Effect of grazing on carbon stocks and assimilate partitioning in a Tibetan montane pasture revealed by 13CO2 pulse labeling
Effect of grazing on carbon stocks and assimilate partitioning in a Tibetan montane pasture revealed by 13CO2 pulse labeling
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DOI：
10.1111/j.1365-2486.2011.02557.x
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发表时间：
2012-02-01
影响因子：
11.6
通讯作者：
Kuzyakov, Yakov
中科院分区：
文献类型：
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作者：
Hafner, Silke;Unteregelsbacher, Sebastian;Kuzyakov, Yakov
自20世纪50年代后期以来，政府的草地政策改变了青藏高原（TP）的放牧管理。放牧压力的增加以及自1980年代以来村庄附近牧场的私有化和围栏化导致土地退化，而偏远牧场则从过度放牧中恢复过来。为了阐明适度放牧对TP碳（C）循环的影响，我们采用原位13CO2脉冲标记技术研究了（i）适度放牧的高山嵩草牦牛冬季牧场和（ii）7年生放牧围封区（均位于海拔3440 m）地下C储量和C分配的差异。标记后27天，13 C纳入芽之间没有不同的放牧（43%的恢复13 C）和未放牧（38%）的地块。然而，在放牧地块，少C失去了拍摄呼吸（17%比42%），更多的是转移到地下（40%比20%）。在地下水池中，
Since the late 1950s, governmental rangeland policies have changed the grazing management on the Tibetan Plateau (TP). Increasing grazing pressure and, since the 1980s, the privatization and fencing of pastures near villages has led to land degradation, whereas remote pastures have recovered from stronger overgrazing. To clarify the effect of moderate grazing on the carbon (C) cycle of the TP, we investigated differences in below-ground C stocks and C allocation using in situ 13CO2 pulse labeling of (i) a montane Kobresia winter pasture of yaks, with moderate grazing regime and (ii) a 7-year-old grazing exclosure plot, both in 3440 m asl. Twenty-seven days after the labeling, 13C incorporated into shoots did not differ between the grazed (43% of recovered 13C) and ungrazed (38%) plots. In the grazed plots, however, less C was lost by shoot respiration (17% vs. 42%), and more was translocated below-ground (40% vs. 20%). Within the below-ground pools,