Winter wheat carbon exchange in Thuringia, Germany

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• 作者：Anthoni ; Peter M. ; Freibauer ; Annette ; Kolle ; Olaf ; Schulze ; Ernst-Detlef
• 关键词：Winter wheat ; Net ecosystem exchange ; Eddy covariance ; Roth-C model
• 刊名：Agricultural and Forest Meteorology
• 出版年：2004
• 出版时间：January 20, 2004
• 年：2004
• 卷：121
• 期：1-2
• 页码：55-67
• 全文大小：255 K

文摘

Eddy covariance measurements and estimates of biomass net primary production (NPP) in combination with soil carbon turnover modelled by the Roth-C model were used to assess the ecosystem carbon balance of an agricultural ecosystem in Thuringia, Germany, growing winter wheat in 2001. The eddy CO₂ flux measurements indicate an annual net ecosystem exchange (NEE) uptake in the range from −185 to −245g Cm⁻² per year. Main data analysis uncertainty in the annual NEE arises from night-time u^* screening, other effects (e.g. coordinate rotation scheme) have only a small influence on the annual NEE estimate. In agricultural ecosystems the fate of the carbon removed during harvest plays a role in the net biome production (NBP) of the ecosystem, where NBP is given by net ecosystem production (NEP=−NEE) minus non-respiratory losses of the ecosystem (e.g. harvest). Taking account of the carbon removed by the wheat harvest (290g Cm⁻²), the agricultural field becomes a source of carbon with a NBP in the order of −45 to −105g Cm⁻² per year. Annual carbon balance modelled with the Roth-C model also indicated that the ecosystem was a source for carbon (NBP −25 to −55g Cm⁻² per year). Based on the modelling most of carbon respired resulted from changes in the litter and fast soil organic matter pool. Also, the crop and management history, particularly the C input to soil in the previous year, significantly affect next year’s CO₂ exchange.