Wu Chao Chao, Gao Xiao Ye, Hou Fu Jiang
State Key Laboratory of Grassland Agro-ecosystems/College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou 730020, China.
Ying Yong Sheng Tai Xue Bao. 2017 Oct;28(10):3341-3350. doi: 10.13287/j.1001-9332.201710.002.
The transition zone from the Loess Plateau to the Qinghai-Tibet Plateau is one of the regions with most dramatic changes in agricultural production mode and most sensitive response to the carbon balance effect. This paper analyzed the carbon balance of the agriculture system along the altitude gradient in Tongwei, Weiyuan and Xiahe counties. The results showed that with the increase of altitude, the carbon emission, carbon fixation and carbon sink capacity of crops per unit area decreased accordingly, while the average carbon emission, carbon fixation and carbon source capacity of each household in livestock system increased. The integrated crop-livestock production system changed from carbon sink to carbon source. The average carbon emission of each household rose with altitude, but the carbon fixation was the opposite. The change of percentage ofhousehold in the transition zone from the Loess Plateau to the Qinghai-Tibet Plateau with carbon balance could be fitted with Logistic equation. In the crop system of Tongwei, Weiyuan and Xiahe with the altitude increase, carbon emission at the inflection point where the household percentage accounted for 50.0% was 1491, 857 and 376 kg CE·household, and carbon fixation was 6187, 3872 and 778 kg CE·household, respectively. For the livestock system, carbon emission was 2218, 3725 and 49511 kg CE·household, and carbon fixation was 138, 230 and 2706 kg CE·household, respectively. For the integrated crop-livestock system, carbon emission was 3615, 4583 and 49918 kg CE·household, and carbon fixation was 6289, 4113 and 3819 kg CE·household, respectively, which could be the key point for the regulation of regional carbon balance.
黄土高原向青藏高原的过渡地带是农业生产方式变化最为剧烈、对碳平衡效应响应最为敏感的区域之一。本文分析了通渭县、渭源县和夏河县沿海拔梯度的农业系统碳平衡。结果表明，随着海拔升高，单位面积农作物的碳排放、碳固定和碳汇能力相应降低，而畜牧系统中每户的平均碳排放、碳固定和碳源能力增加。农牧结合生产系统从碳汇变为碳源。每户的平均碳排放随海拔升高而增加，但碳固定情况则相反。黄土高原向青藏高原过渡地带农户碳平衡变化百分比可用Logistic方程拟合。在通渭、渭源和夏河的作物系统中，随着海拔升高，农户百分比占50.0%的拐点处碳排放分别为1491、857和376 kg CE·户，碳固定分别为6187、3872和778 kg CE·户。对于畜牧系统，碳排放分别为2218、3725和49511 kg CE·户，碳固定分别为138、230和2706 kg CE·户。对于农牧结合系统，碳排放分别为3615、4583和49918 kg CE·户，碳固定分别为6289、4113和3819 kg CE·户，这些可能是区域碳平衡调控的关键点。
