Wieder Boreal and subarctic peatlands cover an estimated 346 million ha of the earth's land surface. They presently function as a net sink for atmospheric CO2 and as a substantial source of atmospheric CH4, an important greenhouse gas. Given predictions that climatic warming will be most pronounced in northern latitudes, the main goal of this research has been and will continue to be to gain insights into carbon balance in peatlands and gaseous exchanges of carbon between peatlands and the atmosphere. Field and laboratory studies will be undertaken to assess the historical development and the present function of peatlands. Numerous, relatively small, Sphagnum-dominated peatlands can be found along the axis to the Appalachian Mountains as far south as southern West Virginia. The Appalachian peatlands are of Quaternary age, with most having initiated peat accumulation 9,000-13,000 years ago. Within the Appalachian region, with decreasing latitude peat deposits become fewer in number, smaller in areal extent, thinner, and more highly decomposed. The Appalachian peat deposits have developed over thousands of years under climatic conditions that have been generally warmer than conditions in boreal and subarctic regions. Therefore, our research approach has been founded on the premise that comparisons between northern (cooler climate) and southern (warmer climate) peatland sites will provide insights into potential changes in boreal peatlands under predicted scenarios of global climate change. Specific objectives of this research are: to determine during long-term peat accumulation through chemical analysis of 210 Pb-dated peat cores collected from sites along a north to south gradient, to estimate turnover of photosynthetically fixed 14C in northern and southern sites to evaluate the effects of organic matter quality versus local climatic conditions on organic matter mineralization, to contrast spatial and temporal patterns in organic matter mineralization in peat in northern and southern sites, to determine the magnitude of within-site spatial variability in age/depth relationships, and to evaluate root exudation and root turnover as potential sources of labile organic matter fueling CO2 and CH4 production using laboratory mesocosm studies. Results obtained from these studies will provide insights into the carbon balance, peat accumulation/degradation, and exchange of greenhouse gases with the atmosphere under predicted scenarios of global climate change.