Implications Of Decade Time Scale Arctic Plant Community Change On Ecosystem Function

• Main Author: Lara, Mark Jason
• Format: Text
• Language: English
• Published: ScholarWorks@UTEP 2012
• Subjects: arctic; carbon; herbivory; methane; plant community change; tundra; Biogeochemistry; Climate; Ecology and Evolutionary Biology; Environmental Indicators and Impact Assessment; Arctic; Baffin Island; Canada; Baffin; Barrow; Climate change; International Polar Year; permafrost; Tundra; Alaska
• Online Access: https://scholarworks.utep.edu/open_etd/1861; https://scholarworks.utep.edu/cgi/viewcontent.cgi?article=2860&context=open_etd

Almost half the global soil organic carbon pool is found in northern high latitudes. The majority of this soil carbon is stored in a greenhouse inert state within permafrost. As pronounced warming of high northern latitudes ensues, there is a strong likelihood that this substantial soil organic carbon pool will be mobilized to the atmosphere where it is likely to positively enhance greenhouse warming. Modeling studies suggest this positive feedback could alter future climate states of the Arctic and the globe, and affect how humans may need to adapt to climate change. Accordingly, understanding the patterns and controls and the fate and transport of carbon in arctic terrestrial ecosystems has become well recognized as a research priority. This dissertation focuses on improving knowledge of decade-time scale plant community change and its impact on ecosystem function (i.e. biogeochemical cycling, and energy balance) in select sites throughout the North American Arctic. The studies presented largely take advantage of historic research activities conducted between the late 1950's and mid-1970s that have been resampled to assess change in ecosystem structure (i.e. makeup of plant species and abundance) and ecosystem function. The overarching goal of this dissertation is to determine how ecosystem function has changed in central Baffin Island, Canada, and in northern Alaska near Barrow in response to changes in climate, herbivory, nutrient availability, and plant community change over the past 30-60 years. In collaboration with Dr. Patrick J. Webber, this International Polar Year Back to the Future (BTF) project's primary objective was to determine how structure and function of high latitude arctic terrestrial ecosystems have changed over the past 25 or more years. At two sites, Baffin Island Canada, and Barrow Alaska, we used newly developed multivariate-geostatistical analytical procedure to asses change in ecosystem function over time. At our site in central Baffin Island, the greatest change in ecosystem function ...