【美国大平原的温室气体排放】William J. Parton^a1 Myron P. Gutmann^b Emily R. Merchant^c Melannie D. Hartman^a Paul R. Adler^d Frederick M. McNeal^d and Susan M. Lutz^a. Measuring and mitigating agricultural greenhouse gas production in the US Great Plains 1870–2000. PNAS 2015 doi: 10.1073-pnas.1416499112

Abstract

The Great Plains region of the United States is an agricultural production center for the global market and as such an important source of greenhouse gas (GHG) emissions. This article uses historical agricultural census data and ecosystem models to estimate the magnitude of annual GHG fluxes from all agricultural sources (e.g. cropping livestock raising irrigation fertilizer production tractor use) in the Great Plains from 1870 to 2000. Here we show that carbon (C) released during the plow-out of native grasslands was the largest source of GHG emissions before 1930 whereas livestock production direct energy use and soil nitrous oxide emissions are currently the largest sources. Climatic factors mediate these emissions with cool and wet weather promoting C sequestration and hot and dry weather increasing GHG release. This analysis demonstrates the long-term ecosystem consequences of both historical and c