Skip to main content
Advanced Search

Filters: Tags: Western North America (X)

22 results (51ms)   

Filters
Date Range
Extensions
Types
Contacts
Categories
Tag Types
Tag Schemes
View Results as: JSON ATOM CSV
thumbnail
These data were compiled using a new multivariate matching algorithm that transfers simulated soil moisture conditions (Bradford et al. 2020) from an original 10-km resolution to a 30-arcsec spatial resolution. Also, these data are a supplement to a previously published journal article (Bradford et al., 2020) and USGS data release (Bradford and Schlaepfer, 2020). The objectives of our study were to (1) characterize geographic patterns in ecological drought under historical climate, (2) quantify the direction and magnitude of projected responses in ecological drought under climate change, (3) identify areas and drought metrics with projected changes that are robust across climate models for a representative set of...
thumbnail
Characterizing genetic structure across a species’ range is relevant for management and conservation as it can be used to define population boundaries and quantify connectivity. Here, we characterized population structure and estimated effective migration in Greater Sage-grouse (Centrocercus urophasianus). Our objectives were to (1) describe large-scale patterns of population genetic structure and gene flow and (2) to characterize genetic subpopulation centers across the range of Greater Sage-grouse. Samples from 2,134 individuals were genotyped at 15 microsatellite loci. Using standard STRUCTURE and spatial principal components analyses, we found evidence for four or six areas of large-scale genetic differentiation...
Modern pollen assemblages from 18 small ponds and wetlands on the spatially isolated and forested Kaibab Plateau were studied to determine how the pollen assemblages recorded vegetation patterns. Vegetation of the Plateau consists of an inner core of subalpine Picea/Abies forests, surrounded by mixed Abies/Picea/Pseudotsuga/Pinus ponderosa forests, which are in turn surrounded by extensive Pinus ponderosa forests. The flanks of the Plateau are vegetated by Pinus edulis/Juniperus woodlands, with scattered Quercus populations. Arboreal pollen assemblages were dominated by Pinus (70-98%), which was most abundant in the P. ponderosa forests. Picea, Abies, Pseudotsuga and Populus pollen were abundant only at sites in...
These data were compiled as a supplement to a previously published journal article (Bradford et al., 2019), that employed a ecosystem water balance model to characterize current and future patterns in soil temperature and moisture conditions in dryland areas of western North America. Also, these data are associated with a published USGS data release (Bradford and Schlaepfer, 2019). The objectives of our study were to (1) characterize current and future patterns in soil temperature and moisture conditions in dryland areas of western North America, (2) evaluate the impact of these changes on estimation of resilience and resistance among a representative set of climate scenarios. These data represent geographic patterns...
thumbnail
Please contact fresc_outreach@usgs.gov if you have difficulty downloading the data files. We will explore alternative arrangements to deliver the data.
thumbnail
Genetic networks can characterize complex genetic relationships among groups of individuals, which can be used to rank nodes most important to the overall connectivity of the system. Ranking allows scarce resources to be guided towards nodes integral to connectivity. The greater sage-grouse (Centrocercus urophasianus) is a species of conservation concern that breeds on spatially discrete leks that must remain connected by genetic exchange for population persistence. We genotyped 5,950 individuals, from 1,200 greater sage-grouse leks distributed across the entire species’ geographic range. We found a small world network composed of 458 nodes connected by 14,481 edges that are described here. The files associated...
This map depicts the distribution of sagebrush and associated shrub-steppe habitat types using readily available data from a variety of source maps from WA, OR, CA, UT, NV, CO, WY, MT, ND, SD, AZ, NM, AB, and BC. Habitat was grouped from map sources that were classified with detailed information on specific sagebrush types, as well as coarse-scale maps that classified vegetation as only "shrub" in the case of ND and the Canadian provinces. This map is a 90-meter grid, but source material included 30 to 90-meter grids, and 1:24,000 and 1:100,000 polygon coverages.
Aim The influence of anthropogenic climate change on organisms is an area of great scientific concern. Increasingly there is recognition that abrupt climate transitions have occurred over the late Quaternary; studies of these shifts may yield insights into likely biotic responses to contemporary warming. Here, we review research undertaken over the past decade investigating the response of Neotoma (woodrats) body size and distribution to climate change over the late Quaternary (the last 40,000 years). By integrating information from woodrat palaeomiddens, historical museum specimens and field studies of modern populations, we identify potential evolutionary responses to climate change occurring over a variety of...
thumbnail
These data provide current and future projected habitat distribution models for four shrub species: beaked hazelnut (Corylus cornuta), Oregon grape (Mahonia aquifolium), salal (Gaultheria shallon), and black huckleberry, (Vaccinium membranaceum), as well as a current projected habitat distribution model for evergreen huckleberry (Vaccinium ovatum). Each raster file represents the projected habitat suitability for each shrub species, climate scenario, and time period. Files are named according to the species (coco = Corylus cornuta, maaq = Mahonia aquifolium, gash = Gaultheria shallon, vame = Vaccinium membranaceum, and vaov2 = Vaccinium ovatum), then the RCP pathway (none for current, 'low' for RCP 4.5, and 'high'...
thumbnail
Heat load, a unitless value from 0 (low incident radiation) to around 1 (high incident radiation), is calculated using aspect, slope, and latitude (McCune and Dylan 2002). For the purposes of the exploration tool, the data are binned into 6 classes using Geometric Interval. Classes range from very low to very high and are designed to allow the classification of a polygon into its heat load types. McCune, B. and Keon, D., 2002, Equations for potential annual direct incident radiation and heat load: Journal of Vegetation Science, v. 13, no. 4, p. 603-606, https://doi.org/10.1111/j.1654-1103.2002.tb02087.x.
Aim The influence of anthropogenic climate change on organisms is an area of great scientific concern. Increasingly there is recognition that abrupt climate transitions have occurred over the late Quaternary; studies of these shifts may yield insights into likely biotic responses to contemporary warming. Here, we review research undertaken over the past decade investigating the response of Neotoma (woodrats) body size and distribution to climate change over the late Quaternary (the last 40,000 years). By integrating information from woodrat palaeomiddens, historical museum specimens and field studies of modern populations, we identify potential evolutionary responses to climate change occurring over a variety of...
thumbnail
Functional connectivity, quantified using landscape genetics, can inform conservation through the identification of factors linking genetic structure to landscape mechanisms. We used breeding habitat metrics, landscape attributes, and indices of grouse abundance, to compare fit between structural connectivity and genetic differentiation within five long-established Sage-Grouse Management Zones (MZ) I–V using microsatellite genotypes from 6,009 greater sage-grouse (Centrocercus urophasianus) collected across their range. We estimated structural connectivity using a circuit theory-based approach where we built resistance surfaces using thresholds dividing the landscape into “habitat” and “nonhabitat” and nodes were...
thumbnail
This dataset presents observations and measurements of riparian plant invasion, community composition, and environmental conditions at 238 bridge crossings in four western USA river basins: the Colorado Headwaters, upper/middle Rio Grande, upper Arkansas River, and South Platte River (281,946 square kilometers). The 238 sites are a stratified random sample of all bridge crossings in the river basins, with roughly equal numbers of sites in landscapes dominated by (1) urban and residential (developed) land-use, (2) agricultural (cultivated) land-use, and (3) undeveloped land cover. The dataset includes field observations of stem counts for three non-native riparian woody plant taxa (Tamarix ramosissima x T. chinensis...
thumbnail
"Vector Ruggedness Measure (VRM) measures terrain ruggedness as the variation in three-dimensional orientation of grid cells within a neighborhood. Vector analysis is used to calculate the dispersion of vectors normal (orthogonal) to grid cells within the specified neighborhood. This method effectively captures variability in slope and aspect into a single measure. Ruggedness values in the output raster can range from 0 (no terrain variation) to 1 (complete terrain variation). Typical values for natural terrains range between 0 and about 0.4. VRM was adapted from a method first proposed by Hobson (1972). VRM appears to decouple terrain ruggedness from slope better than current ruggedness indices, such as TRI or...
A new compilation of pollen and packrat midden data from western North America provides a refined reconstruction of the composition and distribution of biomes in western North America for today and for 6000 and 18,000 radiocarbon years before present (14C yr bp). Modern biomes in western North America are adequately portrayed by pollen assemblages from lakes and bogs. Forest biomes in western North America share many taxa in their pollen spectra and it can be difficult to discriminate among these biomes. Plant macrofossils from packrat middens provide reliable identification of modern biomes from arid and semiarid regions, and this may also be true in similar environments in other parts of the world. However, a...
Aim The geographical extent and climatic tolerances of one- and two-needled pinyon pines (Pinus subsect. Cembroides) are the focus of questions in taxonomy, palaeoclimatology and modelling of future distributions. The identification of these pines, traditionally classified by one- versus two-needled fascicles, is complicated by populations with both one- and two-needled fascicles on the same tree, and the description of two more recently described one-needled varieties: the fallax-type and californiarum-type. Because previous studies have suggested correlations between needle anatomy and climate, including anatomical plasticity reflecting annual precipitation, we approached this study at the level of the anatomy...
thumbnail
Conserving genetic connectivity is fundamental to species persistence, yet rarely is made actionable into spatial planning for imperiled species. Climate change and habitat degradation have added urgency to embrace connectivity into networks of protected areas. Our two-step process integrates a network model with a functional connectivity model, to identify population centers important to maintaining genetic connectivity then to delineate those pathways most likely to facilitate connectivity thereamong for the greater sage-grouse (Centrocercus urophasianus); a species of conservation concern ranging across eleven western U.S. states and into two Canadian provinces. This replicable process yielded spatial action...
thumbnail
"Vector Ruggedness Measure (VRM) measures terrain ruggedness as the variation in three-dimensional orientation of grid cells within a neighborhood. Vector analysis is used to calculate the dispersion of vectors normal (orthogonal) to grid cells within the specified neighborhood. This method effectively captures variability in slope and aspect into a single measure. Ruggedness values in the output raster can range from 0 (no terrain variation) to 1 (complete terrain variation). Typical values for natural terrains range between 0 and about 0.4. VRM was adapted from a method first proposed by Hobson (1972). VRM appears to decouple terrain ruggedness from slope better than current ruggedness indices, such as TRI or...
thumbnail
Aim The recent concern that quaking aspen (Populus tremuloides Michx.) has been declining in parts of western North America due to fire suppression is largely based on trends during the latter part of the 20th century. The aim of the current study was to compare the extent of aspen in the modern landscape with its extent in the late 19th century prior to fire suppression, and to assess the effects of elevation, late-19th century fires, and pre-fire forest composition on the successional status of aspen. Location North-west Colorado, USA. Methods We used a georeferenced 1898 map and modern maps to examine trends in aspen dominance since the late 19th century in a 348,586 ha area of White River and Routt National...
Pacific trout Oncorhynchus spp. in western North America are strongly valued in ecological, socioeconomic, and cultural views, and have been the subject of substantial research and conservation efforts. Despite this, the understanding of their evolutionary histories, overall diversity, and challenges to their conservation is incomplete. We review the state of knowledge on these important issues, focusing on Pacific trout in the genus Oncorhynchus. Although most research on salmonid fishes emphasizes Pacific salmon, we focus on Pacific trout because they share a common evolutionary history, and many taxa in western North America have not been formally described, particularly in the southern extent of their ranges....


map background search result map search result map Influences of infrequent fire, elevation and pre-fire vegetation on the persistence of quaking aspen (Populus tremuloides Michx.) in the Flat Tops area, Colorado, USA Distribution of Sagebrush and Associated Shrub-steppe Habitats in Western North America Western United States 30m Heatload Values Genetic and functional connectivity data for greater sage-grouse across the species range generated 2005–2015 (ver. 2.0, December 2022) Western US Ruggedness Reclassified into 6 Classes Western United States 30m Raw Heatload Values Western United States Ruggedness Raw Values Woody riparian invasive plant presence, stem density, and rank dominance and environmental conditions in 2012 at 238 bridge crossings in the Colorado Headwaters, upper/middle Rio Grande, upper Arkansas, and South Platte River Basins, USA Genetic data and genetic network attributes for rangewide Greater Sage-grouse network constructed in 2018 (ver. 2.0, December 2022) Microsatellite data, boundaries of subpopulation centers, and estimated effective migration for greater sage-grouse collected in western North America between 1992 and 2015 (ver. 2.0, December 2022) High-resolution maps of historical and 21st century ecological drought metrics using multivariate matching algorithms for drylands of western U.S. and Canada High-resolution maps of historical and 21st century soil temperature and moisture data using multivariate matching algorithms for drylands of western U.S. and Canada Habitat suitability models for understory shrubs of western North America Greater sage-grouse network-prioritized functional connectivity cumulative current map (raster) Influences of infrequent fire, elevation and pre-fire vegetation on the persistence of quaking aspen (Populus tremuloides Michx.) in the Flat Tops area, Colorado, USA Woody riparian invasive plant presence, stem density, and rank dominance and environmental conditions in 2012 at 238 bridge crossings in the Colorado Headwaters, upper/middle Rio Grande, upper Arkansas, and South Platte River Basins, USA Genetic and functional connectivity data for greater sage-grouse across the species range generated 2005–2015 (ver. 2.0, December 2022) Genetic data and genetic network attributes for rangewide Greater Sage-grouse network constructed in 2018 (ver. 2.0, December 2022) Microsatellite data, boundaries of subpopulation centers, and estimated effective migration for greater sage-grouse collected in western North America between 1992 and 2015 (ver. 2.0, December 2022) Greater sage-grouse network-prioritized functional connectivity cumulative current map (raster) Distribution of Sagebrush and Associated Shrub-steppe Habitats in Western North America Western United States 30m Raw Heatload Values Western United States 30m Heatload Values Western United States Ruggedness Raw Values Western US Ruggedness Reclassified into 6 Classes High-resolution maps of historical and 21st century ecological drought metrics using multivariate matching algorithms for drylands of western U.S. and Canada High-resolution maps of historical and 21st century soil temperature and moisture data using multivariate matching algorithms for drylands of western U.S. and Canada Habitat suitability models for understory shrubs of western North America