The first chapter Dina Liebowitz's dissertation work is now available online in Freshwater Biology. This paper examines the relationships among environmental conditions (especially dissolved oxygen concentrations), the abundance of grazing snails, and the presence of benthic algae in Florida springs. By comparing data from field surveys both within and across springs, Dina showed that the abundance of snails (especially the genus Elimia) is the primary determinant of the abundance of algae in Florida springs. In addition, we found that algal abundance is generally either very high or very low, a pattern that is consistent with alternative stable states. Finally, our field survey also shows that oxygen concentrations, among other environmental controls, influences the abundance of snails. Putting these findings together, we suggest that even temporary declines in oxygen concentrations, which occur commonly in springs, could suppress snail populations and activity and allow algae to escape grazer control.
Most of the management attention in springs has emphasized nutrient concentrations as the major driver of algal mats, a hypothesis which we have challenged pretty strongly in an earlier paper that first articulated the oxygen-grazer-algae cascade. Dina's other chapters examine these processes experimentally, and lead to similar conclusions. Very exciting to have this work out, and congratulations Dina!
Most of the management attention in springs has emphasized nutrient concentrations as the major driver of algal mats, a hypothesis which we have challenged pretty strongly in an earlier paper that first articulated the oxygen-grazer-algae cascade. Dina's other chapters examine these processes experimentally, and lead to similar conclusions. Very exciting to have this work out, and congratulations Dina!
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