Department of Biology’s Kristina Schierenbeck, right, and her
graduate students, Sherry Ellberg, middle, and Darhl Bradford,
left, are examining the first blooms on the rare species,
C Larkia lingulata. These two to three month-old specimens are
part of a crossing experiment looking into the evolutionary
origins of the plant. (photo DA)
Schierenbeck's research on invasive non-native plant species was the subject of her doctoral dissertation at Washington State University. These species that compete with native crops are a problem that, according to Schierenbeck, cost the U.S. economy $220 billion annually. A well known Chico example, Ailanthus altissima, commonly known as the tree of heaven, has been invading the natural habitat of Big Chico Creek.
Schierenbeck has focused on the inherent problems in the hybridization of native and non-native species.
According to Schierenbeck, "When hybridization and a backcrossing of the hybrid into the native species occurs, we end up with the genetics of the original native species being literally swamped out, and the original genes are lost."
Another thing that can happen, said Schierenbeck, is that non-native species can capture advantageous genes from native species, and those can enable them to spread into an even wider range of habitats and become even more competitive and devastating to native eco-systems.
Currently, Schierenbeck is working with graduate students to measure the direction of gene flow between native and non-native species, looking specifically at the ice plant hybrid. The ice plant, carpobrotus edulis, was planted widely by the California Conservation Corps in the 1930s along roadways and railways to control erosion. Ironically, if the hillside is too steep, the plant can actually increase erosion because of increased weight on the soil. The State of California is now actively removing the ice plant at great expense.
Today, ice plant runs all along the highways in southern California and covers everything completely. Schierenbeck explains how ice plant is a prime example of "how incredibly effective hybrids are at not allowing anything else to grow. This is what we call hybrid vigor."
Schierenbeck is also working at the other end of the spectrum of genetics. "When you're looking at plant species in general, one end is really wide-spread and invasive, the other end is extremely rare and limited. What they have in common is that they both have applications in conservation. I am specifically looking at theoretical problems in population genetics and systematics biology and applying them to conservation. By understanding the causes of gene flow in either invasive or rare species, we can then determine how to use these causes in their management, often through limiting their spread," she explained.
Schierenbeck's research earned her a Research and Faculty Development Award. She is grateful for this grant, explaining "It's helping me gather preliminary date to secure larger funding from the National Science Foundation."
Beyond her research and teaching, Schierenbeck is also the director of the Chico State Herbarium. "Chico State has one of the best herbaria in California, and the United States. There are over 70,000 species; it's a very good representation of the northeastern California flora," said Schierenbeck. Currently she is trying to secure funding for a full-time curator.
All of this points to a fruitful career for Schierenbeck, who is grateful for the strong support she has received since returning. She said, "The department and the school have been exceptionally wonderful and supportive in helping me get established here with both my research and teaching. I'm really happy to be back at Chico State."