陕西省农田生态系统碳源/汇研究

Research on carbon source and sink of farmland ecosystem in Shaanxi Province

以2000—2009年陕西省各市(区)农作物产量、耕地面积及农业投入等相关统计数据为依据,对陕西省农田生态系统碳源/汇进行了测算.分析了陕西省碳源/汇时空变化特征。结果表明:2000—2009年,陕西省农田生态系统碳吸收、碳排放及其单位面积碳吸收和碳排放均呈增加趋势,碳吸收明显大于碳排放,说明陕西省农田生态系统具有较强的碳汇功能;其中果蔬作物碳吸收比例上升明显,化肥施用带来的间接碳排放成为主要的碳排放源:2000—2009年陕西省农田生态系统的净碳汇量在波动中呈增长趋势,此外,农田生态系统的净碳汇量表现出与其自然地理状况相吻合的特征,即关中平原地区净碳汇量大于秦巴山地和陕北高原。

Based on the statistical data of crop yields, cultivated areas and agricultural inputs of Shaanxi Province from 2000 to 2009, the amounts of carbon sequestration and emission of the farmland ecosystem in Shaanxi were calculated, and the spatial-temporal variations of carbon sequestration and emission were analyzed. The results show that ： the amounts of total carbon sequestration, total carbon emission, carbon sequestration per unit area and emission per unit area all show a rising trend from 2000 to 2009. Carbon sequestration is much more than carbon emission, which means the farmland ecosystem is a strong carbon sink; the carbon sequestration proportion of fruit-vegetable crops show remarkable increasing, and carbon emitted from fertilizer using has been the most important carbon emission source. The net carbon sink size of farmland ecosystem in Shaanxi presents a raising curve with fluctuation from 2000 to 2009. Besides, the net carbon sink size in Guanzhong Plain is larger than that in Qin-ba Mountain and Shaanbei Plateau, which consistent with the physical geography status.