Does cereal crop agriculture in dry swamps damage aquatic plant communities?

The response of swamp vegetation to cropping was measured by analysis of the seed bank present (as a measure of swamp resilience) and a survey of the extant vegetation (as a measure of swamp integrity). Samples of seed bank were exposed to a germination stimulus, the plants that germinated and established were identified, and the density of emergent vegetation was assessed. Surveys of the extant vegetation after flooding in cropped and uncropped swamps indicated that the plant communities establishing after the different treatments were different. Cropping results in a reduced diversity and density of plants, although swamp plant communities retain some resilience to such disturbances. Cropping also affects germination from the seed bank of these wetlands. The degree to which cropping is a threatening process to swamp plant communities and their dependent fauna will depend on whether vulnerable elements can return to swamps, which in turn depends on swamp management, connectivity and landscape level processes. As the climate changes and wetlands become more temporary and flooding less reliable, recognition and conservation of the processes that maintain biodiversity in the landscape will become more important.

► In the current drying climate lowland temporary herbaceous wetlands (swamps) are exposed to a new land-use (cropping instead of grazing).
► Cropped swamps had reduced integrity and resilience compared to uncropped swamps.
► Cropping results in fewer species and less dense plant communities establishing from the seed bank, and in the extant vegetation.
► There is evidence that swamps can survive cropping, but with reduced integrity and resilience.