Ecosystem process and function of temporary wetlands: baseline data for climate change predictions.
Abstract
This study project aims to: (1) determine rates of biogeochemical cycling generated by primary producers (micro- and macroflora) in temporary wetlands during different levels of inundation in order to better refine this process for use in global climate change models. (2) To examine lower trophic level relationships in temporary wetlands under different levels of inundation and link these to different climate change models. (3) To experimentally determine different temperature, water level and nutrient regimes that effect the growth and production of various algal taxa, for use and refinement in existing climate change and eutrophication models. (4) To model changes in ecosystem services derived from ephemeral wetlands in peri-urban and urban environments associated with changes in global climate. (5) To generate baseline information on selected urban wetland(s) in support of ICLEI-LAB (International Council for Local Environmental Initiatives - Local Action for Biodiversity) and Nelson Mandela Bay Metropolitan environmental services division to enable better management decisions to be made for rehabilitation, restoration and maintenance of wetlands in the face of climate change. In order to address the research aims above a range of desktop, field and laboratory methods was used. The results of the preliminary experiments using a range of sediments from different common hydrogeomorphological (HGM) units and average minimum (17°C) and moderate (24°C) summer temperatures to show that (1) successful hatching from the sediment egg bank was possible and (2) temperature had an effect on the numbers of hatchlings and species. These also demonstrated that sediments from depression and wetland flat HGM units were well suited to these experiments and had evolved an egg and seed bank whereas seeps did not have this same mechanism for repopulation after inundation/re-wetting and developed a different type of invertebrate community.