Community Diversity as a Determinant of Invasion Success (Sierra Nevada, CA).

In my research in grassland communities of Northern California I investigated the relationship between diversity and non-indigenous species establishment.  The results of this work supports the hypothesis that species diversity is negatively correlated with invasive species establishment and that even rare species may be important in maintaining resistance of plant communities to invasive species.  My work on this subject has also demonstrated that increasing diversity can also reduce the effectiveness of community species that suppress the non-indigenous species at lower levels of diversity.  This suggests that, when species abundances of all species decline at the high end of diversity, effectively reducing individual species impact on new species establishment, niche partitioning and species complementarity are more likely to operate to suppress the new species.