Email: jpoulin@uci.edu

An important question in ecology is what makes an invasive species successful. Does a species have an invasive potential, that is an innate ability to invade an environment? Or do successful invasions occur when an individual is simply "in the right place at the right time"? These are important questions for scientists trying to understand colonization and rapid evolution, for restoration ecologists trying to preserve and restore natural habitats, and for policy makers trying to decide how to write legislation about invasive species. Yet, they are difficult questions to address because we know very little about invasions that do not succeed. It is difficult to draw general conclusions about invading organisms based on the tiny fraction of colonization events that lead to radical changes in novel habitats. Most studies that address this issue use an invasive and non-invasive congener to look at genetic or morphological differences that facilitate invasion. However, in such an experiment, species level differences cannot be fully controlled for.

Fountain grass (Pennisetum setaceum) presents an ideal study system for addressing these difficult issues. P. setaceum is known to be one of the most noxious weeds on the Hawaiian islands, having rapidly established monoculture stands across the big island. It tolerates a broad range in elevation and temperature, as well as light and nutrient levels. Fountain grass has invaded other areas than Hawaii and is present in California, Arizona, Florida, South Africa, Fiji, and Austrailia. It is listed as one of the top eight invaders in California by CALEPPC and considered a noxious weed in Arizona. Yet, fountain grass in California and Arizona is confined to roadsides and small areas with few other plants. I am interested in what is causing these differences.

Because fountain grass is supposedly apomictic (asexual production of seeds from mitotically derived eggs with no pollination), it will be an excellent model system for looking at the importance of genetic factors in invasion success. Because these experiments will use a single species that may differ in its invasivness in variable environments, they will be ideal for studying the effects of ecological variation on invasion. I plan to do genetic comparisons of plants from Hawaii, California and Arizona, as well as fitness measures of the three ecotypes both in the greenhouse and in common garden plots.

Fountain Grass Links:

General information about Pennisetum setaceum
http://www.nps.gov/plants/alien/fact/pese1.htm
http://www.co.pima.az.us/cmo/sdcp/sdcp2/fsheets/ex/fg.html
http://www.floridata.com/ref/p/penn_set.cfm
http://www.fao.org/ag/AGP/AGPC/doc/Gbase/DATA/Pf000305.HTM

Issue papers on stopping the spread of Pennisetum setaceum
Arizona
http://aznps.org/html/exotics.html
Canary Islands
http://www.gobcan.es/medioambiente/eng/revista/1999/15/217/
Hawaii
http://www.botany.hawaii.edu/GradStud/wilkinson/fgposter2.html