High elevation recreation presents a complex dimension to the management of mountain ecosystems. Results of our recent economic study indicate that recreators place approximately four times the value on high elevation recreation than on "typical" mountain recreation experiences. These findings imply that there are limited substitutes for high elevation recreation, and a high demand for such experiences could tax the environmental carrying capacity of the fragile tundra.
Relative timing and magnitude of response by plants, microbes and soil fauna to an experimental precipitation event on the Shortgrass Steppe L
A key climatic feature of the Shortgrass Steppe is the summertime pattern of moderate to large precipitation events, separated by weeks of hot, dry conditions. These precipitation events have potential to revive plants, microbes and soil fauna that became less active in the intervening dry period, and thus structure ecosystem-scale patterns including net carbon exchange.
The Shortgrass Steppe (SGS) LTER project studies an ecosystem that has persisted under a regime of semi-arid extremes, with high inter- and intra-annual variability in precipitation and temperature. The 340 mm of annual precipitation falls primarily during spring rainstorms over several days as well as during a period of summer rains from more localized thunderstorms. Further, the system is well-adapted both to grazing by large herbivores and to smaller-scale disturbances caused by animals like prairie dogs.
What mathematical skills, particularly in the area of reasoning about proportions, rate of change, and rate of growth are needed for a high school graduate to effectively use knowledge and tools from environmental science as an informed citizen in a democratic society? What are the quantitative reasoning stepping stones from elementary school through high school that might help develop this key to environmental science literacy?
Humans make decisions daily that impact biodiversity, and it is essential that citizens understand the implications of these decisions. Yet, ecological systems are extremely complex, with many details still being discovered. Our challenge is to identify the underlying principles and concepts governing the distribution of organisms, and then communicate these details to students in a way that influences their citizenship decisions as participants in local and global communities.
Community responses of ground-dwelling beetles (Tenebrionidae) to a gradient of traditional and manipulated grazing in shortgrass steppe
Responses of plants to grazing are better understood, and more predictable, than those of consumers in grassland ecosystems of the North American Great Plains. In 2003, we began a large-scale, replicated experiment to examine the effects of grazing on ground-dwelling beetles (Tenebrionidae), an important consumer community in shortgrass steppe of north-central Colorado, USA. We sought to determine whether modifications of the intensity and seasonality of livestock grazing alter the structure and diversity of beetle communities compared to traditional grazing regimes.
Measuring Ammonia Emissions along the Front Range: Towards an Understanding of Nitrogen Deposition in Rocky Mountain National Park
Wet deposition of ammonium in Rocky Mountain National Park (RMNP) and along the eastern slope of the Rocky Mountains has reached a “critical load” where negative impacts on alpine ecosystems are evident. Results from the recently completed Rocky Mountain Atmospheric Nitrogen and Sulfur Study (RoMANS) suggest that many different sources are contributing to atmospheric nitrogen deposition in the park. Sources include long distance transport from western states, regional contributions from agricultural and urban sites in Colorado, and local emissions from soils within the park.
Due to fragmentation, where there were once contiguous populations of grasslands, core and edge populations remain, often times separated by large distances and located in different climates. Previous research has largely overlooked edge populations and focused on dominant species in core populations. The purpose of this study is to compare core and edge populations of two dominant C4 grasses, Bouteloua gracilis and Andropogon gerardii, in a reciprocal transplant experiment.
Wildlife face ever-increasing threats from emerging pathogens, many that also cause disease in humans. Genetic diversity plays a central role in buffering populations against the effects of parasites and pathogens. The ability to isolate genes related directly to disease susceptibility and understanding how those genes evolve is important for designing successful and cost-effective conservation programs. We are investigating the relationship between diversity in six immune system genes and the parasite community of black-tailed prairie dogs.
According to the latest IPCC report, global climate change models are predicting an increase in the variability and intensity of extreme weather events, such as drought, in semi-arid regions. Semi-arid grasslands, or shortgrass-steppe, are among the most responsive ecosystems to global climate change. Therefore it is critical to determine the underlying mechanisms of their responses to scenarios like drought and how these mechanisms vary across space and time.