Effects of Microstegium Vimineum (Trin.) A. Camus on native woody species density and diversity in a productive mixed-hardwood forest in Tennessee

We investigated the impacts of Microstegium vimineum (Trin.) A. Camus, on the density and diversity of native woody species regeneration following canopy disturbance in a productive mixed-hardwood forest in southwest Tennessee. Field observations of M. vimineum in the forest understory pre- and post-canopy disturbance led us to believe the species might have an impact on post-disturbance regeneration. Specifically, we noticed what appeared to be a dramatic increase in post-disturbance M. vimineum which we hypothesized would compete with native woody species regeneration, negatively impacting species diversity and seedling density. Total native woody species stems per hectare declined with increasing M. vimineum cover (P<0.001, r(2)=0.80). Simple species richness of native woody species and Shannon's and Simpson's diversity indecies also decreased with increasing M. vimineum percent cover (P=0.0023, r(2)=0.47, P=0.002, r(2)=0.47 and P=0.02, r(2)=0.31, respectively). Our results indicate that M. vimineum, may have a negative impact on native woody species regeneration in southern forests. (C) 2007 Elsevier B.V. All rights reserved.