23 research outputs found
Development of Future Habitat Suitability Models for the Swift fox (Vulpes velox) in the American Southwest
The Swift fox (Vupes velox) is a habitat specialist species of short or mixed grass prairie. We used bioclimatic envelope models and habitat suitability models under three future climate scenarios (based on CO2 emission rates) from "www.climatewizard.org":http://www.climatewizard.org to fit species distribution models, using the maximum entropy method. Current suitable habitat for the swift fox covers an area of 161,984 km2. Under the future climate scenarios the habitat decreases by 27% in the low emission scenario, 63% for medium emissions, and 53% in the high emissions scenario. This decrease in suitable habitat corresponded to an overall decrease in total grassland landcover. The current total area of grassland is 423,440 km2. Under the future climate scenarios the grassland decreased by 12% in the low emissions scenario, 24% for medium emissions, and 16% in the high emissions scenario
Applying Biodiversity Metrics as Surrogates to a Habitat Conservation Plan
Unabated urbanization has led to environmental degradation and subsequent biodiversity loss across the globe. As an outcome of unmitigated land use, multi-jurisdictional agencies have developed land use plans that attempt to protect threatened or endangered species across selected areas by which some trade-offs between harm to species and additional conservation approaches are allowed among the partnering organizations. Typical conservation plans can be created to focus on single or multiple species, and although they may protect a species or groups of species, they may not account for biodiversity or its protection across the given area. We applied an approach that clustered deductive habitat models for terrestrial vertebrates into metrics that serve as surrogates for biodiversity and relate to ecosystem services. In order to evaluate this process, we collaborated with the partnering agencies who are creating a Multi-Species Habitat Conservation Plan in southern California and compared it to the entire Mojave Desert Ecoregion. We focused on total terrestrial vertebrate species richness and taxon groupings representing amphibians, birds, mammals, and reptiles, and two special status species using the Normalized Index of Biodiversity (NIB). The conservation planning area had a lower NIB and was less species rich than the Mojave Desert Ecoregion, but the Mojave River riparian corridor had a higher NIB and was more species-rich, and while taxon analysis varied across the geographies, this pattern generally held. Additionally, we analyzed desert tortoise (Gopherus agassizii) and desert kit fox (Vulpes macrotis arsipus) as umbrella species and determined that both species are associated with increased NIB and large numbers of species for the conservation area. Our process provided the ability to incorporate value-added surrogate information into a formal land use planning process and used a metric, NIB, which allowed comparison of the various planning areas and geographic units. Although this process has been applied to Apple Valley, CA, and other geographies within the U.S., the approach has practical application for other global biodiversity initiatives
Multispectral and Texture Feature Application in Image-Object Analysis of Summer Vegetation in Eastern Tajikistan Pamirs
We tested the Moment Distance Index (MDI) in combination with texture features for the summer vegetation mapping in the eastern Pamir Mountains, Tajikistan using the 2014 Landsat OLI (Operational Land Imager) image. The five major classes identified were sparse vegetation, medium-dense vegetation, dense vegetation, barren land, and water bodies. By utilizing object features in a random forest (RF) classifier, the overall classification accuracy of the land cover maps were 92% using a set of variables including texture features and MDI, and 84% using a set of variables including texture but without MDI. A decrease of the Kappa statistics, from 0.89 to 0.79, was observed when MDI was removed from the set of predictor variables. McNemar’s test showed that the increase in the classification accuracy due to the addition of MDI was statistically significant (p < 0.05). The proposed method provides an effective way of discriminating sparse vegetation from barren land in an arid environment, such as the Pamir Mountains
Spatial Identification of Statewide Areas for Conservation Focus in New Mexico: Implications for State Conservation Efforts
Landscape scale conservation planning efforts have been in place for the past several decades to maintain biodiversity. Objectives of past efforts have been to identify areas to create reserves based on species diversity, land ownership, and landscape context. Risk analysis has not often been included in these spatial analyses. Datasets such as the Southwest Regional Gap Analysis (SWReGAP) are now available as are processes that allow risk analysis to be viewed in a spatial context in relations to factors that affect habitats over broad scales. We describe a method to include four spatial datasets to provide coarse scale delineation on areas to focus conservation including species numbers, key habitats, land management and factors that influence habitats. We used the SWReGAP management status dataset to identify management categories for long-term intent of management for biodiversity. The New Mexico Department of Game and Fish identified a set of 290 Species of Greatest Conservation Need (SGCN). Species occurrences for these species were associated with hydrologic unit codes from the National Hydrography Dataset (NHD). Key habitats were identified by using the SWReGAP land cover dataset and NHD derivatives. Factors that influence habitats were identified and scored for 89 land cover types and 23 aquatic habitats identified by the NMDGF. Our final model prioritizes landscapes that are within key habitats, have high numbers of terrestrial and aquatic Species of Greatest Conservation Need taxa, may be potentially altered by multiple effects that influence habitats, and lack long-term legally-binding management plans protecting them from anthropogenic degradation. Similar to other efforts, riparian and aquatic habitats were identified as the most important for conservation. This information may be displayed spatially, allowing land managers and decision makers to understand the ecological context where multiple effects of potential factors may influence some habitats greater than others, and repeat process with CWCS revisions
Evaluating Biodiversity Metric Response to Forecasted Land Use Change in the Northern Rio Grande Basin
The effects of future land use change on arid and semi-arid watersheds in the American Southwest have important management implications. Seamless, national-scale land-use-change scenarios for developed land were acquired from the US Environmental Protection Agency Integrated Climate and Land Use Scenarios (lCLUS) project and extracted to fit the Northern Rio Grande River Basin, New Mexico relative to projections of housing density for the period from 2000 through 2100. Habitat models developed from the Southwest Regional Gap Analysis Project were invoked to examine changes in wildlife habitat and biodiversity metrics using five ICLUS scenarios. The scenarios represent a US Census base-case and four modifications that were consistent with the different assumptions underlying the A1, A2, B1, and B2 Intergovernmental Panel on Climate Change global greenhouse gas emission storylines. Habitat models for terrestrial vertebrate species were used to derive metrics reflecting ecosystem services or biodiversity aspects valued by humans that could be quantified and mapped. Example metrics included total terrestrial vertebrate species richness, bird species richness, threatened and endangered species, and harvestable species (e.g., waterfowl, big game). Overall, the defined scenarios indicated that the housing density and extent of developed lands will increase throughout the century with a resultant decrease in area for all species richness categories. The A2 Scenario, in general, showed greatest effect on area by species richness category. The integration of the land use scenarios with biodiversity metrics derived from deductive habitat models may prove to be an important tool for decision makers involved in impact assessments and adaptive planning processes
Monitoring Heifer Grazing Distribution at the Valles Caldera National Preserve
The Rangelands archives are made available by the Society for Range Management and the University of Arizona Libraries. Contact [email protected] for further information.Migrated from OJS platform March 202
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Piñon-Juniper Woodland Use by Cattle in Relation to Weather and Animal Reproductive State
We conducted a study to determine the role of piñon-juniper (PJ) woodland in providing shelter for cattle at a site in central New Mexico. Positions of 16 cows, 8 pregnant or nursing (PN) and 8 nonpregnant-nonlactating (NPNL), grazing a PJ woodland-grass steppe mosaic were recorded every 5 min by Global Positioning System during late winter and early spring in 2004 and 2005 (eight different cows in each year). Hourly weather variables were also recorded at a weather station located at our research site. Weekly fecal samples were collected from all collared cattle (n = 16) to determine botanical composition of diets. Decreasing air temperatures, increasing relative humidity, winds out of the northwest (all of which are associated with heat loss), and increasing short-term thermal stress were associated with a detectable (P<0.05) increase in PJ-woodland preference of PN and NPNL cows. Days to/from calving date was a significant predictor of PJ-woodland preference of PN cows (P < 0.05), which showed highest PJ-woodland preference on the day before or immediately after calving date. Preference for PJ woodland by all cows, averaged across the study period, increased with the increasing proportion of days with cold short-term thermal stress (P<0.01) and decreasing availability of open shortgrass forage (P<0.01). PN and NPNL cows exhibited detectably different grazing patterns (P=0.01). PN cows explored smaller areas (P<0.01) and traveled shorter distances (P = 0.053) than NPNL counterparts in any given day. Winterfat (Krascheninnikova lanata [Pursh] A. Meeuse Smit) was the only plant species analyzed that was detectably more abundant (P = 0.05) in NPNL vs. PN diets, particularly during the week surrounding calving in 2005. Our data suggest that PJ woodland with abundant understory can play an important role in providing shelter for nursing or dry cattle during winter, particularly in years when forage availability is scarce. The Rangeland Ecology & Management archives are made available by the Society for Range Management and the University of Arizona Libraries. Contact [email protected] for further information.Migrated from OJS platform August 202