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Grantee Research Project Results

Grantee Research Project Results

An Integrated Field Investigation of the Interactions Between Climate Change and Ecosystem Structure and Function

EPA Grant Number: U915000
Title: An Integrated Field Investigation of the Interactions Between Climate Change and Ecosystem Structure and Function
Investigators: Dunne, Jennifer A.
Institution: University of California - Berkeley
EPA Project Officer: Jones, Brandon
Project Period: January 1, 1996 through January 1, 1999
Project Amount: $102,000
RFA: STAR Graduate Fellowships (1996)
Research Category: Academic Fellowships , Ecological Indicators/Assessment/Restoration , Fellowship - Ecology and Ecosystems

Description:

Objective:

The objective of this research project is to compare and synthesize results from an ongoing ecosystem warming experiment with measurements of vegetation, nutrient, and microclimate dynamics 1) along a natural climatic gradient, and 2) within a new set of warming-related climate manipulations along the gradient. In particular, I am examining the interactions of climate warming and ecosystem structure and dynamics within an ecotone of Rocky Mountain subalpine meadow and Great Basin shrub steppe.

Approach:

I am conducting research in subalpine meadows near the Rocky Mountain Biological Laboratory in the upper East River Valley of Gunnison County, CO. One site (the "warming meadow") was established in 1991, and has a set of five control plots and five manipulated plots with overhead heaters that increase downward IR flux as predicted under doubled CO2. The heaters result in earlier snowmelt, longer growing season, 1-2 degrees C soil warming, and 10-25% percent soil drying during the growing season. In 1995, I established three additional sites along an elevational gradient centered near the warming meadow. Each of the new sites has five control plots and five manipulated plots in which snowmelt is accelerated via shoveling. Timing of snowmelt differs naturally among the gradient sites to the degree that it differs between control and manipulated plots at each of the four sites (about 1-2 weeks). In each of the plots from 1996-1998, I monitored dynamics of the following parameters during the snow -free growing season (mid May to mid September): plant reproductive phenology; aboveground biomass of shrubs, forbs, and graminoids; plant community composition and shrub seedling establishment; and soil inorganic nitrogen stocks, in situ net nitrogen mineralization rates, and C:N ratios. In addition, each plot has soil moisture and temperature data sets that calculate year round and every 2 hours at 12 and 25 cm.

Supplemental Keywords:

fellowship, subalpine meadows, ecosystem, gradient, climate, climate warming, ecosystem structure and dynamics, snowmelt, climate change, ecosystem function., RFA, Scientific Discipline, Air, ENVIRONMENTAL MANAGEMENT, Ecosystem Protection/Environmental Exposure & Risk, Environmental Chemistry, Ecosystem/Assessment/Indicators, climate change, Economics, Atmospheric Sciences, Ecological Risk Assessment, Atmosphere, Ecological Indicators, Risk Assessment, environmental monitoring, anthropogenic stress, ecological exposure, climate change impact, meteorology, ozone, global change, economic models, socioeconomic indicators, carbon dioxide, microclimate model, environmental stressors, landscape characterization, forest resources, forest productivity model, ecological models, climate variability, Global Climate Change, climatic models

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The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.

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