伊犁河谷农田生态系统生产力水平对碳源汇的影响

目的]分析伊犁河谷农田生态系统碳源汇的变化趋势及农田生态系统碳源汇的影响因素,为农业产业结构调整和农业生产固碳减排提供科学依据。方法]以2004—2013年伊犁河谷农作物产量、播种面积、农业投入等相关统计数据为依据,采用碳转化系数的方法对伊犁河谷农田生态系统主要碳源汇进行测算。结果](1)近10a来,伊犁河谷农田生态系统碳吸收总量由2004年的2.32×106 t升到2013年的4.48×106 t,平均增长率为7.57%,单位播种面积碳吸收量也由2004年的7.54t/hm2上升到2013年9.27t/hm2,提高了0.23倍。碳吸收量与水稻、小麦、玉米、蔬菜总产量呈极显著相关与胡麻总产量呈显著负相关。(2)碳排放总量由2004年的2.24×105 t增加到2013年的4.02×105t,10a间增加了0.80倍。对农田生态系统碳排放总量贡献最大的因素为柴油和化肥投入。(3)近10a间,净碳吸收总量由2004年的2.10×106 t增至2013年的4.07×106 t,单位播种面积净碳吸收量由2004年的6.81t/hm2上升至2013年的8.44t/hm2,年均增速2.41%。结论]在伊犁河谷农业生产的高投入、高产出的模式下,其农田生态系统表现为碳汇系统。

Impacts of Farmland Ecosystem Productivity Level on Carbon Source and Sink in Iri Valley

Objective] This study is to analyze the carbon source and sink variation of agriculture ecosystem and its driving factors in Iri Valley in order to provide the scientific basis for agricultural structure adjustment and agricultural production of carbon emissions.Methods] Based on the statistical data of crop yield, planting area, agriculture inputs in the period from 2004 to 2013, the carbon coefficient, the amounts of carbon source and sink of agriculture ecosystem in Iri Valley were calculated.Results] (1) The total carbon absorption was increased from 2.32×10⁶ t in 2004 to 4.48×10⁶ t in 2013 with a rate of 7.57% each year. Carbon absorption per unit of sowing area was increased from 7.54 t/hm² in 2004 to 9.27 t/hm² in 2013 with the times of 0.23. The correlation analysis results showed that carbon absorption had significantly positive correlations with the yields of rice, wheat, corn and vegetables, while significantly negative correlation with the yield of linseed. (2) The total carbon emission was increased from 2.24×10⁵ t in 2004 to 4.02×10⁵ t in 2013, which increased by 0.80 times during the past 10 years. Diesel and fertilizer inputs were the most important factors that influenced carbon emission. (3) The net carbon absorption was increased from 2.10×10⁶ t in 2004 to 4.07×10⁶ t in 2013, and net carbon absorption per unit of sowing area was increased from 6.81 t/hm² in 2004 to 8.44 t/hm² in 2013 with a increasing rate of 2.41% each year.Conclusion] With the high input and output model, the agriculture ecosystem in Iri Valley showed as a carbon sink.