8 research outputs found

    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 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 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 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

    THE RATE OF BINARY BLACK HOLE MERGERS INFERRED FROM ADVANCED LIGO OBSERVATIONS SURROUNDING GW150914

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    A transient gravitational-wave signal, GW150914, was identi fi ed in the twin Advanced LIGO detectors on 2015 September 2015 at 09:50:45 UTC. To asse ss the implications of this discovery, the detectors remained in operation with unchanged con fi gurations over a period of 39 days around the time of t he signal. At the detection statistic threshold corresponding to that observed for GW150914, our search of the 16 days of simultaneous two-detector observational data is estimated to have a false-alarm rate ( FAR ) of < ́ -- 4.9 10 yr 61 , yielding a p -value for GW150914 of < ́ - 210 7 . Parameter estimation follo w-up on this trigger identi fi es its source as a binary black hole ( BBH ) merger with component masses ( )( ) = - + - + mm M ,36,29 12 4 5 4 4 at redshift = - + z 0.09 0.04 0.03 ( median and 90% credible range ) . Here, we report on the constraints these observations place on the rate of BBH coalescences. Considering only GW150914, assuming that all BBHs in the universe have the same masses and spins as this event, imposing a search FAR threshold of 1 per 100 years, and assuming that the BBH merger rate is constant in the comoving frame, we infer a 90% credible range of merger rates between – -- 2 53 Gpc yr 31 ( comoving frame ) . Incorporating all search triggers that pass a much lower threshold while accounting for the uncerta inty in the astrophysical origin of each trigger, we estimate a higher rate, ranging from – -- 13 600 Gpc yr 31 depending on assumptions about the BBH mass distribution. All together, our various rate estimat es fall in the conservative range – -- 2 600 Gpc yr 31

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

    Get PDF
    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

    Estimation of the Mortalities of the Immature Stages and Adults

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