1a.Objectives (from AD-416):
Human impacts on the environment are altering species composition in many of the nation's national parks. One such impact is the increase in invasive plant species which are quickly over-running many of the native plant species. One such invasive species is Japanese stiltgrass (Microstegium vimineum). The objective of the current research is to quantify human impacts, particularly nitrogen deposition, carbon dioxide and light on the ability of this species to grow and propagate.
1b.Approach (from AD-416):
Working with the National Park Service's Center for Urban Ecology, we will obtain local seed from stiltgrass populations and determine growth and see production utilizing a range of nitrogen deposition rates and carbon dioxide concentrations under glasshouse and growth chamber conditions Data will be utilized in a multiple regression model in order to ascertain whether human induced changes in macroclimate near the D.C. area will contribute to the peniciousness of this invasive species.
Meteorological and edaphic data are currently being collected and analyzed along a roadside transect in Catoctin National Park. In addition, a second study was initiated with the National Park Service (NPS) to establish exclusion fencing around existing Microstegium vimineum (Japanese Stiltgrass), (an invasive weed of national parks in the Eastern United States) stands at the Catoctin transect. The goal of the exclusion study was to determine whether, in the absence of herbivory, native plant species could out-compete the invasive microstegium. This exclusion study was established in October of 2011 and will be monitored until 2015. In addition to the in situ study, greenhouse studies examining the response of mid-Atlantic populations of Microstegium have been completed. These data have been analyzed and a manuscript, "Evidence for recent adaptative evolution in mid-Atlantic populations of an invasive exotic grass, Microstegium vimineum, Japanese stiltgrass," has been submitted to the journal, Biological Invasions.