Plant invasion in a changing world

The invasion of nonnative plant species often has severe environmental and economic impacts, and such invasions are a leading cause of habitat loss worldwide. In California, the invasion of nonnative annuals from the Mediterranean has led to the widespread loss of native ecosystems and alterations to ecosystem processes and services. As my research has shown, other drivers of environmental change, such as nitrogen (N) deposition and extreme drought, may increase invasion success. But how will invasive species respond evolutionarily to these factors? My current research, supported by UC Los Angeles and the U.S. Department of Agriculture, is exploring the eco-evolutionary consequences of N deposition and climate on common invasive species of California. This work has important implications for the management of nonnative plant invasion under predicted environmental change.

Some of my ongoing experiments are comparing the plant functional traits of populations of invasive species throughout southern California, including sites receiving relatively high and low levels of nitrogen deposition. Preliminary results suggest that populations of some species (such as the grass pictured here) exhibit more rapid growth, but it remains to be determined the extent to which this is due to environmental maternal effects or adaptive evolution.