Abstract
As one of the major agricultural production areas in the world, the United States (U.S.) Midwest plays a vital role in the global food supply and agricultural ecosystem services. Although significant efforts have been made in modeling the carbon cycle dynamics over this area, large uncertainty still exists in the previous simulations in terms of reproducing individual components of the carbon cycle and their responses to environmental variability. Here we evaluated the performance of an advanced agroecosystem model, ecosys, in simulating carbon budgets over the U.S. Midwest, considering both the magnitude of carbon flux/yield and its response to environmental (climate and soil) variability. We conducted model simulations and evaluations at 7 cropland eddy-covariance sites as well as over 293 counties of Illinois, Indiana, and Iowa in the U.S. Midwest. The site-level simulations showed that ecosys captured both the magnitude and seasonal patterns of carbon fluxes (i.e., net ecosystem carbon exchange (NEE), ecosystem gross primary production (GPP), and ecosystem respiration (Reco)), leaf area index (LAI), and dynamic plant carbon allocation processes, with R2 equal to 0.92, 0.87, 0.87, and 0.78 for GPP, NEE, Reco, and LAI, respectively across all the sites compared with the observations. For regional scale simulations, ecosys reproduced the spatial distribution and interannual variability of corn and soybean yields with the constraints of observed yields and a new remotely sensed GPP product, with R2 of multi-year averaged simulated and observed yield equal 0.83 and 0.80 for corn and soybean, respectively. The simulated responses of carbon cycle dynamics to environmental variability were consistent with that from the empirical observations at both site and regional scales. Our results demonstrated the applicability of ecosys in simulating the carbon cycle and soil carbon dynamics of the U.S. Midwestern agroecosystems under different climate and soil conditions.
| Original language | English (US) |
|---|---|
| Article number | 108521 |
| Journal | Agricultural and Forest Meteorology |
| Volume | 307 |
| DOIs | |
| State | Published - Sep 15 2021 |
Bibliographical note
Funding Information:Authors acknowledge the support from the National Science Foundation (NSF) Career Award (1847334), the Foundation for Food and Agriculture Research (FFAR) (Grant ID: 602757), DOE Advanced Research Projects Agency-Energy (ARPA-E) SMARTFARM program (DE-FOA-0002250), NASA Carbon Monitoring System Program (80NSSC18K0170), USDA National Institute of Food and Agriculture (NIFA) Program (2017-67013-26253 and Hatch), and Department of Energy (DOE) (25-1215-0208-006). The content of this publication is solely the responsibility of the authors and does not necessarily represent the official views of the FFAR. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof. We thank Andrew Suyker from University of Nebraska Lincoln for providing the crop growth data at the Nebraska Mead flux-tower sites, and Junrui Ni from University of Illinois for processing the USDA crop planting date data at Illinois, Iowa, and Indiana. We acknowledge the following AmeriFlux sites for their data records: US-Ne1, US-Ne1, US-Ne3, US-Bo1, US-Br1, US-Ib1, and US-Ro1. Funding for AmeriFlux data resources was provided by the U.S. DOE's Office of Science.
Funding Information:
Authors acknowledge the support from the National Science Foundation (NSF) Career Award ( 1847334 ), the Foundation for Food and Agriculture Research (FFAR) (Grant ID: 602757 ), DOE Advanced Research Projects Agency-Energy (ARPA-E) SMARTFARM program (DE-FOA-0002250), NASA Carbon Monitoring System Program (80NSSC18K0170), USDA National Institute of Food and Agriculture (NIFA) Program ( 2017-67013-26253 and Hatch), and Department of Energy (DOE) ( 25-1215-0208-006 ). The content of this publication is solely the responsibility of the authors and does not necessarily represent the official views of the FFAR. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof. We thank Andrew Suyker from University of Nebraska Lincoln for providing the crop growth data at the Nebraska Mead flux-tower sites, and Junrui Ni from University of Illinois for processing the USDA crop planting date data at Illinois, Iowa, and Indiana. We acknowledge the following AmeriFlux sites for their data records: US-Ne1, US-Ne1, US-Ne3, US-Bo1, US-Br1, US-Ib1, and US-Ro1. Funding for AmeriFlux data resources was provided by the U.S. DOE’s Office of Science.
Publisher Copyright:
© 2021
Keywords
- Agroecosystems
- Carbon fluxes
- Crop yield
- Ecosys
- Environmental variabilities
- U.S. Midwest
