Research interests

          My primary research examines the effects of non-native, invasive species on natural habitats, the mechanisms underlying invasion success, and insect herbivore-mediated interactions between native and non-native plants. My research objectives include: 1) understanding ‘how’ and ‘why’ some invasive species (but not others) are so successful, 2) elucidating how insect herbivores alter competitive interactions between native and non-native species, 3) identifying host specific natural enemies and testing their efficacy in controlling invasive species, and 4) examining conservation and restoration strategies before, during, and after invasive species control or removal.

Ecological interactions among native and non-native species
          Currently, I am studying the interactions of native and non-native plants in riparian systems in the southwestern United States and documenting how non-native plant invasions in riparian areas of this semi-arid region are altering ecosystems. My current projects include establishing baseline measures of the environmental effects and changes in biodiversity caused by establishment of non-native Arundo donax and Tamarix spp., evaluating the current herbivore complex associated with Arundo in the United States, and studying herbivore effects on Arundo growth and survival. I am also continuing research I conducted during my doctoral work on competitive interactions of native and non-native biotypes of Phragmites australis. The non-native biotype is rapidly invading and changing wetland ecosystems in the United States and replacing native biotypes. I am studying the factors that enable the exotic biotype to out-compete the native biotype and other native plants, and how biodiversity changes and declines over time as the non-native species invades. I am also looking at the differential susceptibility of the native and non-native biotypes to native and non-native herbivores.

Population dynamics and distributions
          I am researching genetic structuring among the different Phragmites biotypes using molecular techniques (RFLP’s and ISSR’s). With this information, I am constructing a GIS database to map the distribution of native and non-native biotypes in New England and California. This database, which incorporates georeferenced data and population parameters (distribution and abundance, genotype, habitat), will enhance conservation efforts for native biotypes and control efforts for the non-native biotype. This database will also be used to study the spread of invasive species and their effects on biodiversity. Another aim of this research is to develop accurate and ‘easy to use’ genetic techniques for identifying closely related native and non-native plants.