37 research outputs found

    Archaeological Landscapes during the 10–8 ka Lake Stanley Lowstand on the Alpena‐Amberley Ridge, Lake Huron

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    Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/136243/1/gea21590.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/136243/2/gea21590_am.pd

    A synthesis of the effects of cheatgrass invasion on the US Great Basin carbon storage

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    Non‐native, invasive Bromus tectorum (cheatgrass) is pervasive in sagebrush ecosystems in the Great Basin ecoregion of the western United States, competing with native plants and promoting more frequent fires. As a result, cheatgrass invasion likely alters carbon (C) storage in the region. Many studies have measured C pools in one or more common vegetation types: native sagebrush, invaded sagebrush and cheatgrass‐dominated (often burned) sites, but these results have yet to be synthesized. We performed a literature review to identify studies assessing the consequences of invasion on C storage in above‐ground biomass (AGB), below‐ground biomass (BGB), litter, organic soil and total soil. We identified 41 articles containing 386 unique studies and estimated C storage across pools and vegetation types. We used linear mixed models to identify the main predictors of C storage. We found consistent declines in biomass C with invasion: AGB C was 55% lower in cheatgrass (40 ± 4 g C/m2) than native sagebrush (89 ± 27 g C/m2) and BGB C was 62% lower in cheatgrass (90 ± 17 g C/m2) than native sagebrush (238 ± 60 g C/m2). In contrast, litter C was \u3e4× higher in cheatgrass (154 ± 12 g C/m2) than native sagebrush (32 ± 12 g C/m2). Soil organic C (SOC) in the top 10 cm was significantly higher in cheatgrass than in native or invaded sagebrush. SOC below 20 cm was significantly related to the time since most recent fire and losses were observed in deep SOC in cheatgrass \u3e5 years after a fire. There were no significant changes in total soil C across vegetation types. Synthesis and applications. Cheatgrass invasion decreases biodiversity and rangeland productivity and alters fire regimes. Our findings indicate cheatgrass invasion also results in persistent biomass carbon (C) losses that occur with sagebrush replacement. We estimate that conversion from native sagebrush to cheatgrass leads to a net reduction of C storage in biomass and litter of 76 g C/m2, or 16 Tg C across the Great Basin without management practices like native sagebrush restoration or cheatgrass removal

    Restoration Handbook for Sagebrush Steppe Ecosystems with Emphasis on Greater Sage-Grouse Habitat—Part 3. Site Level Restoration Decisions

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    Sagebrush steppe ecosystems in the United States currently (2016) occur on only about one-half of their historical land area because of changes in land use, urban growth, and degradation of land, including invasions of non-native plants. The existence of many animal species depends on the existence of sagebrush steppe habitat. The greater sage-grouse (Centrocercus urophasianus) depends on large landscapes of intact habitat of sagebrush and perennial grasses for their existence. In addition, other sagebrush-obligate animals have similar requirements and restoration of landscapes for greater sage-grouse also will benefit these animals. Once sagebrush lands are degraded, they may require restoration actions to make those lands viable habitat for supporting sagebrush-obligate animals, livestock, and wild horses, and to provide ecosystem services for humans now and for future generations. When a decision is made on where restoration treatments should be applied, there are a number of site-specific decisions managers face before selecting the appropriate type of restoration. This site-level decision tool for restoration of sagebrush steppe ecosystems is organized in nine steps. ●Step 1 describes the process of defining site-level restoration objectives. ●Step 2 describes the ecological site characteristics of the restoration site. This covers soil chemistry and texture, soil moisture and temperature regimes, and the vegetation communities the site is capable of supporting. ●Step 3 compares the current vegetation to the plant communities associated with the site State and Transition models. ●Step 4 takes the manager through the process of current land uses and past disturbances that may influence restoration success. ●Step 5 is a brief discussion of how weather before and after treatments may impact restoration success. ●Step 6 addresses restoration treatment types and their potential positive and negative impacts on the ecosystem and on habitats, especially for greater sage-grouse. We discuss when passive restoration options may be sufficient and when active restoration may be necessary to achieve restoration objectives. ●Step 7 addresses decisions regarding post-restoration livestock grazing management. ●Step 8 addresses monitoring of the restoration; we discuss important aspects associated with implementation monitoring as well as effectiveness monitoring. ●Step 9 takes the information learned from monitoring to determine how restoration actions in the future might be adapted to improve restoration success

    Restoration Handbook for Sagebrush Steppe Ecosystems with Emphasis on Greater Sage-Grouse Habitat—Part 1. Concepts for Understanding and Applying Restoration

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    Sagebrush steppe ecosystems in the United States currently occur on only about one-half of their historical land area because of changes in land use, urban growth, and degradation of land, including invasions of non-native plants. The existence of many animal species depends on the existence of sagebrush steppe habitat. The greater sage-grouse (Centrocercus urophasianus) is a landscape-dependent bird that requires intact habitat and combinations of sagebrush and perennial grasses to exist. In addition, other sagebrush-obligate animals also have similar requirements and restoration of landscapes for greater sage-grouse also will benefit these animals. Once sagebrush lands are degraded, they may require restoration actions to make those lands viable habitat for supporting sagebrush-obligate animals. This restoration handbook is the first in a three-part series on restoration of sagebrush ecosystems. In Part 1, we discuss concepts surrounding landscape and restoration ecology of sagebrush ecosystems and greater sage-grouse that habitat managers and restoration practitioners need to know to make informed decisions regarding where and how to restore specific areas. We will describe the plant dynamics of sagebrush steppe ecosystems and their responses to major disturbances, fire, and defoliation. We will introduce the concepts of ecosystem resilience to disturbances and resistance to invasions of annual grasses within sagebrush steppe. An introduction to soils and ecological site information will provide insights into the specific plants that can be restored in a location. Soil temperature and moisture regimes are described as a tool for determining resilience and resistance and the potential for various restoration actions. Greater sage-grouse are considered landscape birds that require large areas of intact sagebrush steppe; therefore, we describe concepts of landscape ecology that aid our decisions regarding habitat restoration. We provide a brief overview of restoration techniques for sage-grouse habitat restoration. We conclude with a description of the critical nature of monitoring for adaptive management of sagebrush steppe restoration at landscape- and project-specific levels

    Restoration Handbook for Sagebrush Steppe Ecosystems with Emphasis on Greater Sage-Grouse Habitat—Part 2. Landscape Level Restoration Decisions

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    Sagebrush steppe ecosystems in the United States currently (2015) occur on only about one-half of their historical land area because of changes in land use, urban growth, and degradation of land, including invasions of non-native plants. The existence of many animal species depends on the existence of sagebrush steppe habitat. The greater sage-grouse (Centrocercus urophasianus) is a landscape-dependent bird that requires intact habitat and combinations of sagebrush and perennial grasses to exist. In addition, other sagebrush-obligate animals also have similar requirements and restoration of landscapes for greater sage-grouse also will benefit these animals. Once sagebrush lands are degraded, they may require restoration actions to make those lands viable habitat for supporting sagebrush-obligate animals. Land managers do not have resources to restore all locations because of the extent of the restoration need and because some land uses are not likely to change, therefore, restoration decisions made at the landscape to regional scale may improve the effectiveness of restoration to achieve landscape and local restoration objectives. We present a landscape restoration decision tool intended to assist decision makers in determining landscape objectives, to identify and prioritize landscape areas where sites for priority restoration projects might be located, and to aid in ultimately selecting restoration sites guided by criteria used to define the landscape objectives. The landscape restoration decision tool is structured in five sections that should be addressed sequentially. Each section has a primary question or statement followed by related questions and statements to assist the user in addressing the primary question or statement. This handbook will guide decision makers through the important process steps of identifying appropriate questions, gathering appropriate data, developing landscape objectives, and prioritizing landscape patches where potential sites for restoration projects may be located. Once potential sites are selected, land managers can move to the site-specific decision tool to guide restoration decisions at the site level

    A Synopsis of Short-Term Response to Alternative Restoration Treatments in Sagebrush-Steppe: The SageSTEP Project

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    The Sagebrush Steppe Treatment Evaluation Project (SageSTEP) is an integrated long-term study that evaluates ecological effects of alternative treatments designed to reduce woody fuels and to stimulate the herbaceous understory of sagebrush steppe communities of the Intermountain West. This synopsis summarizes results through 3 yr posttreatment. Woody vegetation reduction by prescribed fire, mechanical treatments, or herbicides initiated a cascade of effects, beginning with increased availability of nitrogen and soil water, followed by increased growth of herbaceous vegetation. Response of butterflies and magnitudes of runoff and erosion closely followed herbaceous vegetation recovery. Effects on shrubs, biological soil crust, tree cover, surface woody fuel loads, and sagebrush-obligate bird communities will take longer to be fully expressed. In the short term, cool wet sites were more resilient than warm dry sites, and resistance was mostly dependent on pretreatment herbaceous cover. At least 10 yr of posttreatment time will likely be necessary to determine outcomes for most sites. Mechanical treatments did not serve as surrogates for prescribed fire in how each influenced the fuel bed, the soil, erosion, and sage-obligate bird communities. Woody vegetation reduction by any means resulted in increased availability of soil water, higher herbaceous cover, and greater butterfly numbers. We identified several trade-offs (desirable outcomes for some variables, undesirable for others), involving most components of the study system. Trade-offs are inevitable when managing complex natural systems, and they underline the importance of asking questions about the whole system when developing management objectives. Substantial spatial and temporal heterogeneity in sagebrush steppe ecosystems emphasizes the point that there will rarely be a “recipe” for choosing management actions on any specific area. Use of a consistent evaluation process linked to monitoring may be the best chance managers have for arresting woodland expansion and cheatgrass invasion that may accelerate in a future warming climate

    A REGIONAL EXPERIMENT TO EVALUATE EFFECTS OF FIRE AND FIRE SURROGATE TREATMENTS IN THE SAGEBRUSH BIOME

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    SageSTEP is a comprehensive regional experiment that provides critical information to managers faced with a sagebrush steppe ecosystem that is increasingly at risk from wildfire, invasive plants, and climate change. The experiment provides managers with information that can be used to restore ecological communities across the 100+ million acres of the sagebrush biome. It is designed to match the temporal and spatial scales at which managers operate, is intended to reduce management risk and uncertainty of catastrophic wildfire to the greatest degree possible, and provides managers with information that allows them to better understand tradeoffs inherent in the choice of management alternatives. The project has several features that make it ideal for testing hypotheses from state‐andtransition theory, and for discovering information that can be directly applied in a management context ‐‐ it is long‐term, experimental, multisite, multivariate, and treatments are applied across condition gradients, allowing for potential identification of biotic thresholds. The project is designed to distinguish communities that have conditions that will allow them to recover on their own following fuel or restoration treatments, versus communities that have crossed biotic thresholds, and will therefore require more expensive active restoration. SageSTEP is designed as a long‐term study, such that measurements are planned for at least 10 years after treatment implementation, or through the 2018 field season. This final report therefore describes the short‐term effects of treatments, 2‐4 years after treatment implementation., or through the 2010 field season. The Joint Fire Science Program generously funded SageSTEP for its first six years, and this funding was crucial for building an infrastructure that has now set the stage for an unprecedented long‐term study that will provide badly needed information on sagebrush steppe restoration and fuel treatment effectiveness. The infrastructure we’ve built consists of the following eight features: 1. A network of 18 sites distributed across the Great Basin, Snake River Basin, and Columbia Basin, 11 sites in a replicated woodland experiment, and 7 sites in a replicated sage‐cheat experiment (Figure 1). Each site is equivalent to a statistical block consisting of an unmanipulated control, and a set of fire and fire surrogate treatments. 2. A network of weather and soil moisture stations distributed along with the sites, that provides information on inter‐annual and geographic variation in moisture and temperature, and that is being used to interpret patterns of ecological response. 3. A small by efficient staff, consisting of scientists and technicians, responsible for continued monitoring of ecological variables through time, and maintenance of the projects’ infrastructure. 4. A funding stream from several agency sources, with current resources adequate to run the project for at least three more years, and with agreements in place to fund the project through fiscal year 2015. 5. A web of partnerships among managers, scientists, students, stakeholders, and policymakers that has worked together to design the study, implement the treatments, and learn about how sagebrush steppe system respond to alternative restoration treatments. 6. A highly effective and influential outreach program, anchored by a popular website, designed to interpret and deliver scientific information collected by SageSTEP scientists, and to distribute other relevant information originating from outside the project. 7. An on‐line database, called the SageSTEP Data Store, that offers fully proofed and validated data to analysts working within SageSTEP, and which will eventually provide the same information to other interested users. 8. The Great Basin NEON Site, NSF’s atmospheric sampling station that will soon be built at the SageSTEP Onaqui site. This link with NSF provides SageSTEP with leverage for established additional vegetation and soil monitoring facilities at Onaqui. Over the past three years, since post‐treatment data collection commenced, SageSTEP has produced a considerable amount of information, most of it now published in a total of 32 scientific papers. Key outreach products include: ● Active web site (sagestep.org), anchoring a comprehensive outreach program ● User\u27s Guides for Western Juniper & Pinyon‐Juniper woodlands ● Two Fuel Guides, one each for pre‐treatment and post‐treatment conditions ● 15 quarterly newsletters ● Six manager workshops ● 11 tours or field trips ● Three national conference symposia, consisting of 24 papers (2 symposia planned) ● 57 contributed papers at conferences ● Seven Master’s Theses and two Ph.D. Dissertations ● 15 papers published in proceedings or reports ● Ten papers published in peer‐reviewed journals (17 papers currently in review

    Synthesis Paper: Targeted Livestock Grazing: Prescription for Healthy Rangelands

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    Targeted livestock grazing is a proven tool for manipulating rangeland vegetation, and current knowledge about targeted livestock grazing is extensive and expanding rapidly. Targeted grazing prescriptions optimize the timing, frequency, intensity, and selectivity of grazing (or browsing) in combinations that purposely exert grazing/browsing pressure on specific plant species or portions of the landscape. Targeted grazing differs from traditional grazing management in that the goal of targeted grazing is to apply defoliation or trampling to achieve specific vegetation management objectives, whereas the goal of traditional livestock grazing management is generally the production of livestock commodities. A shared aim of targeted livestock grazing and traditional grazing management is to sustain healthy soils, flora, fauna, and water resources that, in turn, can sustain natural ecological processes (e.g., nutrient cycle, water cycle, energy flow). Targeted grazing prescriptions integrate knowledge of plant ecology, livestock nutrition, and livestock foraging behavior. Livestock can be focused on target areas through fencing, herding, or supplement placement. Although practices can be developed to minimize the impact of toxins contained in target plants, the welfare of the animals used in targeted grazing must be a priority. Monitoring is needed to determine if targeted grazing is successful and to refine techniques to improve efficacy and efficiency. Examples of previous research studies and approaches are presented to highlight the ecological benefits that can be achieved when targeted grazing is applied properly. These cases include ways to suppress invasive plants and ways to enhance wildlife habitat and biodiversity. Future research should address the potential to select more adapted and effective livestock for targeted grazing and the associated animal welfare concerns with this practice. Targeted livestock grazing provides land managers a viable alternative to mechanical, chemical, and prescribed fire treatments to manipulate rangeland vegetation

    Climate Change Impacts on Northwestern and Intermountain United States Rangelands

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    The Rangelands archives are made available by the Society for Range Management and the University of Arizona Libraries. Contact [email protected] for further information.Migrated from OJS platform March 202

    EQUIPMENT AND STRATEGIES TO ENHANCE THE POST-WILDFIRE ESTABLISHMENT AND PERSISTENCE OF GREAT BASIN NATIVE PLANTS

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    Annual grass invasion in the Great Basin has increased fire size, frequency and severity. Post-fire restoration to provide functional native plant communities is critical to improve resistance to weed invasion. Our ability to successfully re-establish mixtures of native grasses, forbs and shrubs, however, is limited. We examined the effects of the standard rangeland drill and a minimum-till drill, seeding strategies for small-seeded species, and Wyoming big sagebrush (Artemisia tridentata Nutt. spp. wyomingensis Beetle & Young) seeding rates on seeding success in burned shrub communities at four sites in the northern Great Basin. Seeded and recovering vegetation, as well as soil physical and chemical characteristics, were monitored for two growing seasons following treatment. In addition, provision was made for long-term evaluation of grazed and non-grazed seedings to assess community dynamics in relation to management practices. Results underscore the impact of precipitation and recovering residual species on seeded species emergence and establishment. Emergence of drill seeded species was generally enhanced when seeded through the rangeland drill compared to the minimum-till drill, but this effect was lost by the second year. Wyoming big sagebrush emergence was erratic, but tended to be greater when seeded through the minimum-till drill at moderate or high rates (approximately 250 and 500 pure live seed m-2) compared to the low rate (50 pure live seed m-2). Cheatgrass and other exotics were reduced and basal gap lengths decreased where native seedings established or residual natives recovered, but both increased where seedings failed due to low precipitation. Considerable soil erosion occurred in burned areas, as indicated by dust production, soil stability, and soil microrelief. Fire substantially increased dust flux rates due to decreased soil stability; however, neither drill affected these processes. Amounts of soil movement via dust flux rates and changes in soil microrelief varied throughout seasons but were not affected by drilling. While wildfire altered some soil micronutrients, drilling and seeding rates did not alter chemical responses to fire. Further work is needed to link plant and soil responses, which may help to explain plant establishment after fire and seeding treatments. Vegetation data from this research will be archived in the USGS Land Treatment Digital Library to inform future management and rehabilitation programs
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