陕南地区农田生态系统碳源/汇时空差异

The time and space differences of farmland ecosystem' carbon source/sink of Southern Shaanxi

对陕南农田生态系统碳源/汇进行研究,结论如下:碳汇量快速提高,碳源量变化平稳,净碳量与碳汇表现一致;碳汇量、碳源量、净碳汇量、净碳密度的空间分布基本一致,汉江河谷地带最高,沿河谷向两边递减,大巴山高于秦岭山地;丹江河谷中间地段峡谷深切,是各指标低值区,低值区外围环形分布的系列盆地各指标值较高;综合考虑农作物优生条件和农业比较利益,河谷地带适合大面积种植水果、蔬菜、玉米、水稻,丘陵坡地可适当种植油菜和薯类;发展生态农业,减少化肥施用量可达到减源增汇效果。

The carbon cycle research of farmland ecosystem is an important aspect of current global climate change research. The article studied the carbon source/sink of farmland ecosystem in Han river＇s upstream, and made the following collusions ： the rate of carbon source is rapid, while the change of carbon source quantity is steady, and net carbon source quantity is consistent with the carbon sink; the quantities of carbon sink, carbon source, net carbonization and net carbon density distributed consistently; the highest point laid in the Han river valley area, which declined to the both sides of the valley, and the carbon source is higher in Daba mountain than Qinling mountain; the lowest point is in the middle area of Danjiang river valley which has deep canyon, surrounding which the indexes in the basins laid out in circle are high; con- sider the healthy conditions of corps and the comparative profits of agriculture integrally, it is suitable for the planting of fruit, vegetables, maize, rice in the valley, and the planting of rape and potato, to minimize the carbon source and prove the collect through developing ecological agriculture by reducing chemical fertilizers.