EFFECTS OF SIMULATED CLIMATE CHANGE ON SOIL MICROBIAL DIVERSITY AND PLANT-MICROBE INTERACTIONS IN LAKE SUPERIOR PROVINCIAL PARK, CANADA

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 have been constructed over 15 experimental plots. Soil samples were collected twice in 2008 to yield a pre-treatment sample (May 24, 2008) and a first-season sample (August 16, 2008). 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 based on viable biomass concentrations, community composition, and cultivable metabolic activity. Measuring the effects of fluctuations in soil moisture and increases in soil temperature on microbial diversity will potentially provide significant data on how global warming might affect not only the stability of the soils, but also the stability of the forest macro-ecosystem.