부산대학교 도서관

We analyzed the effect of damming on the temporal patterns of the composition and richness of phytoplankton Reynolds functional groups (RFG) from a subtropical floodplain, together with its drivers. We obtained data of environmental factors and presence–absence of RFG from sites at both a dammed and a non-dammed region, sampled at least twice a year for 19 years. Since damming decreases the effect of flooding in floodplains, as it isolates adjacent environments, changes environmental conditions, and decreases its temporal variation, we tested if, over time, damming could (i) decrease the richness, (ii) shift the functional structure, (iii) increase the spatial turnover, and (iv) decrease the within-year turnover. Only the dammed region showed changes over time, with a decrease in the richness and the shift to a new functional state, represented by flagellates. The low influence of flooding seemed to be the main driver of these changes by allowing the increase in nutrients (with negative effect on richness) and limiting the arrival of organisms from distant sites. By shifting the functional structure and causing the loss of RFGs, damming could trigger changes in the ecological interactions of floodplains and negatively affect the energy flux from the phytoplankton to superior trophic levels. [ABSTRACT FROM AUTHOR]