CARBON SEQUESTRATION BY PEATLANDS IN EASTERN NORTH AMERICA RESPOND TO GLOBAL AND REGIONAL CLIMATE CHANGES

One of the most important ecosystem services is carbon sequestration. Since the last glacial period, northern peatlands have accumulated about a trillion tons of carbon. Of these northern peatlands, about 15% of which is found in Eastern North America alone. If we are to fully appreciate this critical resource, we must understand the impacts of changing climate on the strength of the peatland carbon sink. Towards this aim, we present a new, 25 ka record of peat carbon accumulation in peatlands throughout Eastern North America. We show that carbon accumulation rates are strongly sensitive to globally important climatic shifts, such as the Younger Dryas, and Bølling-Allerød warm period. By comparison with stable hydrogen isotope, testate amoebae, and paleovegetational reconstructions of climate from peatlands, we also show that peatlands respond strongly to regional-scale climate shifts, such as the droughts associated with the mid-Holocene Tsuga decline. We find that regional peat carbon accumulation increases strongly and quickly during warm periods. Peat carbon accumulation declines during cold or dry periods, but recovery is faster following cold periods than following dry periods. As the Eastern US is predicted to become both warmer and wetter in the future, Peatlands may act as a negative feedback on anthropogenic warming, but only if we protect these important environments from peat mining and land-use change.