IMPACTS OF CLIMATE VARIABILITY AND CHANGE ON CANADIAN WETLANDS

The occurrence of wetlands requires a supply of water exceeds evaporative losses. This water balance is strongly influenced by the climate. Short-term fluctuations of the climate can alter the wetland water balance. The drying and inundation of prairie wetlands during dry and wet climatic cycles provide an example. The effect of warmer and wetter conditions on a northern Ontario wetland was also simulated. Long-term climatic warming will alter many physical attributes of wetlands, leading to earlier snowmelt, higher evapotranspiration and lowering of the water table. The impacts will vary for wetlands in different parts of Canada. The influence of human activities on wetlands is a significant factor which may accelerate the pace of environmental change.