This is an open access article under the terms of the Creative Commons Attribution License, which... more This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
Screening is a strategy for detecting undesirable change prior to manifestation of symptoms or ad... more Screening is a strategy for detecting undesirable change prior to manifestation of symptoms or adverse effects. Although the well-recognized utility of screening makes it commonplace in medicine, it has yet to be implemented in ecosystem management. Ecosystem management is in an era of diagnosis and treatment of undesirable change, and as a result, remains more reactive than proactive and unable to effectively deal with today's plethora of non-stationary conditions. In this paper, we introduce spatial imaging-based screening to ecology. We link advancements in spatial resilience theory, data, and technological and computational capabilities and power to detect regime shifts (i.e., vegetation state transitions) that are known to be detrimental to human well-being and ecosystem service delivery. With a state-of-the-art landcover dataset and freely available, cloud-based, geospatial computing platform, we screen for spatial signals of the three most iconic vegetation transitions studied in western USA rangelands: (1) erosion and desertification; (2) woody encroachment; and (3) annual exotic grass invasion. For a series of locations that differ in ecological complexity and geographic extent, we answer the following questions: (1) Which regime shift is expected or of greatest concern? (2) Can we detect a signal associated with the expected regime shift? (3) If detected, is the signal transient or persistent over time? (4) If detected and persistent, is the transition signal stationary or non-stationary over time? (5) What other signals do we detect? Our approach reveals a powerful and flexible methodology, whereby professionals can use spatial imaging to verify the occurrence of alternative vegetation regimes, image the spatial boundaries separating regimes, track the magnitude and direction of regime shift signals, differentiate persistent and stationary transition signals that warrant continued screening from more concerning persistent and non-stationary transition signals, and leverage disciplinary strength and resources for more targeted diagnostic testing (e.g., inventory and monitoring) and treatment (e.g., management) of regime shifts. While the rapid screening approach used here can continue to be implemented and refined for rangelands, it has broader implications and can be adapted to other ecological systems to revolutionize the information space needed to better manage critical transitions in nature.
Remote Sensing in Ecology and Conservation, Jul 19, 2023
Worldwide, trees are colonizing rangelands with high conservation value. The introduction of tree... more Worldwide, trees are colonizing rangelands with high conservation value. The introduction of trees into grasslands and shrublands causes large‐scale changes in ecosystem structure and function, which have cascading impacts on ecosystem services, biodiversity, and agricultural economies. Satellites are increasingly being used to track tree cover at continental to global scales, but these methods can only provide reliable estimates of change over recent decades. Given the slow pace of tree cover expansion, remote sensing techniques that can extend this historical record provide critical insights into the magnitude of environmental change. Here, we estimate conifer expansion in rangelands of the northern Great Plains, United States, North America, using historical aerial imagery from the mid‐20th century and modern aerial imagery. We analyzed 19.3 million hectares of rangelands in Montana, USA, using a convolutional neural network (U‐Net architecture) and cloud computing to detect tree features and tree cover change. Our bias‐corrected results estimate 3.0 ± 0.2 million hectares of conifer tree cover expansion in Montana rangelands, which accounts for 15.4% of the total study area. Overall accuracy was >91%, but the producer's accuracy was lower than the user's accuracy (0.60 vs. 0.88) for areas of tree cover expansion. Nonetheless, the omission errors were not spatially clustered, suggesting that the method is reliable for identifying the regions of Montana where substantial tree expansion has occurred. Using the model results in conjunction with historical and modern imagery allows for effective communication of the scale of tree expansion while overcoming the recency effect caused by shifting environmental baselines.
bioRxiv (Cold Spring Harbor Laboratory), Nov 2, 2021
Rangelands of the United States provide ecosystem services that sustain biodiversity and rural ec... more Rangelands of the United States provide ecosystem services that sustain biodiversity and rural economies. Native tree encroachment is a recognized and long-standing conservation challenge to these landscapes, but its impact is often overlooked due to the slow pace of tree invasions and the positive public perception of trees. Here we show that tree encroachment is a dominant change agent in U.S. rangelands; tree cover has increased by more than 77,000 km2 over 30 years, and more than 25% of U.S. rangelands are now experiencing sustained tree cover expansion. Further, we use machine learning methods to estimate the potential herbaceous production (forage) lost to tree encroachment. Since 1990 roughly 300 Tg of herbaceous biomass has been lost, totaling some $5 billion in foregone revenue to agricultural producers. These results suggest that tree encroachment is similar in scale and magnitude to row-crop conversion, another primary cause of rangeland loss in the U.S. Prioritizing conservation efforts to prevent tree encroachment in rangelands can bolster ecosystem and economic sustainability of these landscapes, particularly among privately-owned lands threatened by land-use conversion. Significance Statement Rangeland biomes are being rapidly lost and degraded due to expansion of row-crop agriculture, the built environment, and a proliferation of exotic plants. Tree expansion in rangelands exacerbates these losses but has been difficult to track at large scales due to the slow, incremental pace of tree spread. Here we use improved satellite technology to map the scale of tree cover expansion and its impact on forage production across U.S. rangelands. We reveal that the pace of tree expansion is similar in magnitude to grassland cultivation (tillage) and establish that forage losses from tree encroachment may threaten the economic sustainability and conservation value of working rangelands that are critical habitat to some of the most imperiled species in North America.
This is an open access article under the terms of the Creative Commons Attribution License, which... more This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
bioRxiv (Cold Spring Harbor Laboratory), Jan 6, 2021
Aim: In the western US, sagebrush (Artemisia spp.) and salt desert shrublands are rapidly transit... more Aim: In the western US, sagebrush (Artemisia spp.) and salt desert shrublands are rapidly transitioning to communities dominated by exotic annual grasses, a novel and often selfreinforcing state that threatens the economic sustainability and conservation value of rangelands. Climate change is predicted to directly and indirectly favor annual grasses, potentially pushing transitions to annual grass dominance into higher elevations and northfacing aspects. We sought to quantify the expansion of annual grass-dominated vegetation communities along topographic gradients over the past several decades. Location: Our analysis focused on rangelands among three ecoregions in the Great Basin of the western US, where several species of exotic annual grasses are widespread among shrub and perennial grass-dominated vegetation communities.
The expansion of coniferous trees into sagebrush ecosystems is a major driver of habitat loss and... more The expansion of coniferous trees into sagebrush ecosystems is a major driver of habitat loss and fragmentation, resulting in negative impacts to wildlife. Greater sage-grouse (Centrocercus urophasianus) respond directly to conifer expansion through decreased breeding activity, nesting, and overall survival; thus, small amounts of conifer expansion can have significant impacts on sage-grouse habitat and populations. To this end, conservation partners have collaborated across private and public lands to reduce the threat of conifer expansion through targeted removal of conifer trees. Here, we demonstrate the use of the Marxan framework to incorporate important ecosystem attributes in the prioritization of conifer removal within the Oregon range of sage-grouse. We prioritized conifer removal relative to three separate goals: (1) enhancement of existing sage-grouse breeding, nesting, and early brood-rearing habitats; (2) facilitation of sage-grouse movement between breeding and brood-rearing habitats; and (3) improvement of connectivity among sage-grouse priority areas for conservation (PACs). Optimization models successfully identified areas with low conifer canopy cover, high resilience and resistance to wildfire and annual grass invasion, and high bird abundance to enhance sage-grouse habitat. The inclusion of mesic resources resulted in further prioritization of areas that were closer to such resources, but also identified potential pathways that connected breeding habitats to the late brood-rearing habitats associated with mesic areas. Examining areas outside of PACs resulted in the selection of potential corridors to facilitate connectivity; although areas with low conifer cover were selected similarly to the other optimization models, areas with high cover were also chosen to be able to enhance connectivity. Areas identified by optimization models were largely consistent with and overlapped ongoing conifer removal efforts in the Warner Mountains of south-central Oregon. Land ownership of preferential areas selected by models varied with priority goals and followed general ownership patterns of the region, with public lands managed by the Bureau of Land Management and private lands being selected the most. The increased availability of landscape-level datasets and assessment tools in sagebrush ecosystems can reduce the time and cost of both planning and implementation of habitat projects involving conifer removal. Most importantly, incorporating these new datasets and tools can supplement expert-based knowledge to maximize benefits to sagebrush and sage-grouse conservation.
BioOne Complete (complete.BioOne.org) is a full-text database of 200 subscribed and open-access t... more BioOne Complete (complete.BioOne.org) is a full-text database of 200 subscribed and open-access titles in the biological, ecological, and environmental sciences published by nonprofit societies, associations, museums, institutions, and presses.
Wind energy offers the potential to reduce carbon emissions while increasing energy independence ... more Wind energy offers the potential to reduce carbon emissions while increasing energy independence and bolstering economic development. However, wind energy has a larger land footprint per Gigawatt (GW) than most other forms of energy production, making appropriate siting and mitigation particularly important. Species that require large unfragmented habitats and those known to avoid vertical structures are particularly at risk from wind development. Developing energy on disturbed lands rather than placing new developments within large and intact habitats would reduce cumulative impacts to wildlife. The U.S. Department of Energy estimates that it will take 241 GW of terrestrial based wind development on approximately 5 million hectares to reach 20% electricity production for the U.S. by 2030. We estimate there are ,7,700 GW of potential wind energy available across the U.S., with ,3,500 GW on disturbed lands. In addition, a disturbance-focused development strategy would avert the development of ,2.3 million hectares of undisturbed lands while generating the same amount of energy as development based solely on maximizing wind potential. Wind subsidies targeted at favoring low-impact developments and creating avoidance and mitigation requirements that raise the costs for projects impacting sensitive lands could improve public value for both wind energy and biodiversity conservation.
bioRxiv (Cold Spring Harbor Laboratory), Nov 8, 2020
Rangeland production is a foundational ecosystem service and resource upon which livestock, wildl... more Rangeland production is a foundational ecosystem service and resource upon which livestock, wildlife, and people depend. Capitalizing on recent advancements in the use of remote sensing data across rangelands we provide estimates of herbaceous rangeland production from 1986-2019 at 16-day and annual time steps and 30m resolution across the western United States. Herbaceous aboveground biomass at this scale and resolution provide critical information applicable for management and decision-making, particularly in the face of annual grass invasion and woody encroachment of rangeland systems. These readily available data remove analytical and technological barriers allowing immediate utilization for monitoring and management.
Restoration of riparian and wet meadow ecosystems in semiarid rangelands of the western United St... more Restoration of riparian and wet meadow ecosystems in semiarid rangelands of the western United States is a high priority given their ecological and hydrological importance in the region. However, traditional restoration approaches are often intensive and costly, limiting the extent over which they can be applied. Practitioners are increasingly trying new restoration techniques that are more cost-effective, less intensive, and can more practically scale up to the scope of degradation. Unfortunately, practitioners typically lack resources to undertake outcome-based evaluations necessary to judge the efficacy of these techniques. In this study, we use freely available, satellite remote sensing to explore changes in vegetation productivity (normalized difference vegetation index) of three distinct, low-tech, riparian and wet meadow restoration projects. Case studies are presented that range in geographic location (Colorado, Oregon, and Nevada), restoration practice (Zeedyk structures, beaver dam analogs, and grazing management), and time since implementation. Restoration practices resulted in increased vegetation productivity of up to 25% and increased annual persistence of productive vegetation. Improvements in productivity with time since restoration suggest that elevated resilience may further enhance wildlife habitat and increase forage production. Long-term, documented outcomes of conservation are rare; we hope our findings empower practitioners to further monitor and explore the use of low-tech methods for restoration of ecohydrologic processes at meaningful spatial scales.
Partnerships across agencies and land ownerships established to maintain wildlife-compatible “wor... more Partnerships across agencies and land ownerships established to maintain wildlife-compatible “working landscapes” are critical for conserving and managing wildlife in the West. Preliminary results from the first three years of a 10-yr study in central Montana demonstrate this management approach. We are evaluating prescribed grazing systems implemented by NRCS’s Sage Grouse Initiative (SGI) that are designed to improve hiding cover and food availability for Greater sage grouse (Centrocercus urophasianus) during critical life stages via voluntary, incentive-based modifications of livestock grazing management. Extensive vegetation sampling across 8 SGI-enrolled ranches and 20 non-enrolled ranches in 2013 revealed significant increases in residual grass height, live grass height, and herbaceous vegetation cover on SGI-enrolled lands. In 2011-2013, we monitored adult female sage-grouse and chicks with radiotelemetry to measure vital rates and habitat use. Annual hen survival ranged f...
Wildfires are ecosystem‐level drivers of structure and function in many vegetated biomes. While n... more Wildfires are ecosystem‐level drivers of structure and function in many vegetated biomes. While numerous studies have emphasized the benefits of fire to ecosystems, large wildfires have also been associated with the loss of ecosystem services and shifts in vegetation abundance. The size and number of wildfires are increasing across a number of regions, and yet the outcomes of large wildfire on vegetation at large‐scales are still largely unknown. We introduce an exhaustive analysis of wildfire‐scale vegetation response to large wildfires across North America's grassland biome. We use 18 years of a newly released vegetation data set combined with 1,390 geospatial wildfire perimeters and drought data to detect large‐scale vegetation response among multiple vegetation functional groups. We found no evidence of persistent declines in vegetation driven by wildfire at the biome level. All vegetation functional groups exhibited relatively rapid recovery to pre wildfire ranges of variat...
Operational satellite remote sensing products are transforming rangeland management and science. ... more Operational satellite remote sensing products are transforming rangeland management and science. Advancements in computation, data storage, and processing have removed barriers that previously blocked or hindered the development and use of remote sensing products. When combined with local data and knowledge, remote sensing products can inform decision making at multiple scales.We used temporal convolutional networks to produce a fractional cover product that spans western United States rangelands. We trained the model with 52,012 on-the-ground vegetation plots to simultaneously predict fractional cover for annual forbs and grasses, perennial forbs and grasses, shrubs, trees, litter, and bare ground. To assist interpretation and to provide a measure of prediction confidence, we also produced spatiotemporal-explicit, pixel-level estimates of uncertainty. We evaluated the model with 5,780 on-the-ground vegetation plots removed from the training data.Model evaluation averaged 6.3% mean ...
In semi‐arid ecosystems, timing and availability of water is a key uncertainty associated with co... more In semi‐arid ecosystems, timing and availability of water is a key uncertainty associated with conservation planning for wetland‐dependent wildlife. Wetlands compose only 1–3% of these landscapes; however, large populations of migratory waterbirds rely on these wetlands to support energetically demanding life history events such as breeding and migration. Migration is considered a crucial period for birds associated with individual survival and reproductive success, yet our understanding of migration ecology remains limited. To better inform conservation planning supportive of these demands, we quantified synchrony of wetland flooding and waterbird migration by reconstructing bi‐monthly surface water patterns from 1984 to 2015 across 11.4 million ha of the semi‐arid Great Basin, USA. Results were then linked to seasonal migration chronologies for seven dabbling ducks species. Seasonal patterns were used in landscape planning simulations to assess efficiency in conservation strategie...
This is an open access article under the terms of the Creative Commons Attribution License, which... more This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
Screening is a strategy for detecting undesirable change prior to manifestation of symptoms or ad... more Screening is a strategy for detecting undesirable change prior to manifestation of symptoms or adverse effects. Although the well-recognized utility of screening makes it commonplace in medicine, it has yet to be implemented in ecosystem management. Ecosystem management is in an era of diagnosis and treatment of undesirable change, and as a result, remains more reactive than proactive and unable to effectively deal with today's plethora of non-stationary conditions. In this paper, we introduce spatial imaging-based screening to ecology. We link advancements in spatial resilience theory, data, and technological and computational capabilities and power to detect regime shifts (i.e., vegetation state transitions) that are known to be detrimental to human well-being and ecosystem service delivery. With a state-of-the-art landcover dataset and freely available, cloud-based, geospatial computing platform, we screen for spatial signals of the three most iconic vegetation transitions studied in western USA rangelands: (1) erosion and desertification; (2) woody encroachment; and (3) annual exotic grass invasion. For a series of locations that differ in ecological complexity and geographic extent, we answer the following questions: (1) Which regime shift is expected or of greatest concern? (2) Can we detect a signal associated with the expected regime shift? (3) If detected, is the signal transient or persistent over time? (4) If detected and persistent, is the transition signal stationary or non-stationary over time? (5) What other signals do we detect? Our approach reveals a powerful and flexible methodology, whereby professionals can use spatial imaging to verify the occurrence of alternative vegetation regimes, image the spatial boundaries separating regimes, track the magnitude and direction of regime shift signals, differentiate persistent and stationary transition signals that warrant continued screening from more concerning persistent and non-stationary transition signals, and leverage disciplinary strength and resources for more targeted diagnostic testing (e.g., inventory and monitoring) and treatment (e.g., management) of regime shifts. While the rapid screening approach used here can continue to be implemented and refined for rangelands, it has broader implications and can be adapted to other ecological systems to revolutionize the information space needed to better manage critical transitions in nature.
Remote Sensing in Ecology and Conservation, Jul 19, 2023
Worldwide, trees are colonizing rangelands with high conservation value. The introduction of tree... more Worldwide, trees are colonizing rangelands with high conservation value. The introduction of trees into grasslands and shrublands causes large‐scale changes in ecosystem structure and function, which have cascading impacts on ecosystem services, biodiversity, and agricultural economies. Satellites are increasingly being used to track tree cover at continental to global scales, but these methods can only provide reliable estimates of change over recent decades. Given the slow pace of tree cover expansion, remote sensing techniques that can extend this historical record provide critical insights into the magnitude of environmental change. Here, we estimate conifer expansion in rangelands of the northern Great Plains, United States, North America, using historical aerial imagery from the mid‐20th century and modern aerial imagery. We analyzed 19.3 million hectares of rangelands in Montana, USA, using a convolutional neural network (U‐Net architecture) and cloud computing to detect tree features and tree cover change. Our bias‐corrected results estimate 3.0 ± 0.2 million hectares of conifer tree cover expansion in Montana rangelands, which accounts for 15.4% of the total study area. Overall accuracy was >91%, but the producer's accuracy was lower than the user's accuracy (0.60 vs. 0.88) for areas of tree cover expansion. Nonetheless, the omission errors were not spatially clustered, suggesting that the method is reliable for identifying the regions of Montana where substantial tree expansion has occurred. Using the model results in conjunction with historical and modern imagery allows for effective communication of the scale of tree expansion while overcoming the recency effect caused by shifting environmental baselines.
bioRxiv (Cold Spring Harbor Laboratory), Nov 2, 2021
Rangelands of the United States provide ecosystem services that sustain biodiversity and rural ec... more Rangelands of the United States provide ecosystem services that sustain biodiversity and rural economies. Native tree encroachment is a recognized and long-standing conservation challenge to these landscapes, but its impact is often overlooked due to the slow pace of tree invasions and the positive public perception of trees. Here we show that tree encroachment is a dominant change agent in U.S. rangelands; tree cover has increased by more than 77,000 km2 over 30 years, and more than 25% of U.S. rangelands are now experiencing sustained tree cover expansion. Further, we use machine learning methods to estimate the potential herbaceous production (forage) lost to tree encroachment. Since 1990 roughly 300 Tg of herbaceous biomass has been lost, totaling some $5 billion in foregone revenue to agricultural producers. These results suggest that tree encroachment is similar in scale and magnitude to row-crop conversion, another primary cause of rangeland loss in the U.S. Prioritizing conservation efforts to prevent tree encroachment in rangelands can bolster ecosystem and economic sustainability of these landscapes, particularly among privately-owned lands threatened by land-use conversion. Significance Statement Rangeland biomes are being rapidly lost and degraded due to expansion of row-crop agriculture, the built environment, and a proliferation of exotic plants. Tree expansion in rangelands exacerbates these losses but has been difficult to track at large scales due to the slow, incremental pace of tree spread. Here we use improved satellite technology to map the scale of tree cover expansion and its impact on forage production across U.S. rangelands. We reveal that the pace of tree expansion is similar in magnitude to grassland cultivation (tillage) and establish that forage losses from tree encroachment may threaten the economic sustainability and conservation value of working rangelands that are critical habitat to some of the most imperiled species in North America.
This is an open access article under the terms of the Creative Commons Attribution License, which... more This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
bioRxiv (Cold Spring Harbor Laboratory), Jan 6, 2021
Aim: In the western US, sagebrush (Artemisia spp.) and salt desert shrublands are rapidly transit... more Aim: In the western US, sagebrush (Artemisia spp.) and salt desert shrublands are rapidly transitioning to communities dominated by exotic annual grasses, a novel and often selfreinforcing state that threatens the economic sustainability and conservation value of rangelands. Climate change is predicted to directly and indirectly favor annual grasses, potentially pushing transitions to annual grass dominance into higher elevations and northfacing aspects. We sought to quantify the expansion of annual grass-dominated vegetation communities along topographic gradients over the past several decades. Location: Our analysis focused on rangelands among three ecoregions in the Great Basin of the western US, where several species of exotic annual grasses are widespread among shrub and perennial grass-dominated vegetation communities.
The expansion of coniferous trees into sagebrush ecosystems is a major driver of habitat loss and... more The expansion of coniferous trees into sagebrush ecosystems is a major driver of habitat loss and fragmentation, resulting in negative impacts to wildlife. Greater sage-grouse (Centrocercus urophasianus) respond directly to conifer expansion through decreased breeding activity, nesting, and overall survival; thus, small amounts of conifer expansion can have significant impacts on sage-grouse habitat and populations. To this end, conservation partners have collaborated across private and public lands to reduce the threat of conifer expansion through targeted removal of conifer trees. Here, we demonstrate the use of the Marxan framework to incorporate important ecosystem attributes in the prioritization of conifer removal within the Oregon range of sage-grouse. We prioritized conifer removal relative to three separate goals: (1) enhancement of existing sage-grouse breeding, nesting, and early brood-rearing habitats; (2) facilitation of sage-grouse movement between breeding and brood-rearing habitats; and (3) improvement of connectivity among sage-grouse priority areas for conservation (PACs). Optimization models successfully identified areas with low conifer canopy cover, high resilience and resistance to wildfire and annual grass invasion, and high bird abundance to enhance sage-grouse habitat. The inclusion of mesic resources resulted in further prioritization of areas that were closer to such resources, but also identified potential pathways that connected breeding habitats to the late brood-rearing habitats associated with mesic areas. Examining areas outside of PACs resulted in the selection of potential corridors to facilitate connectivity; although areas with low conifer cover were selected similarly to the other optimization models, areas with high cover were also chosen to be able to enhance connectivity. Areas identified by optimization models were largely consistent with and overlapped ongoing conifer removal efforts in the Warner Mountains of south-central Oregon. Land ownership of preferential areas selected by models varied with priority goals and followed general ownership patterns of the region, with public lands managed by the Bureau of Land Management and private lands being selected the most. The increased availability of landscape-level datasets and assessment tools in sagebrush ecosystems can reduce the time and cost of both planning and implementation of habitat projects involving conifer removal. Most importantly, incorporating these new datasets and tools can supplement expert-based knowledge to maximize benefits to sagebrush and sage-grouse conservation.
BioOne Complete (complete.BioOne.org) is a full-text database of 200 subscribed and open-access t... more BioOne Complete (complete.BioOne.org) is a full-text database of 200 subscribed and open-access titles in the biological, ecological, and environmental sciences published by nonprofit societies, associations, museums, institutions, and presses.
Wind energy offers the potential to reduce carbon emissions while increasing energy independence ... more Wind energy offers the potential to reduce carbon emissions while increasing energy independence and bolstering economic development. However, wind energy has a larger land footprint per Gigawatt (GW) than most other forms of energy production, making appropriate siting and mitigation particularly important. Species that require large unfragmented habitats and those known to avoid vertical structures are particularly at risk from wind development. Developing energy on disturbed lands rather than placing new developments within large and intact habitats would reduce cumulative impacts to wildlife. The U.S. Department of Energy estimates that it will take 241 GW of terrestrial based wind development on approximately 5 million hectares to reach 20% electricity production for the U.S. by 2030. We estimate there are ,7,700 GW of potential wind energy available across the U.S., with ,3,500 GW on disturbed lands. In addition, a disturbance-focused development strategy would avert the development of ,2.3 million hectares of undisturbed lands while generating the same amount of energy as development based solely on maximizing wind potential. Wind subsidies targeted at favoring low-impact developments and creating avoidance and mitigation requirements that raise the costs for projects impacting sensitive lands could improve public value for both wind energy and biodiversity conservation.
bioRxiv (Cold Spring Harbor Laboratory), Nov 8, 2020
Rangeland production is a foundational ecosystem service and resource upon which livestock, wildl... more Rangeland production is a foundational ecosystem service and resource upon which livestock, wildlife, and people depend. Capitalizing on recent advancements in the use of remote sensing data across rangelands we provide estimates of herbaceous rangeland production from 1986-2019 at 16-day and annual time steps and 30m resolution across the western United States. Herbaceous aboveground biomass at this scale and resolution provide critical information applicable for management and decision-making, particularly in the face of annual grass invasion and woody encroachment of rangeland systems. These readily available data remove analytical and technological barriers allowing immediate utilization for monitoring and management.
Restoration of riparian and wet meadow ecosystems in semiarid rangelands of the western United St... more Restoration of riparian and wet meadow ecosystems in semiarid rangelands of the western United States is a high priority given their ecological and hydrological importance in the region. However, traditional restoration approaches are often intensive and costly, limiting the extent over which they can be applied. Practitioners are increasingly trying new restoration techniques that are more cost-effective, less intensive, and can more practically scale up to the scope of degradation. Unfortunately, practitioners typically lack resources to undertake outcome-based evaluations necessary to judge the efficacy of these techniques. In this study, we use freely available, satellite remote sensing to explore changes in vegetation productivity (normalized difference vegetation index) of three distinct, low-tech, riparian and wet meadow restoration projects. Case studies are presented that range in geographic location (Colorado, Oregon, and Nevada), restoration practice (Zeedyk structures, beaver dam analogs, and grazing management), and time since implementation. Restoration practices resulted in increased vegetation productivity of up to 25% and increased annual persistence of productive vegetation. Improvements in productivity with time since restoration suggest that elevated resilience may further enhance wildlife habitat and increase forage production. Long-term, documented outcomes of conservation are rare; we hope our findings empower practitioners to further monitor and explore the use of low-tech methods for restoration of ecohydrologic processes at meaningful spatial scales.
Partnerships across agencies and land ownerships established to maintain wildlife-compatible “wor... more Partnerships across agencies and land ownerships established to maintain wildlife-compatible “working landscapes” are critical for conserving and managing wildlife in the West. Preliminary results from the first three years of a 10-yr study in central Montana demonstrate this management approach. We are evaluating prescribed grazing systems implemented by NRCS’s Sage Grouse Initiative (SGI) that are designed to improve hiding cover and food availability for Greater sage grouse (Centrocercus urophasianus) during critical life stages via voluntary, incentive-based modifications of livestock grazing management. Extensive vegetation sampling across 8 SGI-enrolled ranches and 20 non-enrolled ranches in 2013 revealed significant increases in residual grass height, live grass height, and herbaceous vegetation cover on SGI-enrolled lands. In 2011-2013, we monitored adult female sage-grouse and chicks with radiotelemetry to measure vital rates and habitat use. Annual hen survival ranged f...
Wildfires are ecosystem‐level drivers of structure and function in many vegetated biomes. While n... more Wildfires are ecosystem‐level drivers of structure and function in many vegetated biomes. While numerous studies have emphasized the benefits of fire to ecosystems, large wildfires have also been associated with the loss of ecosystem services and shifts in vegetation abundance. The size and number of wildfires are increasing across a number of regions, and yet the outcomes of large wildfire on vegetation at large‐scales are still largely unknown. We introduce an exhaustive analysis of wildfire‐scale vegetation response to large wildfires across North America's grassland biome. We use 18 years of a newly released vegetation data set combined with 1,390 geospatial wildfire perimeters and drought data to detect large‐scale vegetation response among multiple vegetation functional groups. We found no evidence of persistent declines in vegetation driven by wildfire at the biome level. All vegetation functional groups exhibited relatively rapid recovery to pre wildfire ranges of variat...
Operational satellite remote sensing products are transforming rangeland management and science. ... more Operational satellite remote sensing products are transforming rangeland management and science. Advancements in computation, data storage, and processing have removed barriers that previously blocked or hindered the development and use of remote sensing products. When combined with local data and knowledge, remote sensing products can inform decision making at multiple scales.We used temporal convolutional networks to produce a fractional cover product that spans western United States rangelands. We trained the model with 52,012 on-the-ground vegetation plots to simultaneously predict fractional cover for annual forbs and grasses, perennial forbs and grasses, shrubs, trees, litter, and bare ground. To assist interpretation and to provide a measure of prediction confidence, we also produced spatiotemporal-explicit, pixel-level estimates of uncertainty. We evaluated the model with 5,780 on-the-ground vegetation plots removed from the training data.Model evaluation averaged 6.3% mean ...
In semi‐arid ecosystems, timing and availability of water is a key uncertainty associated with co... more In semi‐arid ecosystems, timing and availability of water is a key uncertainty associated with conservation planning for wetland‐dependent wildlife. Wetlands compose only 1–3% of these landscapes; however, large populations of migratory waterbirds rely on these wetlands to support energetically demanding life history events such as breeding and migration. Migration is considered a crucial period for birds associated with individual survival and reproductive success, yet our understanding of migration ecology remains limited. To better inform conservation planning supportive of these demands, we quantified synchrony of wetland flooding and waterbird migration by reconstructing bi‐monthly surface water patterns from 1984 to 2015 across 11.4 million ha of the semi‐arid Great Basin, USA. Results were then linked to seasonal migration chronologies for seven dabbling ducks species. Seasonal patterns were used in landscape planning simulations to assess efficiency in conservation strategie...
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