河西绿洲农田生态系统碳源／汇的时空差异研究

 研究了１９４９－２００５年甘肃河西绿洲农田生态系统部分碳吸收、碳排放以及净碳汇，结果表明，１）１９４９－２００５年河西绿洲农田生态系统碳吸收呈阶段性增长趋势，碳吸收总量从１９４９年的２４．３９万ｔ增加到２００５年的２９８．３７万ｔ，净增加２７３．９８万ｔ，增长了１２．２３倍。２）１９４９－２００５年河西绿洲农田生态系统碳排放呈急剧增加的态势，从１９４９年的０．２５万ｔ增加到２００５年的７５．７０万ｔ，净增加７５．４５万ｔ，增长了３０２．８倍。其中肥料施用导致的间接碳排放所占比例最大，且增速最快；而农业机械带来的碳排放最低，保持较低水平，基本上呈持平状态。３）１９４９－２００５年河西绿洲农田生态系统净碳汇与碳吸收大致相同，也呈阶段性增长趋势，说明碳吸收明显大于碳排放，进而表明河西绿洲农田生态系统具有较强的碳汇功能，但是碳排放的增长速度远远超过了碳吸收，这种形势不容乐观。

Research on the temporal-spatial differences of carbon sources and sinks of farmland ecosystems of Hexi oasis in Gansu

Temporal-spatial differences of carbon sources and sinks of farmland ecosystems of Hexi oasis in Gansu in 1949-2005 were studied.1) Carbon absorption of farmland ecosystems showed an increasing trend from 243.9 thousand tons in 1949 to 2 983.7 thousand tons in 2005,a net increase of 2 739.8 thousand tons(a 12.23 fold increase).2) Carbon emissions from the farmland ecosystem of the Hexi oasis in Gansu in 1949-2005 showed a rapid,increasing trend from 2.5 thousand tons in 1949 to 757 thousand tons in 2005,a n...