Spatial-temporal trends in exotic species distribution in the Gwynn Fall's Watershed
 
Molly Sandomire

 
In 1999, and again in 2004, researchers from Johns Hopkins University collected data on plant frequency and distribution at forty-six locations each year throughout the Gwynn Falls watershed. This data has been imported into a database for analysis using GIS to investigate spatial and temporal changes in plant frequency and distribution.
 
This study has two parts. The first part of the study looks at overall changes in the frequency and distribution of exotics in the watershed. How have spatial patterns of exotic species with the GFW changed between 1999 and 2004, and how do these patterns compare with overall changes in diversity?
 
The second part of the study traces the progress made by several of the more notorious exotic weed species and compares their distribution with those of some prevalent native groundcovers. The specific species investigated include Lonicera japonica (Japanese honeysuckle), Polygonum cuspidatum (Japanese knotweed), Glechoma hederacea (ground ivy), Hedera helix (English ivy), Rosa multiflora, Microstegium vimineum (Japanese stiltgrass), Symplocarpus foetidus (skunk cabbage), and Phalaris arundinacea (reed canary grass). Cluster analysis will be used to separate individual species into those with expanding, maintaining, or contracting ranges.
 

 
Keywords: Exotic plants, spatial-temporal analysis