives Topic in the Actionable Science Plan   31 Reinhart, K.O., Carlson, C.H., Feris, K.P., Germino, M.J., Jandreau, C.J., Lazarus, B.E., Mangold, J., Pellatz, D.W., Ramsey, P., Rinella, M.J., and Valliant, M., 2020, Weedsuppressive bacteria fail to control Bromus tectorum under field conditions: Rangeland Ecology and Management, v. 73, no. 6, p. 760–765.

Germino, M.J., and Lazarus, B.E., 2020a, Synthesis of weedsuppressive bacteria studies in rangelands of the western United States—Special section of articles in Rangeland Ecology and Management provides little evidence of effectiveness: Rangeland Ecology and Management, v. 73, no. 6, p. 737–740.

Next Step 5c

Harding, D.P., and Raizada, M.N., 2015, Controlling weeds with fungi, bacteria and viruses—A review: Frontiers in Plant Science, v. 6, 14 p. [Also available at https://doi.org/​ 10.3389/​fpls.2015.00659.]

Evaluate the effectiveness of weed-suppressive bacteria treatments through time to reduce cheatgrass dominance over large areas. Germino, M.J., and Lazarus, B.E., 2020b, Weed-suppressive bacteria have no effect on exotic or native plants in sagebrush-steppe: Rangeland Ecology and Management, v. 73, no. 6, p. 756–759. Kennedy, A.C., 2018, Selective soil bacteria to manage downy brome, jointed goatgrass, and medusahead and do no harm to other biota: Biological Control, v. 123, p. 18–27. Lazarus, B.E., Germino, M.J., Brabec, M., Peterson, L., Walker, R.N., and Moser, A., 2020, Post-fire managementscale trials of bacterial soil amendment MB906 show inconsistent control of invasive annual grasses: Rangeland Ecology and Management, v. 73, no. 6, p. 741–748. Prevéy, J.S., and Seastedt, T.R., 2015, Increased winter precipitation benefits the native plant pathogen Ustilago bullata that infects an invasive grass: Biological Invasions, v. 17, no. 10, p. 3041–3047. Pyke, D.A., Shaff, S.E., Gregg, M.A., and Conley, J.L., 2020, Weed-suppressive bacteria applied as a spray or seed mixture did not control Bromus tectorum: Rangeland Ecology and Management, v. 73, no. 6, p. 749–752. Reinhart, K.O., Carlson, C.H., Feris, K.P., Germino, M.J., Jandreau, C.J., Lazarus, B.E., Mangold, J., Pellatz, D.W., Ramsey, P., Rinella, M.J., and Valliant, M., 2020, Weedsuppressive bacteria fail to control Bromus tectorum under field conditions: Rangeland Ecology and Management, v. 73, no. 6, p. 760–765. Tekiela, D.R., 2020, Effects of the bioherbicide pseudomonas fluorescens D7 on downy brome: Rangeland Ecology and Management, v. 73, no. 6, p. 753–755.

Next Step 5d Complete a review of all open-source and non-opensource literature highlighting successful and unsuccessful applications of weed-suppressive bacteria as a nonnative annual grass biopesticide.

Next Step 5e Develop a user-friendly centralized data management system to promote the exchange of information and facilitate investigation of efficacy and non-target effects of weedsuppressive bacteria. NA.

Next Step 5f Investigate effects of biocontrol agents on soil microbial communities. NA.

Next Step 5g Research and develop new delivery mechanisms (for example, pellets, granules) that will foster successful bacteria application over large areas. NA.

Next Step 5h Develop best management practices and associated guidance for proper use of biocontrols. NA.

Studies Related to Need 5, but Not Any of the Next Steps Cristofaro, M., Roselli, G., Marini, F., de Lillo, E., Petanovic, R.U., Augé, M., and Rector, B.G., 2020, Open field evaluation of Aculodes altamurgensis, a recently described eriophyid species associated with medusahead (Taeniatherum caput-medusae): Biocontrol Science and Technology, v. 30, no. 4, p. 339–350.

32   Integrated Rangeland Fire Management Strategy Actionable Science Plan Assessment: Invasives, 2015–20 Lozano-Juste, J., Masi, M., Cimmino, A., Clement, S., Fernandez, M.A., Antoni, R., Meyer, S., Rodriguez, P.L., and Evidente, A., 2019, The fungal sesquiterpenoid pyrenophoric acid B uses the plant ABA biosynthetic pathway to inhibit seed germination: Journal of Experimental Botany, v. 70, no. 19, p. 5487–5494.

Invasives Need 6 Investigate cheatgrass die-off and potential biocontrols for cheatgrass to provide effective tools for site preparation.

Next Step 6a Expand analysis of die-offs to include large expanses of cheatgrass-dominated desert valleys across the Great Basin, and use geospatial statistical tools to improve die-off predictive models. Boyte, S.P., Wylie, B.K., and Major, D.J., 2015, Mapping and monitoring cheatgrass dieoff in rangelands of the northern Great Basin USA: Rangeland Ecology and Management, v. 68, no. 1, p. 18–28. Weisberg, P.J., Dilts, T.E., Baughman, O.W., Meyer, S.E., Leger, E.A., Van Gunst, K.J., and Cleeves, L., 2017, Development of remote sensing indicators for mapping episodic die-off of an invasive annual grass (Bromus tectorum) from the Landsat archive: Ecological Indicators, v. 79, p. 173–181.

Next Step 6b

Beckstead, J., Meyer, S.E., Ishizuka, T.S., McEvoy, K.M., and Coleman, C.E., 2016, Lack of host specialization on winter annual grasses in the fungal seed bank pathogen Pyrenophora semeniperda: PLoS ONE, v. 11, no. 3, 20 p. [Also available at https://doi.org/​10.1371/​ journal.pone.0151058.] Coleman, C.E., Meyer, S.E., and Ricks, N., 2019, Mating system complexity and cryptic speciation in the seed bank pathogen Pyrenophora semeniperda: Plant Pathology, v. 68, no. 2, p. 369–382. Connolly, B.M., Carris, L.M., and Mack, R.N., 2018, Soilborne seed pathogens—Contributors to the naturalization gauntlet in Pacific Northwest (USA) forest and steppe communities?: Plant Ecology, v. 219, no. 4, p. 359–368. Ehlert, K.A., Miller, Z., Mangold, J.M., Menalled, F., and Thornton, A., 2019, Temperature effects on three downy brome (Bromus tectorum) seed collections inoculated with the fungal pathogen Pyrenophora semeniperda: Invasive Plant Science and Management, v. 12, no. 2, p. 150–154. Masi, M., Meyer, S., Pescitelli, G., Cimmino, A., Clement, S., Peacock, B., and Evidente, A., 2017, Phytotoxic activity against Bromus tectorum for secondary metabolites of a seed-pathogenic Fusarium strain belonging to the F. tricinctum species complex: Natural Product Research, v. 31, no. 23, p. 2768–2777.

Next Step 6d Determine the effects of cheatgrass pathogens on nontarget hosts, including species likely to be included in restoration seeding mixes.

Develop technology to measure pathogen loads in soil using molecular-genetic techniques. NA.

Baughman, O.W., Burton, R., Williams, M., Weisberg, P.J., Dilts, T.E., and Leger, E.A., 2017, Cheatgrass die-offs—A unique restoration opportunity in northern Nevada: Rangelands, v. 39, no. 6, p. 165–173.

Next Step 6c

Baughman, O.W., Meyer, S.E., Aanderud, Z.T., and Leger, E.A., 2016, Cheatgrass die-offs as an opportunity for restoration in the Great Basin, USA—Will local or commercial native plants succeed where exotic invaders fail?: Journal of Arid Environments, v. 124, p. 193–204.

Carry out studies on small plots where pathogen load and environmental conditions are manipulated to determine how and where failure of cheatgrass can be induced by management as a site-preparation technique prior to restoration seeding. Allen, P.S., Finch-Boekweg, H., and Meyer, S.E., 2018, A proposed mechanism for high pathogen-caused mortality in the seed bank of an invasive annual grass: Fungal Ecology, v. 35, p. 108–115.

Ehlert, K.A., Mangold, J.M., Menalled, F., Miller, Z., and Dyer, A., 2019, Seeding, herbicide, and fungicide impact on perennial grass establishment in cheatgrass infested habitats: Ecological Restoration, v. 37, no. 2, p. 67–70.

Appendix 1. Literature Included in Scoring Next Steps for the Invasives Topic in the Actionable Science Plan   33

Next Step 6e

Next Step 6h

Continue and expand studies to assess effectiveness of restoration seedings in new die-offs (mapped in real-time), including reestablishment of deep-rooted perennial grasses and sagebrush.

Develop technology to scale up inoculum production for promising strains of potential biocontrol organisms. NA.

Baughman, O.W., Burton, R., Williams, M., Weisberg, P.J., Dilts, T.E., and Leger, E.A., 2017, Cheatgrass die-offs—A unique restoration opportunity in northern Nevada: Rangelands, v. 39, no. 6, p. 165–173.

Studies Related to Need 6, but Not Any of the Next Steps

Baughman, O.W., Meyer, S.E., Aanderud, Z.T., and Leger, E.A., 2016, Cheatgrass die-offs as an opportunity for restoration in the Great Basin, USA—Will local or commercial native plants succeed where exotic invaders fail?: Journal of Arid Environments, v. 124, p. 193–204.

Next Step 6f Use die-off predictive models and information about seed-bed pathogen loads to determine where to install study trials over large areas to evaluate induced die-offs with and without inoculum additions. NA.

Next Step 6g Carry out die-off induction trials over large geographic areas, and include post-die-off restoration seeding (using appropriate native plant materials) to determine how well this type of site preparation facilitates the establishment of seeded species across a range of site types in different environments. Baughman, O.W., Burton, R., Williams, M., Weisberg, P.J., Dilts, T.E., and Leger, E.A., 2017, Cheatgrass die-offs—A unique restoration opportunity in northern Nevada: Rangelands, v. 39, no. 6, p. 165–173. Baughman, O.W., Meyer, S.E., Aanderud, Z.T., and Leger, E.A., 2016, Cheatgrass die-offs as an opportunity for restoration in the Great Basin, USA—Will local or commercial native plants succeed where exotic invaders fail?: Journal of Arid Environments, v. 124, p. 193–204.

Gehring, C.A., Hayer, M., Flores-Renteria, L., Krohn, A.F., Schwartz, E., and Dijkstra, P., 2016, Cheatgrass invasion alters the abundance and composition of dark septate fungal communities in sagebrush steppe: Botany, v. 94, no. 6, p. 481–491. Masi, M., Meyer, S., Gorecki, M., Pescitelli, G., Clement, S., Cimmino, A., and Evidente, A., 2018, Phytotoxic activity of metabolites isolated from Rutstroemia sp.n., the causal agent of Bleach Blonde Syndrome on cheatgrass (Bromus tectorum): Molecules, v. 23, article 1734, 12 p. Meyer, S.E., Beckstead, J., and Allen, P.S., 2018, Niche specialization in Bromus tectorum seed bank pathogens: Seed Science Research, v. 28, no. 3, p. 215–221. Meyer, S.E., Beckstead, J., and Pearce, J., 2016, Community ecology of fungal pathogens on Bromus tectorum, in Germino, M.J., Chambers, J.C., and Brown, C.S., eds., Exotic brome-grasses in arid and semiarid ecosystems of the western U.S: Switzerland, Springer International Publishing, p. 193–223. Ricks, K.D., and Koide, R.T., 2019, Biotic filtering of endophytic fungal communities in Bromus tectorum: Oecologia, v. 189, no. 4, p. 993–1003. Salo, C., 2018, Army cutworm outbreak produced cheatgrass die-offs and defoliated shrubs in southwest Idaho in 2014: Rangelands, v. 40, no. 4, p. 99–105. Smull, D.M., Pendleton, N., Kleinhesselink, A.R., and Adler, P.B., 2019, Climate change, snow mold and the Bromus tectorum invasion—Mixed evidence for release from cold weather pathogens: AoB Plants, v. 11, no. 5, 9 p.

For information about the research in this report, contact Director, Forest and Rangeland Ecosystem Science Center 777 NW 9th Street Suite 400 Corvallis, OR 97330 h​ttps://www​.usgs.gov/​centers/​forest-​and-​rangeland-​ecosystem-​ science-​center Manuscript approved on January 19, 2023 Publishing support provided by the U.S. Geological Survey Science Publishing Network, Tacoma Publishing Service Center

Anthony and others—Integrated Rangeland Fire Management Strategy Actionable Science Plan Assessment: Invasives, 2015–20—OFR 2023–1003

ISSN 2331-1258 (online) https://doi.org/​10.3133/​ofr20231003

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