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Harvard Forest REU Symposium Abstract 2005
- Title: Investigating the Physiological Effects of Invasive Plants in the Presence of Black Locust (Robinia pseudoacacia)
- Author: Antoinnine R Cooper (Oakwood University)
- Abstract:
Since its introduction to New England in the late 18th century Robinia pseudoacacia (black locust), a nitrogen fixing tree species native to the Ozark and central Appalachian Mountains, has become one of the top 100 invasive woody plants in the world. Previous studies have found nonnative species to be ten times more abundant in Robinia stands than in native overstory stands which consist of pitch pine (Pinus rigida) and mixed pitch pine-oak (Quercus velutina and Quercus alba) communities. The native plots were located only 20m away from Robinia and yet showed significant difference in understory density of nonnative plants. As a result of hurricane Bob, which ripped through New England in 1991, black locust stands decreased in size. However, the nonnatives in the soils where these trees once stood continued to thrive at a much higher abundance than that of the native stands. To find the difference in nonnative germination in Native, Legacy, and Robinia soil types, we compared physiological responses to light as well as the biomass of six nonnative species. Both the rate of photosynthesis measured at ambient CO2 and the biomass of the nonnatives were significantly higher in Robinia and Legacy soil types than native soils. Nonnatives had greater water use efficiency and stomatal conductance in legacy and Robinia soils. This data suggests that the increased nitrogen in Robinia soils may contribute to the success of nonnative plants.
- Research Category:
