Responses to water depth and clipping of twenty-three plant species in an Indian monsoonal wetland
van der Valk, Arnold
Responses of species to disturbances give insights into how species might respond to future wetland changes. In this study, species of monsoonal wetlands belonging to various functional types (graminoid and non-graminoid emergents, submersed aquatic, floating-leaved aquatic) varied in their growth responses to water depth and harvesting. We tested the effects of water depth (moist soil and flooded) and clipping (unclipped and clipped) on the biomass and longevity of twenty-three dominant plant species of monsoonal wetlands in the Keoladeo National Park, India in a controlled experiment. With respect to total biomass and survival, six species responded positively to flooding and twelve species responded negatively to clipping. Responses to flooding and clipping, however, sometimes interacted. Individualistic responses of species to water levels and clipping regimes were apparent; species within a functional group did not always respond similarly. Therefore, detailed information on the individualistic responses of species may be needed to predict the vegetation composition of post-disturbance wetlands. In particular, as demands for fresh water increase around the world, studies of life history constraints and responses to hydrological changes will aid wetland managers in developing strategies to conserve biodiversity.