Using micrometeorological methods and modeling to determine greenhouse gas budgets over agricultural systems in the inland Pacific Northwest

摘要: Cropping systems can be net sources or net sinks of greenhouse gases (GHGs) depending on climate and management. Agriculture can be a sink for carbon dioxide (CO 2) if climate and management conditions are conducive for the build-up of soil organic matter. At the same time, agricultural soils are the main anthropogenic source of nitrous oxide (N 2 O), which is both a GHG and an ozone depleting substance. The work presented in this dissertation investigates the dynamics of CO 2 and N 2 O fluxes over terrestrial systems in the Pacific Northwest (PNW) using measurements and modeling. The first study used the eddy covariance micrometeorological method to monitor fluxes of CO 2 for two years at two agricultural sites representing the low-and high-end of the regional precipitation gradient. Combining the measured net ecosystem exchange of CO 2 with information on carbon (C) export during harvest, we …