Relationship between the spatial scale and biotic variability in a wetland ecotone

We studied potential effects of the expansion of a wetland ecotone on phytoplankton communities. The expansion of ecotone width and emergence of a mosaic of habitats are expected outcomes of a reduction of carp numbers and a consequent managed vegetation recovery. Specifically, we investigated the effects of decreasing size of open water cells on species richness, abundance and diversity. In a set of experimental enclosures of four different sizes we sampled phytoplankton weekly during 1991. The phytoplankton communities showed similar patterns of seasonal change but no clear differences in species abundance or richness that could be attributed to the system size. Notably, however, the magnitude of variation in the community structure metrics responded strongly to the enclosure size. This indicates that the importance of scale may not be fully appreciated when analyzed in the light of standard community measures. We tentatively conclude that the variation in species composition, individual responses, richness, and abundance may result in an increasing diversification of the wetland ecotone as the recovery of vegetation advances.