DISSERTATION RESEARCH: Vegetation Effects on Nitrogen Cycling Hotspots in an Alpine-Subalpine Ecosystem

University Of Colorado At Boulder, Boulder CO

Investigators

Abstract

By burning fossil fuels and using nitrogen fertilizers, humans have doubled the global rate of nitrogen inputs to the atmosphere and natural ecosystems. These higher nitrogen inputs contribute to a multitude of environmental problems including air pollution, acid rain, climate change, higher abundance of invasive species, and biodiversity loss. To aid in understanding and managing these environmental problems, researchers have developed a detailed understanding of how nitrogen is processed in ecosystems based on small-scale plot-based measurements. While forming an important foundation, these small-scale measurements may not be representative of whole landscapes, especially in mountains. In this study, the investigators work toward a landscape-scale understanding of nitrogen cycling in an alpine-subalpine ecosystem. The research seeks to locate hotspots (unusually active areas) of nitrogen cycling within an alpine-subalpine ecosystem on Niwot Ridge in the southern Rocky Mountains, near the Denver metropolitan region. The research will address the relative roles of biological and non-biological factors in controlling nitrogen cycling rates. To accomplish these goals, the investigators will measure nitrogen cycling rates across the landscape in conjunction with field-collected and remotely-sensed data that describe physical, chemical, and biological conditions. This research will contribute to: (1) basic knowledge of variation in nitrogen cycling rates across diverse landscapes; (2) information for land management agencies responsible for setting limits on human nitrogen emissions that influence natural resources in mountain ecosystems; and (3) development of new methods for ecological measurements at larger spatial scales.