PARENT SESSION
Monday, August 7, 5:00-6:30 pm
Poster Session 2 - Invasive species
Exhibit Hall, Ballroom Level, Cook Convention Center

N-fixation by kudzu (Pueraria montana): impacts on nitrogen cycling and soil microbial communities by an invasive vine.

Hickman, Jonathan^*,1, ¹ SUNY at Stony Brook, Stony Brook, NY

ABSTRACT- Among invasive plants, those that fix nitrogen (N) present a clear threat to the integrity of native ecosystems. Kudzu (Pueraria montana) is a legume that has become highly invasive in the U.S., and is known to fix nitrogen in its native range. Kudzu's tendency to form dense stands and its extensive coverage in the southern U.S. may increase rates of N cycling and accumulation in soils, potentially leading to changes in community composition, soil acidification, and increased fluxes of trace N gases and leached nitrate to neighboring ecosystems. We present data on the effects of kudzu invasion on nutrient cycling and microbial communities for sites in the McKee-Beshers Wildlife Management Area in Montgomery County, Maryland. Two pairs of sites were selected for sampling; each pair consisted of invaded and uninvaded sites in close proximity, with similar slopes, aspects, and land-use histories. Soil samples were collected from each site and analyzed for extractable nitrate and ammonium, net N mineralization, net nitrification, denitrification enzyme activity, and microbial biomass. Preliminary results suggest striking effects of kudzu invasion on ecosystem processes, with large increases in N-cycling parameters occurring in the invaded sites.

Key words: Nitrogen Cycling, Invasive Species, Pueraria montana