AgBioResearcher Seeks Predictability in Equation

September 25, 2009

Jennifer Lau, based at the Kellogg Biological Station, won a four-year, $630,000 grant from the National Science Foundation to explore how genetic variation in native and non-native plant species affects biological invasions.

With exotic invaders such as garlic mustard plants threatening Michigan forest ecosystems and purple loosestrife crowding out native cattails in wetlands, improving the ability to predict and prevent damaging plant invasions is the aim of a research initiative spearheaded by an MAES plant evolutionary ecologist.

The research will focus on two common annual plants in the California coast range. The non-native burclover, Medicago polymorpha, is a shallow-rooted legume that can become invasive. The other is a closely related non-invasive native, Lotus wranglianus, also known as Chilean bird's-foot trefoil. Both plants are important in agriculture and natural ecosystems as forage and cover crops.

Lau contends that applying community genetics to invasion biology provides a broader understanding about what?s happening when different genotypes interact with a common environment.

"There is a tremendous amount of variation between individuals of a single species in traits that influence survival in different environments," Lau said. "For example, plants introduced to Michigan from warmer regions may have limited cold tolerance and, as a result, may not become invasive. However, a plant of the same species that came from the northern area of the species? range is likely adapted to cooler temperatures. That plant may be able to survive cold winters and successfully invade. Similarly, genotypes of native plants may vary in their ability to resist invasion and/or coexist with invaders."

A common plant invader in Michigan is garlic mustard, an invasive species that threatens the state?s woodlands. Many land managers consider it to be one of the most potentially harmful and difficult to control invasive plants in the region.

"We're still trying to figure out what garlic mustard does, but it basically takes over an entire forest understory, compromising biodiversity and forest health," Lau said. "It somehow becomes a monoculture, crowding out forest understory natives such as jack-in-the-pulpit, trillium and trout lilies. I'm hopeful this research will shed more light on situations like this. My bet is that a successful invasion depends on the match between the genotype that happens to make it to the area and the other organisms that are already in that community and the climate and soil conditions of the habitat."

A better understanding of the invasion process may help prevent future adverse invasions and also may aid in ensuring the success of intentional introductions for production agriculture or biological control.

"This topic is both timely and important," said MAES director Steve Pueppke. "Such linkages between genetic variation and ecological processes were relatively unknown even five years ago. The results of this study will have important implications for both basic and applied ecology."

The research also will provide opportunities for training high school students in large-scale ecological field research at KBS. Lau and a graduate student will partner with teachers in the National Science Foundation-funded K-12 program at KBS to create curricula focused on biological invasions. Those will include a general introduction to biological invasions and community ecology, suggested field experiments on the community consequences of invasions and a brief statistical tutorial.