Ecological interactions among native and non-native species

My lab has several projects examining the interactions of native and non-native plants and insects in riparian and coastal wetland systems in the southwestern United States, and how non-native plant and insect invasions alter these ecosystems. Study plants include giant reed (Arundo donax), common reed (Phragmites australis), perennial pepperweed (Lepidium latifolium ), and Tamarisk (Tamarix spp.), and the insect herbivores and native plants that interact with these species. We are assessing the effects of native and introduced herbivores on plant growth, survival, and competition.

Riparian and wetland restoration

The research aspects of my work are applied directly to reducing the impacts of invasive species on riparian systems, as well as restoring the ecological and habitat value of these systems that have been lost through human caused degradation. In the Santa Clara River (Ventura and Los Angeles Counties, CA), we are working with non-profit and government agencies to plan for and restore over 800 acres of floodplain habitat.

Tri-trophic interactions
I also study both pairwise and tri-trophic interactions between plants and insects. One of my projects examines the multilevel relationship between secondary chemicals and defensive structures in plants important for agriculture and declining insect species, the herbivores that feed on them, and their insect predators.  A key aspect is elucidating the differential effects of plant defenses on generalist versus specialist insect predators, and whether host-specific adaptations to plant defenses 'protect' specialist predators from the negative effects that generalists experience. I am also interested in how allelochemicals differ among plant genotypes and how these differences affect plant quality, competitive interactions among closely related plants, and herbivory.

Population dynamics and distributions
In a collaboration with Kristin Saltonstall (Smithsonian Tropical Research Institute), I am evaluating the genetic structure and distribution of Phragmites biotypes in the southwest US using molecular techniques. This information is part of a larger effort to develop a GIS database and detailed distribution maps for native and non-native biotypes in the region to facilitate conservation efforts for native biotypes and control efforts for the non-native biotype.

If you are interested in working on any of these projects, please contact me at alambert@ucsb.edu