Plant conservation research has mostly focused on easily identified threats: habitat conversion, loss, or fragmentation, and competition from invasive exotics.  But some species decline even when their habitat seems intact. One example of such a decline is that of the perennial legume, Desmodium cuspidatum (large-bracted tick-trefoil, Fabaceae), which has declined recently in New England (from 28 to six populations since 1976).  Though this species’ range extends across the eastern half of the United States, New England populations, determining the northeastern boundary, are the only populations known to have declined in recent years.  Desmodium cuspidatum is now listed as endangered in Vermont, endangered in Massachusetts, watch-listed in Connecticut, and historic in New Hampshire and Rhode Island. I am investigating aspects of this species’ biology to determine how less apparent but ecologically and evolutionarily significant factors, may contribute to population declines. 

My research has two main goals. The first focuses on characterizing genetic diversity, reproductive biology and demography, “classical” factors that may contribute to or be the consequence of declining population numbers.  The second investigates the role of anthropogenic increases in nitrogen deposition on declines in this nitrogen-fixing plant species.