GK12
Brandy Janzen NSF Graduate Fellow
Thesis Title:
ANNUAL AND SEASONAL FLUCTUATIONS IN SPECIES COMPOSITION OF SAGEBRUSH STEPPE IN RESPONSE TO EXPERIMENTAL MANIPULATIONS OF PRECIPITATION AND SOIL PROFILES

Research Advisor:
Dr. Matt Germino

Teacher Partner:
Carol Smith and Joseph Timchak

Degree Sought:
finish MS Fall 2009, begin PhD Spring 2010

University Department and/or Lab:
Biological Sciences

Research Focus:
Plant Community Ecology

Description of Research:
Diversity of semiarid plant communities is thought to be linked to functional diversity among plants, and depth of water uptake is a key difference between functional groups; shrubs can utilize deeper soil water while herbaceous species primarily rely on shallower water sources. I examined changes to sagebrush steppe communities subjected to long-term manipulations of soil profile depth and seasonal precipitation (approximately a doubling of average annual precipitation). Experimental plots with the shallowest soils had significantly less vegetative cover (% ground area) and generally the lowest diversity. Lower cover in shallow soils was due to shrub cover which seems to be adversely affected by shallow soils. Plots receiving irrigation had the greatest cover, particularly forbs, and greater diversity. My results suggest that deeper soils tend to promote the greatest diversity in semiarid regions and irrigation promotes greater vegetation cover, thus a greater potential to remove soil water.

One example of how you integrate your research into your GK-12 experience:
I am hoping to work in some energy balance, with respect to plants, related lab experiments into the physics section of the year. During the chemistry section I am hoping to be able to draw on my soil chemistry background to come up with some interesting labs.


Profile date: September 2009

fellow

Brandy Janzen
janzbran@isu.edu