Brad Kennedy
Friday, October 17, 2008 - 4:30-5:00
Biological invasions represent one of the most serious threats to biodiversity worldwide. The invasive plant Red Bartsia (Odontites verna), already infesting large tracts of agricultural land in the Interlake region of Manitoba, has recently spread to nearby wildlife management areas and associated tallgrass prairie. The latter is one of North America’s most endangered ecosystems, and now covers less than 1% of its original range. Although local farmers control Red Bartsia with mulch in agricultural fields, little is known about the impacts of Red Bartsia on these prairie remnants, much less how to control it. In 2007, five recently invaded, tall grass prairie remnants were examined. Using a stratified random sampling technique, the percentage cover of all species occurring in 32 1m x 1m quadrats were recorded at each study site. Quadrats were divided evenly among the following categories: high, medium, low and zero Red Bartsia cover. Preliminary results show that in areas of high Red Bartsia cover, there is an inverse relationship between the cover of exotic species and native species In one study area, a five-replicated experiment was established to assess the efficacy of mulch on extant prairie. Treatments included mulch (low, high), sterilized topsoil (low, high), and compost tea (low, high), and a control. Soil and vegetation were sampled in 2007 prior to the application of treatments and further sampling will be conducted in the spring, summer and fall of 2008. Our results will be of great interest to managers of tall grass prairie restorations and conservation areas throughout North America, who will benefit greatly from a cost-effective and environmentally benign control for this potentially devastating invasive plant species.
Keywords: INVASIVE SPECIES, RED BARTSIA, ODONTITES VERNA, IMPACTS, CONTROL, TALL GRASS PRAIRIE, ENDANGERED ECOSYSTEM, BIODIVERSITY