PARENT SESSION
Wednesday, August 9, 1:30-5:00 pm
COS 68 - Ecophysiology III: thermoregulation, nutrition, and photoreception
L-3, Lobby Level, Cook Convention Center
Presiders: U Rascher
Integration or segregation: comparison of responses between woody and herbaceous clonal plant species to disturbance and nutrient stress.
Hudson, Sheri *,1, Lu, Zhijun1, Franklin, Scott 1, 1 University of Memphis, Memphis, TN
ABSTRACT- Clonal plant species are able to directly translocate resources among interconnected ramets of the genet. This allows clonal plants to adopt different response strategies to heterogeneous environmental disturbances. Disturbance response may take the form of integration, segregation of damaged tissues, or severing of the rhizomatous or stoloniferous connection between the stressed or diseased tissues and the rest of the plant. In this study, we examined disturbance effects of flooding as well as nutrient stress on both a woody and an herbaceous species. The goal of these experiments was to determine the different response strategies employed by woody and herbaceous clonal plants to disturbance and nutrient stress and to analyze differences in responses between woody and herbaceous clonal species. It was predicted that herbaceous species will have a more plastic response to environmental stressors with both acropetal and basipetal translocation of resources, and little or no segregation or severing of ramets. It was further predicted that woody species would be less plastic in response to these same stressors and that there would be a higher degree of segregation or severing of damaged modules. To test these predictions, a 3 x 3 x 2 completely crossed experiment was conducted using two nutrient levels (low and added nutrient), three moisture regimes (moist well drained, flood and drought) and rhizomes that were intact or severed (between daughters or between mothers and daughters). Early in the experiment, the predictions appear to be correct.
Key words: disturbance and stress, Plant ecology, resource sharing in clonal plants