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Exploring the interactions between carbon cycling, land use and climate change within mixed agricultural, forested, suburban, and urban landscapes NASA, Carbon Cycle Science, $1,144,441, 2014-2017 PI Jingfeng Xiao, Co-Is Changsheng Li, Alexandra R. Contosta, Ruth K. Varner, Junmei Tang Human activities (e.g., urbanization, land use planning) have led to complex patterns of urban, suburban, agricultural, and forested landscapes. Ecosystems within these landscapes play an important role in climate regulation by acting as regulators of CO2 and other greenhouse gases and altering surface albedo and other biophysical properties. Although climate change policy initiatives often include incentives for land management activities that can offset warming, most have focused on enhanced carbon storage. Often not considered is the fact that these practices also bear climate consequences through other mechanisms (N2O and CH4 emissions, altered albedo, etc). Better understanding of the processes controlling the uptake, storage, and release of greenhouse gas emissions along urban to rural gradients is essential for evaluating how alternative patterns of land use interact with carbon cycling and climate change and how future land use change will influence carbon sequestration potential within these complex landscapes. The overarching goal of our work is to examine the interactions among carbon cycling, land use, and climate change in a human-dominated, mixed land use region that includes urban, suburban, agriculture, and forest land uses in southern New Hampshire. We plan to combine field measurements of carbon storage and greenhouse gas emissions (CO2, CH4, and N2O), an improved process-based biogeochemical model - DNDC (DeNitrification and DeComposition) designed to predict C fluxes and trace gas emissions, historical and projected land use change data derived from Landsat imagery and cellular automata/agent-based modeling, and high spectral resolution remote sensing data from NASA Airborne Visible/Infrared Imaging Spectrometer (AVIRIS). Our specific objectives designed to achieve the overarching goal are to: (1) Measure C pools and greenhouse gas emissions (CO2, CH4, and N2O) in urban, suburban, agricultural, and forested landscapes; (2) Improve and parameterize the DNDC (DeNitrification and DeComposition) model and validate model predictions; (3) Develop historical land use change data for the last three decades from Landsat imagery and projections of future land use change; (4) Generate spatially continuous predictions of C pools and greenhouse gas emissions using Urban-DNDC and assess how land use interacts with C cycling and climate change and how future land use change will influence carbon sequestration potential within these complex landscapes; and (5) Determine the net radiative forcing values (in w m-2) for the major greenhouse units using CO2 and climate change scenarios. |
