EFFECTS OF SIMULATED CLIMATE CHANGE ON SOIL MICROBIAL DIVERSITY IN A BOREAL-DECIDUOUS FOREST ECOTONE

The purpose of this study is to determine the effects of artificial temperature and precipitation flux on soil microbial communities associated with sugar maple seedlings (Acer saccharum). This study is part of an ongoing project examining the growth of sugar maple seedlings in response to human-induced temperature and precipitation change in a boreal-deciduous forest ecotone (ecological boundary) located in Lake Superior Provincial Park (LSPP), Canada. An experiment site has been established at LSPP as of May 2008. To allow for precipitation and temperature manipulation, 15 rain-exclusion structures outfitted with infrared heaters were constructed over 15 experimental plots. Soil samples were collected twice per year for two years to monitor microbial response to simulated climate change. All soil samples will be analyzed for soil biodiversity via three methods: 1) Biolog EcoPlate analysis, which will examine the diversity of cultivable microbial community and its metabolic profiles; 2) denaturing gradient gel electrophoresis (DGGE), which will determine total community composition based on PCR products; and 3) phospholipid fatty acid analysis (PLFA), which will evaluate viable biomass. Together, these three tests will broadly describe the measurable microbial community. This study seeks to provide data detailing how climate change may affect the stability of soil microbial communities, which in turn may influence the stability of the forest ecosystem as a whole.