Anthropogenic activities such as land-use change and agricultural management have altered terrestrial biogenic greenhouse gas (GHG) fluxes. Global carbon (C) emission associated with land cover and land use change (LUCC) was estimated with a large uncertainty, which is the most uncertain term in the C budget estimation at both global and regional scales. To better manage agroecosystem, it is of critical importance to comprehensively and accurately quantify the magnitude and spatiotemporal patterns of terrestrial C storage and sequestration capacity. In this study, based on state- and national census, field experiments, and model simulation, we comprehensively examined long-term carbon storage change in response to LUCC and agricultural management in the Midwest from 1850 to 2015.
Model estimation showed LUCC led to a reduction of 1.35 Pg (with a range of 1.3-1.4 Pg) in vegetation C pool of the Midwest, yet agricultural management barely affected vegetation C change.
In comparison, LUCC reduced SOC by 4.5 Pg (3.1 to 6.2 Pg), while agricultural management practices increased SOC stock by 0.9 Pg.
Our results imply that proper land management practices can potentially contribute to strengthen carbon sequestration of the terrestrial ecosystems in Midwestern U.S., which may serve as a major contributor to carbon sinks in the U.S. In addition, our study brings forth insightful points for accurate C budget assessment and management in intensively managed landscape.
This study has been featured by ISU News: Iowa State University researchers model how Midwestern land-use changes affect carbon storage over the last 165 years.