Thursday, August 5, 2010

PS 66-10: Increased arthropod abundance and diversity in Microstegium vimineum invasions

Judith L. Metcalf, University of Louisville

Background/Question/Methods

The potential for invasive species to alter regional biota and cause native species decline is a cause for much concern.  Microstegium vimineum is an invasive annual C4 grass that thrives in disturbed environments and is dominant in many eastern deciduous forests.  Because this grass plays an important role in determining the community structure in the understory of these forests, it also has the potential to significantly alter arthropod community structure.  Here we present data from a pilot study evaluating the impact of Microstegium vimineum on arthropod abundance in a disturbed forest in Northern Kentucky.  Arthropods were collected using sweep nets at 6 paired sites (invaded/uninvaded) in the Horner Wildlife Research Forest in Brownsboro Kentucky in 2008.  Arthropods were identified to morpho-species and counted.  These data were then analyzed using a paired t-test. 

Results/Conclusions

While there were no significant differences in spider abundance between invaded and uninvaded sites, both insect morpho-species richness and abundance were significantly higher in invaded sites.  Future plans for this study include additional arthropod abundance and biomass studies as well as manipulative studies to evaluate the effects of M. vimineum on arthropod food webs.