Estimating the effects of global climate change on streamflow and wetlands in the watershed of the Pere Marquette River, Michigan

A major theme in the field of ecology is the relationship of vegetation to the physical environment. Important factors in the physical environment of wetlands are the amount and timing of delivery of water. This study examines the potential effects of climate change on wetlands in the watershed of the Pere Marquette river.; Stream discharge in the Pere Marquette river increased 56% over the last 50 years. Precipitation increased by 4.67 cm, and minimum and maximum temperature decreased by approximately 0.55°C and 0.89°C over the last 40 years.; A stream discharge model was constructed for the Pere Marquette river, and three global climate models (General Fluid Dynamics Lab: GFDL, Canadian Climate Centre: CCC, and Ohio State University; OSU) were used to estimate stream discharge under doubled carbon dioxide conditions. Historical temperature and precipitation trends were used to project stream discharge in 2050. Two GCM's (CCC and OSU) predicted discharge similar to historical discharge. The third (GFDL) predicted stream discharge similar to historical trends projected to 2050.; Change in riparian vegetation cover type was estimated for a site along the mainstem of the river. Vegetation was sampled at 25 plots in the field. Detrended Correspondence Analysis and Two Way Indicator species Analysis were used to group the sample plots into four vegetation types: Acer-Tsuga, Fraxinus-Carpinus, Alnus, and Viburnum. Vegetation change was estimated by using inundation as the major factor structuring riparian vegetation. The fraction of time that each plot was likely to be inundated was computed for each plot for baseline, 2050, and GCM stream discharge.; The results suggest that at least 20% of the sampling plots may change from one vegetation class to another under the 2050 and GFDL strewn discharge regimes. The OSU and CCC climate models predicted inundation conditions similar to historical stream discharge conditions.; Change in regional wetlands was estimated using geographic information systems software and methods similar to those used to estimate change in riparian vegetation. The results suggest that under the wettest scenarios (GFDL and 2050) there would be a shift of 8% of the watershed area towards wetter vegetation types.