Faculty Advisor

Kirkpatrick, Betsy

Area of Study

Science and Mathematics

Publication Date

Summer 2011


Scotch broom is a non-native plant that has invaded plant communities worldwide. Able to grow on a variety of soil conditions, Scotch broom associates with soil bacteria to fix nitrogen (N) from the atmosphere, elevating soil N and crowding out native plant species by encouraging the growth of non-natives like itself. Adding carbon (C) has been used in previous studies to lower soil N and restore native plant growth. However, little is known about C-amendment’s effects on the soil microbial community that correspond to changes in soil N and plant community composition. Recent studies have shown that C-amendment increases microbial populations in soil. Researchers propose that C-amendment affects certain species of soil bacteria at different times after treatment. Given this model of C-amendment’s effects, we hypothesize that there should be a detectable change in the dominance of certain species within the total soil microbial community. Soil samples were collected from sugar-treated and untreated plots at Glacial Heritage Preserve, a Puget lowland prairie site in Olympia, WA. Our study investigates how C-amendment affects the functionality of the soil microbial community in a Puget lowland prairie invaded by Scotch broom using BIOLOG ecoplates.


University of Puget Sound

wong_summer_2011_poster.ppt (755 kB)
Poster in MS Powerpoint format