Effects of damage and pollination on sexual and asexual reproduction in a flowering clonal plant

The extent to which local biotic factors like herbivory and pollination affect mode of reproduction in plants is not yet fully understood. Mode of reproduction is ecologically important because it can influence the spread and distribution of plant populations through factors like offspring dispersal distance and establishment success. The two experiments described here address the potential effects of damage and pollen receipt on plant growth, sexual reproduction, and asexual reproduction in a clonal flowering plant (Eichhornia crassipes, water hyacinth). These experiments were conducted in greenhouse and outdoor tanks at the Florida State University research facilities in Tallahassee, FL, on plants collected from north Florida populations. Plants received manual damage to leaves (imposing a loss of resources), apical meristems (imposing a loss of leaf and flower production), or axillary meristems (imposing a loss of clone production). Apical meristem damage increased asexual reproduction (clone number). When severe, axillary meristem damage increased plant growth (leaf production). Neither leaf damage nor pollination affected plant growth, clone production, or flower production. Asexual reproductive responses to damage have not been well studied, although sexual reproduction and individual plant growth have been shown to increase following damage. These results have implications for the dispersal and establishment of clonal plants in the presence of herbivory. For a highly invasive species like E. crassipes, these results can further inform the use of insect herbivores to manage invasive populations.