Students

I am an active member of the Environmental Science & Policy Graduate Program at the University of Wisconsin - Green Bay. We offer M.S. degrees with emphases in Ecosystem Studies, Resource Management, and Environmental Policy & Administration. If you are interested in pursuing a M.S. degree under my direction, please contact me directly.

Joshua A. Martinez:

Status: Current M.S. student

Thesis: The potential use of inter-specific facilitation to restore native woodland herbaceous communities in urban preserves facing strong biotic resistance.

Thesis Summary: Josh is examining the potential use of a native woodland grass (Elymus virginicus) to facilitate the establishment of palatable native woodland species. This experiment is established within a Northeastern Wisconsin urban preserve that carries high whitetail deer (Odocoileus virginianus) densities and extensive invasion by the exotic biennial herb, garlic mustard (Alliaria petiolata). Josh is quantifying local whitetail activity using fecal group counts. Facilitation experiments are established in 6 replicated blocks, with E. virginicus planted at three different densities. Deer exclosures prevent browsing in half of all treatments plots within each block, with seedlings from the palatable-forb target species planted at a constant density within each facilitation plot. Josh is also examining the differential effects of Elymus virginicus density on the survivorship of a suite of seeded native species and the natural establishment of non-seeded species and garlic mustard.

Philip G. Hahn:

Status: Current M.S. student forest

Thesis: Does Apparent Competition Promote Dominance of Alliaria petiolata (Garlic Mustard)?

Thesis Summary: Phil’s research expands upon an existing experiment examining the effects of Alliaria petiolata (garlic mustard) invasion, deer browsing, and native plant restoration on woodland plant diversity in northeastern Wisconsin. Preliminary results suggest that native seedling establishment is limited by A. petiolata presence, and that grazing by exotic slugs may significantly enhance the mortality of native seedlings. Exotic slug populations appear facilitated by the moist soil conditions created by dense cover of A. petiolata. As a result, native recruitment in dense A. petiolata stands may be limited by both A. petiolata competition and slug herbivory, not solely via direct competitive exclusion by A. petiolata as previously hypothesized. Phil’s research investigates direct competition between A. petiolata and native plants, as well as slug mediated apparent competition between A. petiolata and native plants.

Simone E. Kolb:

Status: M.S. December 2007

Thesis: Understanding the mechanisms by which a manure-based charcoal product interacts with soil to affect microbial biomass and activity.

Thesis Summary: Phosphorous loading of freshwater systems is a serious, long-lasting, and unintentional environmental impact than can result from livestock production. At the same time, the offsite transport of manure needed to reduce potential environmental impacts is often hindered by the high cost of transporting the largely liquid waste. Recent advances in pyrolysis technology may provide the dual benefit of converting livestock manure into a local, renewable energy source, and an easily transportable and agriculturally beneficial soil amendment in the form of charcoal. To examine the potential effects of charcoal additions to temperate soils, Simone’s thesis examines the effect of varying charcoal application quantity on soil microbial biomass and activity among four distinct soil series from Wisconsin, USA.

Publications: Kolb, S.E., K.J. Fermanich, M.E. Dornbush. 2009. Effect of charcoal quantity on microbial biomass and activity in temperate soils. Soil Science Society of America Journal 73: 1173-1181.