Find research datasets worth reusing

Multi-temporal TM-NDVI Vectors at Rodent Webs from the Sevilleta National Wildlife Refuge, New Mexico (1984-1993)

This database contains mean NDVI values for 200 m diameter circles encompassing Rodent Webs on the Sevilleta National Wildlife Refuge (NWR), for 21 Landsat TM scene dating from 1984 to 1993. These NDVI vectors were generated as part of cooperative project between the Sevilleta LTER and the Indian Health Service, to study the 1992 Hantavirus outbreak.

Coyote Population Densities at the Sevilleta National Wildlife Refuge, New Mexico (1992-2004)

This study measured the population dynamics of coyotes in the grasslands and creosote shrublands of McKenzie Flats, Sevilleta National Wildlife Refuge. The study was begun in January, 1992, and continued quarterly each year. Coyotes were sampled via scat counts along the roads of McKenzie Flats during winter, spring, summer, and fall of each year. The entire road transect was 21.5 miles in length. Scat counts over a week period (number of scats/mile/day) in each season along the roads were used to calculate the densities of coyotes (number of coyotes per square kilometer). Results from 1992 to 2002 indicated that autumn was the peak density period of the year, with generally steady declines through the year until the following autumn. Coyote populations appeared to fluctuate seasonally, but remained relatively stable at 0.27 +/- 0.03 (SE) coyotes per km2 during summer periods (this likely represents the "breeding pair" density, during which coyote pairs have set up territories and are raising young, but the pups have not as yet joined the parents in foraging activities).

openOpenJan 2014View details →

Rabbit Population Densities at the Sevilleta National Wildlife Refuge, New Mexico (1992-2004)

This study measured the population dynamics of black-tail jackrabbits (Lepus californicus) and desert cottontail rabbits (Sylvilagus auduboni) in the grasslands and creosote shrublands of McKenzie Flats, Sevilleta National Wildlife Refuge.Â The study was begun in January, 1992, and continued quarterly each year.Â Rabbits were sampled via night-time spotlight transect sampling along the roads of McKenzie Flats during winter, spring, summer, and fall of each year.Â The entire road transect was 21.5 miles in length. Measurements of perpendicular distance of each rabbit from the center of the road were used to estimate densities (number of rabbits per square kilometer) via Program DISTANCE.Â Results from 1992 to 2002 indicated that spring was the peak density period of the year, with generally steady declines through the year until the following spring. Evidence of a long-term "cycle" (e.g., the 11 year cycle reported for rabbits in the Great Basin Desert) did not appear in the Sevilleta rabbit populations.

Plant Litter Decomposition at the Sevilleta National Wildlife Refuge, New Mexico (1990-1998)

The long-term goal of the decomposition study was to document the effects of climate variation on decomposition of major plant litter-types. The project began in 1989 and underwent changes of locations and litter types. The long-term litter types included black grama, Indian rice grass, juniper, and creosote. Â Mass loss of the litter types can be compared to precipitation and other meteorological factors obtained at nearby locations.

Effects of Kangaroo Rats on Plant Species Dominance in a Chihuahuan Desert Grassland at the Sevilleta National Wildlife Refuge, New Mexico (1988)

Our objective was to evaluate the effects of burrowing activities by banner-tail kangaroo rats (Dipodomys spectabilis Merriam) on plant community structure and species dominance for two patch types at an ecotone between shortgrass steppe and desert grasslands in New Mexico, USA. Ten mounds produced by kangaroo rats were selected in patches dominated by Bouteloua gracilis (the dominant in shortgrass steppe communities) and ten mounds were selected in patches dominated by Bouteloua eriopoda (the dominant in Chihuahuan desert grasslands). Plant cover and density by species were sampled from three locations associated with each mound: the mound proper, the edge of the mound in the transition area, and the off-mound vegetation. Similar cover of B. eriopoda for the edges of mounds in both patch types indicates the ability of this species to respond to animal disturbances regardless of the amount of cover in the surrounding undisturbed vegetation. By contrast, cover of B. gracilis was low for all mounds and mound edges in patches dominated by this species. Much higher cover of B. eriopoda on mound edges compared to the undisturbed vegetation in B. gracilis- dominated patches indicates that kangaroo rats have important positive effects on this species. Lower cover of perennial grasses and higher cover of forbs, shrubs, and succulents on the edges of mounds in B. eriopoda - dominated patches compared to patches dominated by B. gracilis indicate the importance of surrounding vegetation to plant responses on disturbed areas. Our results show that kangaroo rats have important effects on both species dominance and composition for different patch types, and may provide a mechanism for small-scale dominance patterns at an ecotonal boundary; thus providing further support for their role as keystone species in desert grasslands.

openOpenJan 2020View details →

Rainfall Manipulation Study Vegetation Data from the Chihuahuan Desert Grassland and Creosote Shrubland at the Sevilleta National Wildlife Refuge, New Mexico (2003-2011)

The overall goal of the rainfall manipulation project is to understand the coupled ecological and hydrological responses of a grassland, shrubland and a mixed grass-shrub vegetation community to extended periods of increased or decreased rainfall. Rainfall manipulation plots have been established in each of these three vegetation communities in the Five Points area of Sevilleta National Wildlife Refuge. In each vegetation community, three control plots, three drought treatment plots, and three water addition plots have been installed, each approximately 10 x 15 m in size. In each plot, vertical profiles of soil moisture probes have been installed under each cover type (canopy and interspace in grassland and shrubland; grass canopy, shrub canopy and interspace at the ecotone (mixed grass-shrub) site). The probes measure differences in infiltration and soil water content and potential associations with these different cover types. In addition, TDR probes have been installed diagonally in each cover type to integrate the water content of the top 15 cm of soil. Each plot contains 18, 1m2 quads made up of 6, 1m2 quads along each of the 3 transects located across each plot. Each spring and fall, the following parameters are measured in every quad: live plant cover, height, and abundance by species; dead plant cover; soil cover; litter cover; and rock cover. Data collection began in the drought and control plots in the spring of 2002. Data collection began in the water addition plots in the spring of 2004.In the grassland and shrubland communities, all nine currently established plots are located together. The three drought plots were located under a single large roof with a 0.5 m path separating each plot (drought treatments ended in 2006). The control plots and water addition plots are similarly grouped, but without the shelter structure. In the ecotone community, the plots are in three groups; each group is comprised of one drought plot, one water addition plot, and one

openOpenFeb 2011View details →

Burn Exclosure Rodent Population Study at the Sevilleta National Wildlife Refuge, New Mexico (1991-1993)

Small mammal densities were estimated from small mammal recapture data in burned and unburned grassland.

The Effect of Kangaroo-Rat Activity on Plant Species Composition at the Sevilleta National Wildlife Refuge, New Mexico (1999)

Our objective was to evaluate the effects of kangaroo rat mounds on species diversity and composition at a semiarid-arid grassland ecotone. We expected that source populations of plants occurring on kangaroo rat mounds have important influences on the species composition of vegetation at the landscape scale, and that these influences differ by grassland type. Our study was conducted at the Sevilleta LTER in New Mexico, where a grassland type dominated by Bouteloua gracilis, a shortgrass steppe species, and a grassland type dominated by B. eriopoda, a desert grassland species, meet to form patches across the landscape. Four 0.4 ha plots were sampled for species diversity and composition in a regular 7m x 7m grid in each grassland type. Kangaroo rat mounds were also mapped and sampled for vegetation measures in four areas of 1.6 ha in each type. The landscape scale abundance of many subordinate species was increased significantly by populations occurring on kangaroo rat mounds in both grassland types. However, the area affected by the burrowing activity of kangaroo rats was twice as large in the B. eriopoda dominated grassland type. Furthermore, dominant plants on mounds in the B. eriopoda type were also abundant in off-mound areas whereas dominant plants on mounds in the B. gracilis type were not as abundant off-mound. These results indicate that the presence of mounds in the B. gracilis dominated type is creating islands of plant communities that are distinct from the rest of the grassland. Therefore, the occurrence of certain plant species in this grassland type may be intimately associated with the disturbance regime at this ecotone. This study demonstrates that effects of small burrowing animals may facilitate the coexistence of species at this ecotone.

Soil Characteristics Following a Lightning-Initiated Fire at MacKenzie Flats, Sevilleta National Wildlife Refuge, New Mexico (1998)

We evaluated soil characteristics after a lightning-initiated fire. Following the fire in July 1998, 25 experimental plots were established on the eastern edge of MacKenzie Flats at the Sevilleta National Wildlife Refuge. Ten of these plots were located in a Bouteloua gracilis (blue grama)-dominated site, while 15 were established in another area dominated by Bouteloua eriopoda (black grama). All plots were oriented along a topographic gradient that ran in an east-west direction. At three topographic locations within each plot, soil samples were taken at two depths from an area covered by perennial grass as well as an area devoid of vegetation. Soil samples were collected in July 1998 and analyzed for moisture content and soil texture.

Post-Fire Response of Perennial Grass Communities at McKenzie Flats, Sevilleta National Wildlife Refuge, New Mexico (1998 and 2001)

We evaluated the effects of a lightning-initiated fire on responses of vegetation communities. Following a fire in July 1998, 25 experimental plots were established on the eastern edge of MacKenzie Flats at the Sevilleta National Wildlife Refuge. Ten of these plots were located in a Bouteloua gracilis (blue grama)- dominated site, while 15 were established in another area dominated by Bouteloua eriopoda (black grama). We evaluated basal and aerial cover of all plant species at the community level using a vertical line point intercept method along transects within plots. Sampling was conducted immediately after the fire during the last week of July 1998, and again in September and October of 2001.

Post-Fire Responses of Perennial Grass Populations at McKenzie Flats, Sevilleta National WIldlife Refuge, New Mexico (1998 and 2001)

We evaluated the effects of a lightning-initiated fire on resprouting responses of perennial grasses at the population level. Following a fire in July 1998, 25 experimental plots were established on the eastern edge of MacKenzie Flats at the Sevilleta National Wildlife Refuge. Ten of these plots were located in a Bouteloua gracilis (blue grama)-dominated site, while 15 were established in an area dominated by Bouteloua eriopoda (black grama). We evaluated basal cover of perennial grasses in systematically positioned quadrats (subsamples) within plots immediately after the fire (last week of July 1998), and in September-October 2001.

Pino Gate Prairie Dog Study at the Sevilleta National Wildlife Refuge, New Mexico: Landscape Plot Lizard Data (2001-2002)

Livestock Exclosure Study: Plant Species Composition in a Chihuahuan Desert Grassland at the Sevilleta National Wildlife Refuge, New Mexico (2004-2007)

Grazing in grasslands creates changes in plant community structure. The magnitude of these changes depends on the productivity and the intensity of grazing. Low productivity grasslands coupled with high grazing intensity may lead to shrub encroachment in some aridland ecosystems. We examined the effects of cattle grazing in arid grassland at the Sevilleta LTER site in central New Mexico USA where cattle were removed in 1973 and an area just north of the Sevilleta LTER where grazing by cattle still occurs. At each site we measured plant species composition and cover in permanent plots in the spring and fall from 2004 to 2007. Quadrats were clipped annually to quantify aboveground standing crop to answer the following questions: 1) Does cattle grazing affect plant species composition and standing crop? 2) Does grazing alter community response to inter-annual climate variability? and 3) How does grazing impact the abundance of native grasses?

Livestock Exclosure Study: Aboveground Standing Crop from a Chihuahuan Desert Grassland at the Sevilleta National Wildlife Refuge, New Mexico (2005-2007)

Pino Gate Prairie Dog Study: Landscape-scale Vegetation Plot Data from the Sevilleta National Wildlife Refuge, New Mexico (1999-2002)

Prairie dogs (Cynomys spp.) and banner-tailed kangaroo rats (Dipodomys spectabilis) are considered keystone species of grassland ecosystems, and co-occur in the arid grasslands of the southwestern United States and in Mexico. Their keystone status is attributed primarily to the effects of their burrowing and foraging behavior, but they differ ecologically in several important respects. We studied the comparative functional roles of these species where they co-occur at the Sevilleta National Wildlife Refuge, New Mexico, focusing on their impacts on grassland vegetation. We found that vegetation cover, structure, and species richness varied across a gradient extending out from the mound centers, and these patterns differed between prairie dog and kangaroo rat mounds. Certain species and functional groups of plants associated differentially with mounds and landscape patches occupied by prairie dogs and banner-tailed kangaroo rats. Where both species co-occurred locally there was greater soil disturbance, more organic material from their feces, and higher activity of other animals. The overall effect of these rodents was to create a mosaic of different patches across the landscape such that their combined activities increased andscape heterogeneity and plant species richness. Our results demonstrate complementary effects of two co-occurring keystone species on their associated biotic communities.

Pino Gate Prairie Dog Study: Mound-scale Vegetation Plot Data from the Sevilleta National Wildlife Refuge, New Mexico (2000-2002)

Prairie dogs (Cynomys spp.) and banner-tailed kangaroo rats (Dipodomys spectabilis) are considered keystone species of grassland ecosystems, and co-occur in the arid grasslands of the southwestern United States and in Mexico. Their keystone status is attributed primarily to the effects of their burrowing and foraging behavior, but they differ ecologically in several important respects. We studied the comparative functional roles of these species where they co-occur at the Sevilleta National Wildlife Refuge, New Mexico, focusing on their impacts on grassland vegetation. We found that vegetation cover, structure, and species richness varied across a gradient extending out from the mound centers, and these patterns differed between prairie dog and kangaroo rat mounds. Certain species and functional groups of plants associated differentially with mounds and landscape patches occupied by prairie dogs and banner-tailed kangaroo rats. Where both species co-occurred locally there was greater soil disturbance, more organic material from their feces, and higher activity of other animals. The overall effect of these rodents was to create a mosaic of different patches across the landscape such that their combined activities increased landscape heterogeneity and plant species richness. Our results demonstrate complementary effects of two co-occurring keystone species on their associated biotic communities.

Pino Gate Prairie Dog Study: Landscape-scale Ground-Dwelling Arthropod Plot Data from the Sevilleta National Wildlife Refuge, New Mexico (2000-2001)

Keystone species have large impacts on community and ecosystem properties, and create important ecological interactions with other species. Prairie dogs (Cynomys spp.), and banner-tailed kangaroo rats (Dipodomys spectabilis) are considered keystone species of grassland ecosystems, and create a mosaic of unique habitats on the landscape. These habitats are known to attract a number of animal species, but little is known about how they affect arthropod communities. Our research evaluated the keystone roles of prairie dogs and kangaroo rats on arthropods at the Sevilleta National Wildlife Refuge in central New Mexico, USA. We evaluated the impacts of these rodents on ground-dwelling arthropod and grasshopper communities in areas where prairie dogs and kangaroo rats co-occurred compared to areas where each rodent species occurred alone. Our results demonstrate that prairie dogs and kangaroo rats have keystone-level impacts on these arthropod communities. Their burrow systems provided important habitats for multiple trophic and taxonomic groups of arthropods, and increased overall arthropod abundance and species richness on the landscape. Many arthropods also were attracted to the aboveground habitats around the mounds and across the landscapes where the rodents occurred. Detritivores, predators, ants, grasshoppers, and rare rodent burrow inhabitants showed the strongest responses to prairie dog and kangaroo rat activity. The impacts of prairie dogs and kangaroo rats were unique, and the habitats they created supported different assemblages of arthropods. Where both rodent species occurred together on the landscape, there was great habitat heterogeneity and increased arthropod diversity.

Pino Gate Prairie Dog Study: Mound-scale Ground-Dwelling Arthropod Plot Data from the Sevilleta National Wildlife Refuge, New Mexico (2000-2001)

Keystone species have large impacts on community and ecosystem properties, and create important ecological interactions with other species. Prairie dogs (Cynomys spp.) and banner-tailed kangaroo rats (Dipodomys spectabilis) are considered keystone species of grassland ecosystems,and create a mosaic of unique habitats on the landscape. These habitats are known to attract a number of animal species, but little is known about how they affect arthropod communities. Our research evaluated the keystone roles of prairie dogs and kangaroo rats on arthropods at the Sevilleta National Wildlife Refuge in central New Mexico, USA. We evaluated the impacts of these rodents on ground-dwelling arthropod and grasshopper communities in areas where prairie dogs and kangaroo rats co-occurred compared to areas where each rodent species occurred alone. Our results demonstrate that prairie dogs and kangaroo rats have keystone-level impacts on these arthropod communities. Their burrow systems provided important habitats for multiple trophic and taxonomic groups of arthropods, and increased overall arthropod abundance and species richness on the landscape. Many arthropods also were attracted to the aboveground habitats around the mounds and across the landscapes where the rodents occurred. Detritivores, predators, ants, grasshoppers, and rare rodent burrow inhabitants showed the strongest responses to prairie dog and kangaroo rat activity. The impacts of prairie dogs and kangaroo rats were unique, and the habitats they created supported different assemblages of arthropods. Where both rodent species occurred together on the landscape, there was greater habitat heterogeneity and increased arthropod diversity. there was great habitat heterogeneity and increased arthropod diversity.

Pino Gate Prairie Dog Study: Landscape-scale Grasshopper Plot Data from the Sevilleta National Wildlife Refuge, New Mexico (2000-2002)

Keystone species have large impacts on community and ecosystem properties, and create important ecological interactions with other species. Prairie dogs (Cynomys spp.) and banner-tailed kangaroo rats (Dipodomys spectabilis) are considered keystone species of grassland ecosystems, and create a mosaic of unique habitats on the landscape. These habitats are known to attract a number of animal species, but little is known about how they affect arthropod communities. Our research evaluated the keystone roles of prairie dogs and kangaroo rats on arthropods at the Sevilleta National Wildlife Refuge in central New Mexico, USA. We evaluated the impacts of these rodents on ground-dwelling arthropod and grasshopper communities in areas where prairie dogs and kangaroo rats co-occurred compared to areas where each rodent species occurred alone. Our results demonstrate that prairie dogs and kangaroo rats have keystone-level impacts on these arthropod communities. Their burrow systems provided important habitats for multiple trophic and taxonomic groups of arthropods, and increased overall arthropod abundance and species richness on the landscape. any arthropods also were attracted to the aboveground habitats around the mounds and across the landscapes where the rodents occurred. Detritivores, predators, ants, grasshoppers, and rare rodent burrow inhabitants showed the strongest responses to prairie dog and kangaroo rat activity. The impacts of prairie dogs and kangaroo rats were unique, and the habitats they created supported different assemblages of arthropods. Where both rodent species occurred together on the landscape, there was greater habitat heterogeneity and increased arthropod diversity.

Pino Gate Prairie Dog Study: Mound-scale Grasshopper Plot Data from the Sevilleta National Wildlife Refuge, New Mexico (2000-2001)

Keystone species have large impacts on community and ecosystem properties, and create important ecological interactions with other species. Prairie dogs (Cynomys spp.) and banner-tailed kangaroo rats (Dipodomys spectabilis) are considered keystone species of grassland ecosystems, and create a mosaic of unique habitats on the landscape. These habitats are known to attract a number of animal species, but little is known about how they affect arthropod communities. Our research evaluated the keystone roles of prairie dogs and kangaroo rats on arthropods at the Sevilleta National Wildlife Refuge in central New Mexico, USA. We evaluated the impacts of these rodents on ground-dwelling arthropod and grasshopper communities in areas where prairie dogs and kangaroo rats co-occurred compared to areas where each rodent species occurred alone. Our results demonstrate that prairie dogs and kangaroo rats have keystone-level impacts on these arthropod communities. Their burrow systems provided important habitats for multiple trophic and taxonomic groups of arthropods, and increased overall arthropod abundance and species richness on the landscape. Many arthropods also were attracted to the aboveground habitats around the mounds and across the landscapes where the rodents occurred. Detritivores, predators, ants, grasshoppers, and rare rodent burrow inhabitants showed the strongest responses to prairie dog and kangaroo rat activity. The impacts of prairie dogs and kangaroo rats were unique, and the habitats they created supported different assemblages of arthropods. Where both rodent species occurred together on the landscape, there was greater habitat heterogeneity and increased arthropod diversity.