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At least 559 records · Page 31Linked to original sources

The state of the giant sequoias: Losses, risks, and opportunities

Background Giant sequoias, an iconic tree found only in a narrow band along the western slope of the Sierra Nevada of California, are facing unprecedented threats. Despite being adapted to fire and resistant to both drought and insect attack, the species has exhibited signs of vulnerability to these stressors in recent years, with the most substantial impacts coming from wildfire. Recently, several unprecedentedly large and severe fires have resulted in the deaths of many large trees and, in some cases, limited postfire regeneration. These impacts have led to heightened efforts by managers to implement treatments to protect those places that are still vulnerable. Here, we provide a comprehensive, range-wide assessment of the condition of the species, including an evaluation of the trends in wildfire and its effects on large giant sequoia mortality and the potential for local extirpation, treatment patterns, and vulnerability to future fire. Results From 2015 to 2024, 82% of giant sequoia grove area burned in wildfire, compared to 24% between 1910 and 2014. We conservatively estimate that 17.6% of all large giant sequoias have been killed by wildfire since 1984, with most dying in 2020 and 2021. Due to very severe wildfire, roughly 13% of the range is at some risk of local extirpation due to the loss of mature trees and limited predicted regeneration. Treatment activity has increased since 1995, with treatment type and amount varying by jurisdiction. The combination of treatment and wildfire has created a mosaic of resistance to severe fire, with 26% of grove area at high resistance, 38% at moderate resistance, 2% at low resistance, and 16% having no resistance. The remaining 18% are areas where mature giant sequoia forest was lost due to high severity fire. Conclusions Giant sequoias have experienced substantial losses due to recent wildfire, with large areas at risk of grove loss. However, most burned area had lower severity effects, creating opportunities to leverage wildfire as a treatment. When combined with areas of active management, these opportunities can promote giant sequoia conservation in a time of rapid change.

California↗

Delta-Flux: An eddy covariance network for a climate-smart Lower Mississippi Basin

Networks of remotely monitored research sites are increasingly the tool used to study regional agricultural impacts on carbon and water fluxes. However, key national networks such as the National Ecological Observatory Network and AmeriFlux lack contributions from the Lower Mississippi River Basin (LMRB), a highly productive agricultural area with opportunities for soil carbon sequestration through conservation practices. The authors describe the rationale to create the new Delta-Flux network, which will coordinate efforts to quantify carbon and water budgets at seventeen eddy covariance flux tower sites in the LMRB. The network structure will facilitate climate-smart management strategies based on production-scale and continuous measurements of carbon and water fluxes from the landscape to the atmosphere under different soil and water management conditions. The seventeen instrumented field sites are expected to monitor fluxes within the most characteristic landscapes of the target area: row-crop fields, pasture, grasslands, forests, and marshes. The network participants are committed to open collaboration and efficient regionalization of site-level findings to support sustainable agricultural and forestry management and conservation of natural resources.

Arkansas, Louisiana, Mississippi↗

Broad-scale geographic and temporal assessment of northern long-eared bat (Myotis septentrionalis) maternity colony-landscape association

As the federally threatened northern long-eared bat Myotis septentrionalis continues to decline due to white-nose syndrome (WNS) impacts, the application of effective conservation measures is needed but often hindered by the lack of ecological data. To date, recommended management practices have been adopted in part from other federally listed sympatric species such as the endangered Indiana bat M. sodalis . During the maternity season, these measures have largely focused on conservation of known day-roost habitat, often with little consideration for foraging habitat, particularly riparian areas. We examined acoustic activity of northern long-eared bats relative to day-roost and capture data at coastal and interior sites in the District of Columbia, New York, Pennsylvania, Virginia, and West Virginia, USA, over the course of 6 summers (2015-2020), where maternity activity was still documented after the initial arrival and spread of WNS. Acoustic activity of northern long-eared bats relative to forest cover decreased at the acoustic site level (fine scale) but increased at the sampling region level (coarse scale). We observed a positive association of northern long-eared bat acoustic activity with riparian areas. Additionally, we observed higher levels of activity during pregnancy through early lactation period of the reproductive cycle prior to juvenile volancy. Our findings suggest the need for more explicit inclusion of forested riparian habitats in northern long-eared bat conservation planning. Acoustic sampling in spring and early summer rather than mid- to late summer and in forested riparian areas is the most effective strategy for identifying potential active northern long-eared bat maternity colonies on the local landscape.

Maryland, New York, Pennsylvania, Virginia, and We↗

Vascular Plant and Vertebrate Inventory of Chiricahua National Monument

This report summarizes the results of the first comprehensive inventory of vascular plants and vertebrates at Chiricahua National Monument (NM) in Arizona. This project was part of a larger effort to inventory vascular plants and vertebrates in eight National Park Service units in the Sonoran Desert Network of parks in Arizona and New Mexico. In 2002, 2003, and 2004 we surveyed for plants and vertebrates (amphibians, reptiles, birds, and mammals) at Chiricahua NM to document the presence of species within the boundaries of the monument. Because we used repeatable study designs and standardized field methods, these inventories can serve as the first step in a biological monitoring program for the monument. This report is also the first summary of previous research from the monument and therefore it provides an important overview of survey efforts to date. We used data from our inventory and previous research to compile complete species lists for the monument and to assess inventory completeness. We recorded a total of 424 species, including 37 not previously found at the monument (Table 1). We found 10 species of non-native plants and one non-native mammal. Most non-native plants were found along the western boundary of the monument. Based on a review of our inventory and past research at the monument, there have been a total of 1,137 species of plants and vertebrates found at the monument. We believe the inventories of vascular plants and vertebrates are nearly complete and that the monument has one of the most complete inventories of any unit in the Sonoran Desert Network. The mammal community at the monument had the highest species richness (69 species) and the amphibian and reptile community was among the lowest species richness (33 species) of any park in the Sonoran Desert Network. Species richness of the plant and bird communities was intermediate. Among the important determinants of species richness for all groups is the geographic location of the monument at the intergrades between the Chihuahuan and Sonoran deserts with influences from the Great Plains and Madrean ecological provinces. The diversity of plants results from a wide variety of soil types and aspects (from cool, moist canyons to semi-desert grasslands to pine forests). In turn, the vertebrate communities respond to this diversity of vegetation, topography, and microsites. For example, for each taxonomic group we found that some species were only associated with a single community type, most often the riparian areas or semi-desert grasslands. The area of highest species richness for most groups was the western-most portion of Bonita Canyon. The low species richness observed in the amphibian and reptile community was likely because the monument is at the elevational edge of the more species-rich semi-desert grasslands. This report includes management implications from our work and suggestions for how the monument staff might better maintain or enhance the unique biological resources of the monument. We suggest additional inventory, monitoring, and research studies and we identify components of our effort that could be improved upon, either through the application of new techniques (e.g., establishment of vegetation monitoring plots) or by extending the temporal and/or spatial scope of our work.

Open-File Report↗

Variables associated with nest survival of Golden-winged Warblers ( Vermivora chrysoptera ) among vegetation communities commonly used for nesting

A mong shrubland- and young forest-nesting bird species in North America, Golden-winged Warblers ( Vermivora chrysoptera ) are one of the most rapidly declining partly because of limited nesting habitat. Creation and management of high quality vegetation communities used for nesting are needed to reduce declines. Thus, we examined whether common characteristics could be managed across much of the Golden-winged Warbler’s breeding range to increase daily survival rate (DSR) of nests. We monitored 388 nests on 62 sites throughout Minnesota, Wisconsin, New York, North Carolina, Pennsylvania, Tennessee, and West Virginia. We evaluated competing DSR models in spatial-temporal (dominant vegetation type, population segment, state, and year), intraseasonal (nest stage and time-within-season), and vegetation model suites. The best-supported DSR models among the three model suites suggested potential associations between daily survival rate of nests and state, time-within-season, percent grass and Rubus cover within 1 m of the nest, and distance to later successional forest edge. Overall, grass cover (negative association with DSR above 50%) and Rubus cover (DSR lowest at about 30%) within 1 m of the nest and distance to later successional forest edge (negative association with DSR) may represent common management targets across our states for increasing Golden-winged Warbler DSR, particularly in the Appalachian Mountains population segment. Context-specific adjustments to management strategies, such as in wetlands or areas of overlap with Blue-winged Warblers ( Vermivora cyanoptera ), may be necessary to increase DSR for Golden-winged Warblers.

Avian Conservation and Ecology↗

Site-scale disturbance and habitat development best predict an index of amphibian biotic integrity in Ohio shrub and forested wetlands

We determined the best predictors of an index of amphibian biotic integrity calculated from 54 shrub and forested wetlands in Ohio, USA using a two-step sequential holdout validation procedure. We considered 13 variables as predictors: four metrics of wetland condition from the Ohio Rapid Assessment Method (ORAM), a wetland vegetation index of biotic integrity, and eight metrics from a landscape disturbance index. For all iterations, the best model included the single ORAM metric that assesses habitat alteration, substrate disturbance, and habitat development within a wetland. Our results align with results of similar studies that have associated high scores for wetland vegetation indices of biotic integrity with low habitat alteration and substrate disturbance within wetlands. Thus, implementing similar management practices (e.g., not removing downed woody debris, retaining natural morphological features, decreasing nutrient input from surrounding agricultural lands) could concurrently increase ecological integrity of both plant and amphibian communities in a wetland. Further, our results have the unexpected effect of making progress toward a more unifying theory of ecological indices.

Ohio↗

Changing landscapes and the cosmopolitism of the eastern Colorado avifauna

The avifauna of continental North America has changed dramatically since colonial times. Excessive hunting contributed, at least in part, to the extinction of birds such as the great auk ( Pinguinus impennis ) and passenger pigeon ( Ectopistes migratorius ), while more recently organochlorine insecticide residues have resulted in drastic reductions in numbers of brown pelicans ( Pelecanus occidentalis ) (Anderson et al. 1975) and other species. Generally, however, vertebrate populations change in direct response to changes in their habitats. For example, herring gulls ( Larus argentatus ) have increased in numners (Kadlec and Drury 1968) with urbanization of the New England coastline, in the same locations formerly occupied by the extinct heath hen ( Tympanuchus cupido cupido ). Also, passerine birds of forest interiors have declined in numbers with fragmentation of the eastern deciduous forest into small stands; this fragmentation has led to increases in numbers of edge species (Robbins 1979, Ambuel and Temple 1983). Even subtle community shifts can introduce new competitive processes that can augment population changes among species (Brittingham and Temple 1983). Such studies of broad-scale changes in vegetative communities and their influence on native wildlife species have fostered the recent topical emphasis on "conservation biology" (Soule and Wilcox 1980, Soule 1985) and "landscape ecology" (Burgess and Sharpe 1981, Harris 1984:25-43). As changes in landscapes are causing subtle (but potentially dramatic) changes in the distribution of native species, conservation biologists are finding that mere presence-absence data on populations, or even accurate information on reproductive success, is inadequate to evaluate management activities or environmental perturbations. The principles of "conservation genetics" are attracting interest in the management of natural preserves especially (Schonewald-Cox et al. 1983). Changing patterns in landscape complexion or genetic makeup of a population are difficult to detect locally. Contemporary issues in the conservation of native species demand regional and continental perspectives (Samson and Knopf 1982). Thus, management activities at specific sites are often viewed as short-sighted by planners and conservation critics. This paper illustrates how these contemporary theories can influence a local conservation perspective. That perspective is developed around historical processes that have led to cosmopolitism of the local avifauna on the Colorado Division of Wildlife's South Platte Wildlife Management Area (SPWMA) near Crook, Colorado.

Colorado↗

Using conservation value to assess land restoration and management alternatives across a degraded oak savanna landscape

1. Managers considering restoration of landscapes often face a fundamental challenge - what should be the habitat composition of the restored landscape? We present a method for evaluating an important conservation trade-off inherent in making that decision. 2. Oak savannas and grasslands were historically widespread across central North America but are now rare. Today, in north-west Indiana, USA, habitats spanning a range of woody vegetation density, from nearly treeless open habitats to forests, occur across the conserved landscape where savannas probably once dominated. To understand the benefits of different potential landscape compositions, we evaluated how different proportions of five habitats - open, savanna, woodland, scrub and forest - might affect the conservation value of the north-west Indiana landscape for birds. Two variables of potential conservation importance were examined: species diversity, a measure of avian community richness, and conservation index, the percentage of a bird species' global population occurring on a hectare of landscape, summed across all bird species present. Higher values of conservation index were associated with higher local densities of globally more rare and more threatened species. 3. Conservation index and species diversity were correlated negatively across hypothetical landscapes composed of different proportions of the five habitats. Therefore, a management trade-off existed between conservation index and species diversity because landscapes that maximized species diversity differed from landscapes that maximized conservation index. 4. A landscape of 50% open, 22% savanna, 15% scrub and 13% forest was predicted to represent a compromise at which conservation index and species diversity reached the same percentage of their maxima. In contrast, the current landscape is dominated by forest. 5. Synthesis and applications. We quantified the trade-off between two potential aspects of a landscape's conservation value for birds - the landscape's ability to promote avian species diversity and the landscape's use by threatened avian species. This quantification allowed us to evaluate the ability of different landscape compositions to achieve preferable trade-off compromises, such as maximizing diversity for a given level of landscape use by threatened species. Managers can use these trade-off results to determine which landscape compositions are associated with particular conservation and management priorities.

Journal of Applied Ecology↗

Mountain sentinels in a changing world: Review and conservation implications of weather and climate effects on mountain goats (Oreamnos americanus)

Climate change is occurring at an accelerated rate in high-elevation alpine and mountain ecosystems. Cold-adapted, mountain species are at risk due to forecasted change and knowledge is needed to respond to current and future conservation challenges. Mountain goats ( Oreamnos americanus ) are an iconic species of North American mountain cultures and landscapes, and due to specialized adaptations for life in cold, mountainous environments they are particularly sensitive to changes in weather and climate. As sentinels of change in alpine ecosystems, the study of mountain goats offers insight into the ecological effects and conservation challenges associated with climate change in these sensitive and biodiverse environments. Here, we synthesize existing knowledge about how climate change is expected to influence environmental conditions experienced by mountain goats and associated mechanistic changes to behavior, nutritional ecology, demography, health, and interspecific interactions. In many instances, climate change effects are likely to be negative and additive to existing threats (such as human disturbance, hunting, disease, predation) though benefits are expected in some cases. Changes in climate and mountain environments will necessitate re-examination and modification of population monitoring, management, and conservation strategies. Specifically, spatiotemporal (and other) aspects of monitoring and management may need to be adjusted to accommodate emerging and novel conservation challenges. Yet, key data and knowledge gaps remain and should be addressed to advance conservation and decision-making capabilities. For mountain goats and similarly climate-sensitive alpine herbivores, effective conservation will ultimately benefit from collaborations among diverse networks guided by well-planned, strategic visions focused on common ground – namely the resiliency and persistence of culturally and ecologically significant mountain species and the alpine environment they inhabit.

Alaska, Alberta, British Columbia, Idaho, Montana,↗

Scenario planning and multispecies occupancy models reveal positive avian responses to restoration of afforested woodlands

Scenario planning is a powerful approach for assessing restoration outcomes under alternative futures. However, developing plausible scenarios remains daunting in complex systems like ecological communities. Here, we used Bayesian multispecies occupancy modeling to develop scenarios to assess woodland restoration outcomes in afforested communities in seven wildlife management areas in Arkansas, U.S.A. Our objectives were (1) to define plausible woodland restoration and afforestation scenarios by quantifying historic ranges of variation in mean tree cover and tree cover heterogeneity from 1986 to 2021 and (2) to predict changes in bird species richness and occupancy patterns for six species of greatest conservation need under two future scenarios: complete afforestation (100% tree cover) and woodland restoration (based on remotely sensed historic tree cover). Using 35 years of remotely sensed tree cover data and 6 years of bird monitoring data, we developed multispecies occupancy models to predict future bird species richness and occupancy under the complete afforestation and woodland restoration scenarios. Between 1986 and 2021, tree cover increased in all study areas—with one increasing 70%. Under the woodland restoration scenario, avian species richness increased up to 20%, and four of six species of greatest conservation need exhibited gains in occupancy probability. The complete afforestation scenario had negligible effects on richness and occupancy. Overall, we found decreasing tree cover to historic levels prior to widespread afforestation would provide community-level benefits and would do little harm even to forest-dependent species of conservation concern. Applying multispecies occupancy modeling within a scenario planning framework allows for comparing multiscale trade-offs between plausible futures.

Restoration Ecology↗

Basal area loss from fire using field-calibrated remote sensing refines western US fire severity measurements

The spatial patterns of fire effects and tree mortality have profound consequences for forest resilience. Cost-effective, medium-resolution, and spatiotemporally extensive fire severity measurements are essential for informing post-fire restoration and improving our understanding of wildfires—from forest stands to continents and from days to decades. Remote sensing advancements have improved burn severity mapping, but methods vary in interpretability, scalability, generalizability, and alignment with field measurements. One meaningful metric of fire effects on forests is proportion basal area loss, but existing methods are limited by a lack of region-specific field reference data and a scalable mapping framework. To address these issues, we compiled 3280 field reference plots from 123 fires in forests across the Western US to calculate the proportion of fire-induced basal area loss. We then used spatially cross-validated machine learning models with concurrent hyperparameter tuning to select a skillful, parsimonious model from a large candidate set of remotely-sensed, climatic, and topographic predictors. Spectral-only measures of severity over- or underestimated basal area loss in dry versus wet years and across aspects, demonstrating the value of incorporating climatic and topographic context. We also tested model performance on a separate holdout dataset in the Southwest US as a demonstration of reproducibility and transparency. We provide a Google Earth Engine tool for estimating proportional basal area loss for any fire perimeter in the Western US, enabling rapid map creation for land management and ecological modeling. All code, model parameters, and training data are released to support reproducibility, community adoption, regional refinement, and adaptation to new regions.

western United States↗

The effects of management practices on grassland birds

Since the mid-1960s, populations of grassland birds have been declining more precipitously than any other group of birds in North America. These long-term declines highlight the need to better understand the habitat requirements of grassland birds and how management practices affect individual species and their habitats. Although resource managers have long recognized that every management approach contains inherent advantages and disadvantages, depending on the species in question, they are often faced with making critical management decisions armed with little or no information. The need for information on management and its effects on grassland birds was identified by the U.S. Prairie Pothole Joint Venture, a part of the North American Waterfowl Management Plan, in support of its objective to stabilize or increase populations of declining grassland- and wetland-associated wildlife species in the Prairie Pothole Region. In 1996, scientists from the U.S. Geological Survey’s Northern Prairie Wildlife Research Center began a long-term, collaborative effort to review and synthesize literature on the effects of management practices on grassland bird species. Major funding for this effort was provided by the Prairie Pothole Joint Venture, U.S. Fish and Wildlife Service, and the U.S. Geological Survey; additional funding was provided by the U.S. Forest Service, The Nature Conservancy, and the Plains and Potholes Landscape Conservation Cooperative. This compendium on “The Effects of Management Practices on Grassland Birds” is a culmination of that work. More than 6,000 published and unpublished publications have been consulted and several thousand publications have been incorporated and synthesized in species accounts for 40 North American grassland bird species. The 40 species represent a taxonomically diverse group that includes grouse, shorebirds, owls, diurnal raptors, and many songbirds. The focus of this effort is on management of breeding habitat, with an emphasis on the Great Plains. The accounts provide land managers with a summary of information on the effects of specific management practices on grassland birds and help to identify the most critical research gaps in our understanding of grassland bird ecology, habitat needs, and responses to management practices. This compendium is organized into three primary sections: an introduction, species accounts, and a concluding chapter. The introduction provides an overview of grasslands, the processes under which grasslands formed, the influence of anthropogenic changes to grasslands, the effects of those changes on grassland bird populations, and the management tools available to land managers. The bulk of this compendium is the individual species accounts, covering 40 species of North American grassland birds arranged in taxonomic order. Each species account includes information on species range, suitable breeding habitat, area requirements and landscape associations, breeding-season phenology, species’ response to management, and management recommendations. Information on rates of brood parasitism by the Brown-headed Cowbird ( Molothrus ater ) in grassland bird nests is summarized in a chapter at the end of this report. The final chapter includes concluding remarks concerning habitat requirements and management effects on grassland birds.

Professional Paper↗

Developing spatially explicit footprints of plausible land-use scenarios in the Santa Cruz Watershed, Arizona and Sonora

The SLEUTH urban growth model is applied to a binational dryland watershed to envision and evaluate plausible future scenarios of land use change into the year 2050. Our objective was to create a suite of geospatial footprints portraying potential land use change that can be used to aid binational decision-makers in assessing the impacts relative to sustainability of natural resources and potential socio-ecological consequences of proposed land-use management. Three alternatives are designed to simulate different conditions: (i) a Current Trends Scenario of unmanaged exponential growth, (ii) a Conservation Scenario with managed growth to protect the environment, and (iii) a Megalopolis Scenario in which growth is accentuated around a defined international trade corridor. The model was calibrated with historical data extracted from a time series of satellite images. Model materials, methodology, and results are presented. Our Current Trends Scenario predicts the footprint of urban growth to approximately triple from 2009 to 2050, which is corroborated by local population estimates. The Conservation Scenario results in protecting 46% more of the Evergreen class (more than 150,000 acres) than the Current Trends Scenario and approximately 95,000 acres of Barren Land, Crops, Deciduous Forest (Mesquite Bosque), Grassland/Herbaceous, Urban/Recreational Grasses, and Wetlands classes combined. The Megalopolis Scenario results also depict the preservation of some of these land-use classes compared to the Current Trends Scenario, most notably in the environmentally important headwaters region. Connectivity and areal extent of land cover types that provide wildlife habitat were preserved under the alternative scenarios when compared to Current Trends.

Arizona;Sonora↗

Ecological Investigations of the Federally Endangered Shivwits Milk-Vetch (Astragalus ampullarioides)--2006 Annual Report

Astragalus ampullarioides (Welsh) Welsh, the Shivwits milk-vetch, is an herbaceous perennial legume that was listed as federally endangered in September 2001. Known populations of this edaphic endemic species are restricted to Washington County, Utah, with the majority of occurrences found on gently sloping outcrops of the Triassic Petrified Forest Member of the Chinle Formation at the edge of the Mojave Desert. At the time of listing in 2001, surveys estimated a total of 1000 individuals for the species. In April-May 2006, surveys estimated approximately 4205 individuals distributed among six populations. Of the total number of individuals estimated in spring 2006, over 75 percent were distributed among three subpopulations in Zion National Park and approximately 60 percent occurred at a single 0.3-ha site in the Park. In addition to small population sizes and limited geographic distributions, the species is threatened to varying degrees by urbanization, livestock grazing, off-road vehicle use, and invasive exotic plants. In April 2006, the U.S. Geological Survey (USGS) initiated ecological investigations of the Shivwits milk-vetch to support conservation management and recovery of the species by the National Park Service (NPS; Zion National Park), the U.S. Fish and Wildlife Service (USFWS), the Bureau of Land Management (BLM), the Shivwits Band of the Paiute Tribe, and other cooperators such as The Nature Conservancy of Utah (TNC). To date, funding for this research has been provided by the Southwest Biological Science Center of the USGS Biological Resources Discipline, the USGS-NPS Park-Oriented Biological Support Project, and the Earth Surface Dynamics Program of the USGS Geologic Discipline. Additional logistical support has been provided by the Bureau of Land Management, Grand Staircase-Escalante National Monument. General objectives of this research are (1) to develop a better understanding of species-environment relations to support habitat modelling, future surveys for additional recovery populations, and potential efforts to establish new recovery populations; and (2) to evaluate effects of invasive exotic plants on habitat conditions and measures of milk-vetch performance. Specific objectives are to: Describe the distribution and abundance of milk-vetch populations and associated invasive exotic plant species within and outside of Zion National Park (Zion NP) in relation to geologic / geomorphic setting, soil properties, and plant community composition. In a field setting in Zion NP, conduct experiments to evaluate effects of invasive exotic plants on reproductive output and seedling establishment of A. ampullarioides across a gradient of exotic species biomass. Conduct greenhouse studies and analyze soils to evaluate effects of invasive exotic plants on soil biological properties (including mycorrhizal inocculation potential) that affect cycling and plant uptake of essential mineral nutrients. Based on environmental characteristics of known population locations, use Geographic Information System (GIS) tools to prepare a predictive habitat model that can be used to guide future surveys and efforts to evaluate sites for reintroduction efforts. This report describes 2006 progress and future plans for achieving these four objectives.

Open-File Report↗

Northwest

Key Messages 1. Changes in the timing of streamflow related to changing snowmelt are already observed and will continue, reducing the supply of water for many competing demands and causing far-reaching ecological and socioeconomic consequences. 2. In the coastal zone, the effects of sea level rise, erosion, inundation, threats to infrastructure and habitat, and increasing ocean acidity collectively pose a major threat to the region. 3. The combined impacts of increasing wildfire, insect outbreaks, and tree diseases are already causing widespread tree die-off and are virtually certain to cause additional forest mortality by the 2040s and long-term transformation of forest landscapes. Under higher emissions scenarios, extensive conversion of subalpine forests to other forest types is projected by the 2080s. 4. While the agriculture sector’s technical ability to adapt to changing conditions can offset some adverse impacts of a changing climate, there remain critical concerns for agriculture with respect to costs of adaptation, development of more climate resilient technologies and management, and availability and timing of water.

Idaho, Oregon, Washington↗

A decision support system for prioritizing forested wetland restoration in the Yazoo Backwater Area, Mississippi

A working prototype decision support system (DSS) was developed for the Yazoo Backwater Area, Mississippi, to help planners and managers prioritize, plan, conduct, and optimize forested wetland restoration activities. The DSS comprises geographic information system (GIS) spatial data themes, application programs that provide a cumulative analysis of the relative ability of sites to function as wetlands, and output data that are specific to a given restoration analysis scenario. The DSS input includes GIS data themes such as geomorphology, soils, land use, elevation, farmed wetlands, flood frequency, topographic depressions, streams, public lands, roads, and permanent water bodies, which can be used as spatial templates to define areal hydrologic settings. These GIS data themes can then be ranked and combined to estimate the relative suitability of a potential wetland restoration site, thereby, determining relative wetland equivalence on the landscape. The GIS applications used in this DSS perform the following three functions: assess the ecology (the Eco-Assessor); reclassify land-use in areas selected for restoration (the Tree-Translator); and generate output data to compare restoration scenarios (the Parameter-Generator). Areas selected for reforestation are translated (in the GIS) into ?forested? land use, and the tree species that are ?planted? on the landscape (in the DSS) either compose an ecologically optimal or an economically optimal community of tree species. Output from the DSS can be compared and analyzed by using economic, statistical, graphical, and tabular methods. Output data for seven selected scenarios were generated for the Yazoo Backwater Area and are presented as examples to illustrate the flexibility of the DSS to identify areas that meet restoration objectives.

Water-Resources Investigations Report↗

Individual heterogeneity influences the effects of translocation on urban dispersal of an invasive reptile

Background Invasive reptiles pose a serious threat to global biodiversity, but early detection of individuals in an incipient population is often hindered by their cryptic nature, sporadic movements, and variation among individuals. Little is known about the mechanisms that affect the movement of these species, which limits our understanding of their dispersal. Our aim was to determine whether translocation or small-scale landscape features affect movement patterns of brown treesnakes ( Boiga irregularis ), a destructive invasive predator on the island of Guam. Methods We conducted a field experiment to compare the movements of resident (control) snakes to those of snakes translocated from forests and urban areas into new urban habitats. We developed a Bayesian hierarchical model to analyze snake movement mechanisms and account for attributes unique to invasive reptiles by incorporating multiple behavioral states and individual heterogeneity in movement parameters. Results We did not observe strong differences in mechanistic movement parameters (turning angle or step length) among experimental treatment groups. We found some evidence that translocated snakes from both forests and urban areas made longer movements than resident snakes, but variation among individuals within treatment groups weakened this effect. Snakes translocated from forests moved more frequently from pavement than those translocated from urban areas. Snakes translocated from urban areas moved less frequently from buildings than resident snakes. Resident snakes had high individual heterogeneity in movement probability. Conclusions Our approach to modeling movement improved our understanding of invasive reptile dispersal by allowing us to examine the mechanisms that influence their movement. We also demonstrated the importance of accounting for individual heterogeneity in population-level analyses, especially when management goals involve eradication of an invasive species.

Movement Ecology↗

Breeding productivity of Smith Island black ducks

We investigated the breeding performance of American black ducks (Anas rubripes) on Smith Island, Chesapeake Bay, to improve our understanding of island black duck breeding ecology and to make management recommendations to enhance productivity. During 1995-96, we implanted 56 female black ducks with 20-g radio transmitters and tracked 35 of the individuals through the breeding season to locate nests, determine nest fate, and identify brood habitat. We also increased preseason banding efforts and compared capture characteristics over 12 years with those from the Deal Island Wildlife Management Area, a banding site on the mainland of Tangier Sound. A low rate of nesting (37%), lack of renesting, and poor hatching success (31%) indicated that island salt marsh habitats present a harsh environment for breeding black ducks. Black ducks located 11 of 13 nests (85%) in black needlerush (Juncus roemerianus) marsh where they were vulnerable to flooding from extreme tides and to egg predators. No nests were found on forested tree hammocks, a feature that distinguishes Smith Island from nearby South Marsh and Bloodsworth Islands. Nest predators included red foxes (Vulpes vulpes), herring gulls (Larus argentams), fish crows (Corvus ossifragus), and, potentially, Norway rats (Rattus norvegicus). Unlike mainland red foxes, foxes radio tracked on Smith Island were found to be capable swimmers and effective low marsh predators. We found shoreline meadows of widgeon grass (Ruppia maritima) to be important foraging sites for black ducks and suspected that the virtual absence of fresh water in this high salinity environment (1217+ ppt) to incur some cost in terms of growth and survival of ducklings. Preseason bandings revealed a high proportion of banded adults and a strong positive correlation in age ratios with the Deal Island banding site. This latter finding strongly suggests a negative universal effect of storm tides on nest success for Tangier Sound black ducks. Management to reduce nest predators, especially gulls and foxes, likely will have the greatest immediate benefit for island breeding black ducks.

Book chapter↗