POTENTIAL EFFECTS OF CLIMATE-CHANGE ON A SEMI-PERMANENT PRAIRIE WETLAND

We assessed the potential effects of a greenhouse gas-induced global c limate change on the hydrology and vegetation of a semi-permanent prai rie wetland using a spatially-defined, rule-based simulation model. An 11-yr simulation was run using current versus enhanced greenhouse gas climates. Projections of climatic change were from the Goddard Instit ute for Space Studies (GISS) general circulation model. Simulations we re also run using a range of temperature (+2 and +4-degrees-C) and pre cipitation change values (-20, -10, 0, +10, +20%) to determine the res ponsiveness of wetland vegetation and hydrology to a variety of climat e scenarios. Maximum water depths were significantly less under the en hanced greenhouse gas scenario than under the current climate. The wet land dried in most years with increased temperature and changes in pre cipitation. Simulations also revealed a significant change in the vege tation, from a nearly balanced emergent cover to open water ratio to a completely closed basin with no open water areas. Simulations over a range of climate change scenarios showed that precipitation changes (p articularly increases) had a greater impact on water levels and cover ratios when the temperature increase was moderate (+2-degrees-C). Thes e potential changes in wetland hydrology and vegetation could result i n a dramatic decline in the quality of habitat for breeding birds, par ticularly water-fowl. Continued research on climate and wetland modeli ng is needed.