Through their dam-building activities and subsequent water storage, beaver have the potential to ... more Through their dam-building activities and subsequent water storage, beaver have the potential to restore riparian ecosystems and offset some of the predicted effects of climate change by modulating streamflow. Thus, it is not surprising that reintroducing beaver to watersheds from which they have been extirpated is an often-used restoration and climate-adaptation strategy. Identifying sites for reintroduction, however, requires detailed information about habitat factors-information that is not often available at broad spatial scales. Here we explore the potential for beaver relocation throughout the Snohomish River Basin in Washington, USA with a model that identifies some of the basic building blocks of beaver habitat suitability and does so by relying solely on remotely sensed data. More specifically, we developed a generalized intrinsic potential model that draws on remotely sensed measures of stream gradient, stream width, and valley width to identify where beaver could become e...
Conservation biology : the journal of the Society for Conservation Biology, 2015
Most conservation planning to date has focused on protecting today's biodiversity with the as... more Most conservation planning to date has focused on protecting today's biodiversity with the assumption that it will be tomorrow's biodiversity. However, modern climate change has already resulted in distributional shifts of some species and is projected to result in many more shifts in the coming decades. As species redistribute and biotic communities reorganize, conservation plans based on current patterns of biodiversity may fail to adequately protect species in the future. One approach for addressing this issue is to focus on conserving a range of abiotic conditions in the conservation-planning process. By doing so, it may be possible to conserve an abiotically diverse "stage" upon which evolution will play out and support many actors (biodiversity). We reviewed the fundamental underpinnings of the concept of conserving the abiotic stage, starting with the early observations of von Humboldt, who mapped the concordance of abiotic conditions and vegetation, and pro...
Background/Question/Methods Land-use change due to human population and economic growth has been ... more Background/Question/Methods Land-use change due to human population and economic growth has been one of the major drivers of environmental change over the last 100 years. As a result native habitats have been reduced and fragmented, causing a loss of biodiversity and ecosystem services. Evaluating how alternative policies can affect the trajectory of land-use change in the conterminous U.S.A., and estimating the resulting changes in terrestrial carbon storage and habitat of native vertebrates, will provide information useful for decision-makers. Our approach started with econometric models based on observed landowner behavior that predict likely land-use changes as a function of current land-use conditions, public policy and market opportunities. Land market dynamics were incorporated into the modeling approach to reflect supply and demand of land in various uses, thereby capturing land-market feedback effects that have been largely ignored to date in the conservation literature. Pr...
Over the next century, climate change will transform California's ecosystems. In 2012, the Re... more Over the next century, climate change will transform California's ecosystems. In 2012, the Resources Legacy Fund convened an expert panel to help translate current scientific understanding of climate change and its potential impacts into actionable knowledge that can be used today by natural resource planners, managers, regulators, and others. The result was a set of nine Guiding Principles that focus on ways to sustain the conditions and processes that will help ensure the persistence of diverse and well-functioning ecosystems and their delivery of benefits to society, even as California's species move and ecological systems transform.
Background/Question/Methods As climate changes, populations must navigate a complicated, human-al... more Background/Question/Methods As climate changes, populations must navigate a complicated, human-altered landscape to track their preferred climate. As a result, their paths may frequently be cut off by roads and cities or by intervening inhospitable climates, leading to dead ends and potentially, extirpations. To conserve future biodiversity, we will likely need to facilitate efficient climate tracking. We use a new approach for identifying corridors for facilitating climate-driven movements to create a climate-corridor map for the United States. We identify a vast network of corridors that connect warmer to cooler patches of natural land cover by following shallow temperature gradients while avoiding areas of high human impact. We then assess how far an organism living in a given patch could move through the network to track climate gradients. We evaluate the relative importance of climate gradients versus human impact for identifying connectivity in different regions of the US. Res...
Background/Question/Methods Wildlife managers must identify stressors that threaten persistence o... more Background/Question/Methods Wildlife managers must identify stressors that threaten persistence of populations and then try to reduce risk posed to population viability. Experimental field research provides clear evidence connecting management actions to outcomes. However, field research can be challenging when working with species of conservation concern, due to permitting issues and fear of doing harm to endangered populations, sampling issues and lack of statistical power, or time limitations when a population is rapidly decreasing or decisions regarding protection status are pending. Scenario modeling can be used within an ecological risk assessment framework to assess threats to species populations and their habitats while avoiding issues encountered with experimental field research and to examine potential tradeoffs associated with alternative management actions. We used an approach combining scenario planning and ecological risk assessment to map and quantify risk to populati...
ABSTRACT Background/Question/Methods Reserves help maintain biodiversity by providing fixed areas... more ABSTRACT Background/Question/Methods Reserves help maintain biodiversity by providing fixed areas of protected land that offer species refuge from anthropogenic threats such as habitat loss. Climate change is expected to cause shifts in species distributions resulting in changes in the flora and fauna of reserves. Dynamic range shifts over static reserve boundaries may cause some species to lose protection as they migrate out of reserves. Due to the northern spatial bias of current reserve networks, reserves are likely to experience higher levels of climatic changes compared to the global average, thus exacerbating the threat of climate change to currently protected biodiversity. Here, we assess the potential magnitude of climate-driven changes in mammalian diversity in the existing reserve network of North and South America. We used projected-future ranges of 525 mammals generated by existing bioclimatic models to determine future potential-species distributions in the face of climate change. To improve bioclimatic model projections, we limited modeled range-shifts to species-specific dispersal abilities. The dispersal models incorporated body mass, diet type, and the period of time between successive generations to investigate the potential for species to track changes in their climatic niches. Results/Conclusions We assessed the overall mammalian-turnover in the reserve network as well as projected changes to specific groups of reserves. Preliminary results for some of the larger reserves in the United States indicate potential turnover in vertebrate fauna ranging from 8% to 61% depending on the location of the reserve.
ABSTRACT Background/Question/Methods In the past, as climates changed, many species moved thousan... more ABSTRACT Background/Question/Methods In the past, as climates changed, many species moved thousands of kilometers to track suitable climates. Species movements in response to projected future climatic changes will be far more restricted due to the human presence on the landscape. Several recent studies have projected potential future shifts in species distributions in response to climate change. These projections indicate the potential for large shifts in species distributions and large changes in local biodiversity. Although these projections provide a good first approximation of the nature of potential range shifts and the magnitude or spatial distribution of potential changes in biodiversity, the uncertainties in these projections bring their utility for conservation planning and for addressing connectivity into question. Here, we explore one way in which projected range shifts and projected changes in climate could be used for identifying areas that are important for connectivity in a changing climate. Specifically, we use projected range shifts for 2954 vertebrate species to assess, for any given place in the western hemisphere, the general direction that species are likely to move in response to climate change. We demonstrate how these movement vectors can be used in conjunction with other data sources to prioritize areas to promote connectivity in a changing climate. Results/Conclusions In the western hemisphere, some of the largest projected climate-driven changes in vertebrate faunas are in western South America and the far northern latitudes. In these regions, some areas are projected to experience over 90% turnover in vertebrate species. Not surprisingly, much of the movement in these regions is projected to be to higher elevations and northward, respectively. However, projected movement patterns are less consistent in other parts of the hemisphere. When overlaid with land-use data, the data on potential species movements provide additional tools for planning for connectivity in a changing climate.
ABSTRACT Background/Question/Methods Conservation planning has traditionally focused on proportio... more ABSTRACT Background/Question/Methods Conservation planning has traditionally focused on proportional representation of regional biodiversity. However, the distribution and composition of biodiversity in a region may change in a changing climate, so biodiversity-based conservation planning may be less effective in the future. Abiotic diversity—e.g., variability in topography, soil types, and climate —can function as a surrogate for biotic diversity, and conserving the abiotic variability of a landscape may create a reserve network that is more robust to climate change. Including abiotic variability in conservation planning also reduces sampling biases inherent in biodiversity data and allows for flexibility in reserve selection subject to practitioners’ objectives. Conservation planning with abiotic facets has been suggested as a climate adaptation strategy, but has not been implemented, and tradeoffs with traditional biodiversity-based planning have not been explored. We use Marxan, a reserve selection software, to compare conservation plans based on both abiotic facets and biodiversity targets in the Columbia Plateau ecoregion. We prioritize sites to create a portfolio of reserves that conserve the regional diversity of sets of abiotic facets; we compare these results to reserves selected with traditional biodiversity targets; and we assess tradeoffs between the two approaches. Results/Conclusions Correspondence analyses between clustered sets of abiotic facets and vegetation cover were highly significant (χ2 ≥ 1669000, P < 0.001), indicating that abiotic facets and vegetation types were strongly correlated. However, targeting abiotic diversity instead of biotic diversity resulted in different spatial distributions of priority sites. Our biodiversity-based selection scenario consisted of targets for both vegetation types and rare species. The most efficient set of reserves based on abiotic facets represented 76% of the vegetation type targets but only 16% of the rare species targets. Thus abiotic facets were useful surrogates for vegetation types but inadequate surrogates for rare species. We recommend that conservation planners prioritize sites that are dually necessary to achieve conservation goals for both abiotic facets and current biodiversity.
Through their dam-building activities and subsequent water storage, beaver have the potential to ... more Through their dam-building activities and subsequent water storage, beaver have the potential to restore riparian ecosystems and offset some of the predicted effects of climate change by modulating streamflow. Thus, it is not surprising that reintroducing beaver to watersheds from which they have been extirpated is an often-used restoration and climate-adaptation strategy. Identifying sites for reintroduction, however, requires detailed information about habitat factors-information that is not often available at broad spatial scales. Here we explore the potential for beaver relocation throughout the Snohomish River Basin in Washington, USA with a model that identifies some of the basic building blocks of beaver habitat suitability and does so by relying solely on remotely sensed data. More specifically, we developed a generalized intrinsic potential model that draws on remotely sensed measures of stream gradient, stream width, and valley width to identify where beaver could become e...
Conservation biology : the journal of the Society for Conservation Biology, 2015
Most conservation planning to date has focused on protecting today's biodiversity with the as... more Most conservation planning to date has focused on protecting today's biodiversity with the assumption that it will be tomorrow's biodiversity. However, modern climate change has already resulted in distributional shifts of some species and is projected to result in many more shifts in the coming decades. As species redistribute and biotic communities reorganize, conservation plans based on current patterns of biodiversity may fail to adequately protect species in the future. One approach for addressing this issue is to focus on conserving a range of abiotic conditions in the conservation-planning process. By doing so, it may be possible to conserve an abiotically diverse "stage" upon which evolution will play out and support many actors (biodiversity). We reviewed the fundamental underpinnings of the concept of conserving the abiotic stage, starting with the early observations of von Humboldt, who mapped the concordance of abiotic conditions and vegetation, and pro...
Background/Question/Methods Land-use change due to human population and economic growth has been ... more Background/Question/Methods Land-use change due to human population and economic growth has been one of the major drivers of environmental change over the last 100 years. As a result native habitats have been reduced and fragmented, causing a loss of biodiversity and ecosystem services. Evaluating how alternative policies can affect the trajectory of land-use change in the conterminous U.S.A., and estimating the resulting changes in terrestrial carbon storage and habitat of native vertebrates, will provide information useful for decision-makers. Our approach started with econometric models based on observed landowner behavior that predict likely land-use changes as a function of current land-use conditions, public policy and market opportunities. Land market dynamics were incorporated into the modeling approach to reflect supply and demand of land in various uses, thereby capturing land-market feedback effects that have been largely ignored to date in the conservation literature. Pr...
Over the next century, climate change will transform California's ecosystems. In 2012, the Re... more Over the next century, climate change will transform California's ecosystems. In 2012, the Resources Legacy Fund convened an expert panel to help translate current scientific understanding of climate change and its potential impacts into actionable knowledge that can be used today by natural resource planners, managers, regulators, and others. The result was a set of nine Guiding Principles that focus on ways to sustain the conditions and processes that will help ensure the persistence of diverse and well-functioning ecosystems and their delivery of benefits to society, even as California's species move and ecological systems transform.
Background/Question/Methods As climate changes, populations must navigate a complicated, human-al... more Background/Question/Methods As climate changes, populations must navigate a complicated, human-altered landscape to track their preferred climate. As a result, their paths may frequently be cut off by roads and cities or by intervening inhospitable climates, leading to dead ends and potentially, extirpations. To conserve future biodiversity, we will likely need to facilitate efficient climate tracking. We use a new approach for identifying corridors for facilitating climate-driven movements to create a climate-corridor map for the United States. We identify a vast network of corridors that connect warmer to cooler patches of natural land cover by following shallow temperature gradients while avoiding areas of high human impact. We then assess how far an organism living in a given patch could move through the network to track climate gradients. We evaluate the relative importance of climate gradients versus human impact for identifying connectivity in different regions of the US. Res...
Background/Question/Methods Wildlife managers must identify stressors that threaten persistence o... more Background/Question/Methods Wildlife managers must identify stressors that threaten persistence of populations and then try to reduce risk posed to population viability. Experimental field research provides clear evidence connecting management actions to outcomes. However, field research can be challenging when working with species of conservation concern, due to permitting issues and fear of doing harm to endangered populations, sampling issues and lack of statistical power, or time limitations when a population is rapidly decreasing or decisions regarding protection status are pending. Scenario modeling can be used within an ecological risk assessment framework to assess threats to species populations and their habitats while avoiding issues encountered with experimental field research and to examine potential tradeoffs associated with alternative management actions. We used an approach combining scenario planning and ecological risk assessment to map and quantify risk to populati...
ABSTRACT Background/Question/Methods Reserves help maintain biodiversity by providing fixed areas... more ABSTRACT Background/Question/Methods Reserves help maintain biodiversity by providing fixed areas of protected land that offer species refuge from anthropogenic threats such as habitat loss. Climate change is expected to cause shifts in species distributions resulting in changes in the flora and fauna of reserves. Dynamic range shifts over static reserve boundaries may cause some species to lose protection as they migrate out of reserves. Due to the northern spatial bias of current reserve networks, reserves are likely to experience higher levels of climatic changes compared to the global average, thus exacerbating the threat of climate change to currently protected biodiversity. Here, we assess the potential magnitude of climate-driven changes in mammalian diversity in the existing reserve network of North and South America. We used projected-future ranges of 525 mammals generated by existing bioclimatic models to determine future potential-species distributions in the face of climate change. To improve bioclimatic model projections, we limited modeled range-shifts to species-specific dispersal abilities. The dispersal models incorporated body mass, diet type, and the period of time between successive generations to investigate the potential for species to track changes in their climatic niches. Results/Conclusions We assessed the overall mammalian-turnover in the reserve network as well as projected changes to specific groups of reserves. Preliminary results for some of the larger reserves in the United States indicate potential turnover in vertebrate fauna ranging from 8% to 61% depending on the location of the reserve.
ABSTRACT Background/Question/Methods In the past, as climates changed, many species moved thousan... more ABSTRACT Background/Question/Methods In the past, as climates changed, many species moved thousands of kilometers to track suitable climates. Species movements in response to projected future climatic changes will be far more restricted due to the human presence on the landscape. Several recent studies have projected potential future shifts in species distributions in response to climate change. These projections indicate the potential for large shifts in species distributions and large changes in local biodiversity. Although these projections provide a good first approximation of the nature of potential range shifts and the magnitude or spatial distribution of potential changes in biodiversity, the uncertainties in these projections bring their utility for conservation planning and for addressing connectivity into question. Here, we explore one way in which projected range shifts and projected changes in climate could be used for identifying areas that are important for connectivity in a changing climate. Specifically, we use projected range shifts for 2954 vertebrate species to assess, for any given place in the western hemisphere, the general direction that species are likely to move in response to climate change. We demonstrate how these movement vectors can be used in conjunction with other data sources to prioritize areas to promote connectivity in a changing climate. Results/Conclusions In the western hemisphere, some of the largest projected climate-driven changes in vertebrate faunas are in western South America and the far northern latitudes. In these regions, some areas are projected to experience over 90% turnover in vertebrate species. Not surprisingly, much of the movement in these regions is projected to be to higher elevations and northward, respectively. However, projected movement patterns are less consistent in other parts of the hemisphere. When overlaid with land-use data, the data on potential species movements provide additional tools for planning for connectivity in a changing climate.
ABSTRACT Background/Question/Methods Conservation planning has traditionally focused on proportio... more ABSTRACT Background/Question/Methods Conservation planning has traditionally focused on proportional representation of regional biodiversity. However, the distribution and composition of biodiversity in a region may change in a changing climate, so biodiversity-based conservation planning may be less effective in the future. Abiotic diversity—e.g., variability in topography, soil types, and climate —can function as a surrogate for biotic diversity, and conserving the abiotic variability of a landscape may create a reserve network that is more robust to climate change. Including abiotic variability in conservation planning also reduces sampling biases inherent in biodiversity data and allows for flexibility in reserve selection subject to practitioners’ objectives. Conservation planning with abiotic facets has been suggested as a climate adaptation strategy, but has not been implemented, and tradeoffs with traditional biodiversity-based planning have not been explored. We use Marxan, a reserve selection software, to compare conservation plans based on both abiotic facets and biodiversity targets in the Columbia Plateau ecoregion. We prioritize sites to create a portfolio of reserves that conserve the regional diversity of sets of abiotic facets; we compare these results to reserves selected with traditional biodiversity targets; and we assess tradeoffs between the two approaches. Results/Conclusions Correspondence analyses between clustered sets of abiotic facets and vegetation cover were highly significant (χ2 ≥ 1669000, P < 0.001), indicating that abiotic facets and vegetation types were strongly correlated. However, targeting abiotic diversity instead of biotic diversity resulted in different spatial distributions of priority sites. Our biodiversity-based selection scenario consisted of targets for both vegetation types and rare species. The most efficient set of reserves based on abiotic facets represented 76% of the vegetation type targets but only 16% of the rare species targets. Thus abiotic facets were useful surrogates for vegetation types but inadequate surrogates for rare species. We recommend that conservation planners prioritize sites that are dually necessary to achieve conservation goals for both abiotic facets and current biodiversity.
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Papers by Joshua Lawler