Region 1. - Laurentian Great Lakes and Precambrian Shield
The purpose of this brief report is to present a preliminary overview of the findings from the symposium Regional Assessment of Freshwater Ecosystems and Climate Change in North America for the participants in the symposium, the membership of the two participating societies, ASLO and NABS, and for the sponsoring agencies the Environmental Protection Agency and the U.S. Geological Survey. The eight regions identified for this assessment are presented on the cover of this report. In addition to geographic and hydrologic considerations, regional boundaries were set with the goal of compatibility of scale with meso-scale Global Circulation Models (GCM’s). The region typically encompasses several ecoclimate regions and specific areas within a region are considered for in-depth analysis. The following summaries begin with a description of significant or unique geographic and climatological characteristics of each region and of major types of aquatic ecosystems found within each region. Most of the summaries briefly review the long term climatic patterns based on paleo records, and near term trends indicated by instrumental records. The regional groups were tasked with considering responses to a doubling of atmospheric carbon dioxide (referred to here as 2X C02 scenarios). Uncertainties in predictions from GCM’s presented a major challenge for every regional working group, and in the summaries each group discusses their approach to this challenge. The possible consequences for aquatic ecosystems which may result from the 2X C02 scenarios were identified from the literature and ongoing studies and are highlighted in the summaries. Also addressed are interactions between anthropogenic impacts on aquatic ecosystems and possible climatic effects. The caveat that the projected responses and interactions are speculative in nature applies to all the regions. The summaries conclude with preliminary recommendations for data collection and research. These recommendations will be further developed in the final regional working group reports that will be published in the journal Hydrologic Processes.