Undergraduate Research
At Its Best!

 

Student: Jennafer Hamlin
Faculty Mentor: Dr. Jennifer Rhode, Biology Department
Research Title:  Site of Origin and Degree of Plasticity Affect Success of an Invasive Liana, Celastrus orbiculatus

Jenna was funded by SEEDS (Strategies for Ecology Education, Diversity, and Sustainability;  http://www.esa.org/seeds/ ).
She presented her research at the (Ecological Society of America) Conference in Albuquerque, New Mexico

 

Many factors affect plants’ invasibility, including features of the novel community and of the plant itself. Exotic plants with greater genetic diversity or phenotypic plasticity are likely to be more successful invaders, especially under shifting environmental conditions. Celastrus orbiculatus (oriental bittersweet) is a liana whose density has reached invasive proportions in western North Carolina. Recent studies have tested bittersweet’s physiological responses to a range of light conditions. Using similar conditions to compare variation among both light levels and genotypes, I examined site-specific plasticity in this non-native liana. I predicted that genotypes would respond differently to varying light conditions and that some populations would be more plastic than others. Shade cloth structures of varying light conditions were used to simulate light levels below mature, immature, or open tree canopies. Plants from three western North Carolina sites (50 genotypes each) were cloned 8 times to allow multiple clones to be exposed to different light conditions. Clones were grown for 8 weeks with  height, leaf number, and leaf area measured after 0, 4, and 8 weeks. At the experiments conclusion, dry mass of leaves, stems, and roots was also assessed. My results showed different degrees of plasticity and patterns of resource allocation among populations. In addition, leaf response to light treatments varied among populations. These traits could facilitate increased invasiveness by oriental bittersweet, and a better understanding of the relationship between genotype and environment could be used to control this invasive’s spread.