Grant: Strategic Projects - Group

Continued climate change will ultimatelyreveal how forest SOC will respond to increasing temperatures. However, predicting these changes is critical to the development of societal strategies for coping with climate change, given the significance of soil organic matter to forest ecosystem function, sustainability, and global C cycling. Current trends in stream dissolved organic carbon (DOC) and our increased understanding of DOC-SOC linkages at the landscape level suggest that DOC can reflect important, integrated signatures for predicting change in SOC pools. The work described in this proposal will determine to what extent increased microbial transformations of SOC and losses of relativelyrecalcitrant pools of SOC mayoccur with warming along a boreal forest transect. To isolate the potential impact of warming while maintaining our abilityto apply the results to intact boreal forests, we will conduct investigations of soils and the DOC theyproduce along a latitudinal transect of boreal forest sites, as well as manipulative warming experiments on these soils to develop biogeochemical indicators of soil responses to increasing temperature. Our work combines geochemical, isotopic, and biological approaches to discern changing SOC and DOC composition with warming, and to elucidate the influence of biological mechanisms vs. soil mineralogydriving these changes. Further, our assessment of these indicators at the small watershed scale represents the first step toward developing landscape scale, integrative indices of climate-induced changes in boreal forest SOC processing andstocks. This research will benefit our supporting organizations, which include the forestryindustryand both provincial and federal forest services, byproviding novel indicators and a predictive understanding of key climate change responses in boreal forests. This can be used to inform forestrymanagement practices aimed at reducing the potential negative interactive effects of climate change and harvesting or other disturbance regimes.