Impact of grassland contract policy on soil organic carbon losses from alpine grassland on the Qinghai-Tibetan Plateau
Impact of grassland contract policy on soil organic carbon losses from alpine grassland on the Qinghai-Tibetan Plateau
复制标题
草地承包政策对青藏高原高寒草地土壤有机碳流失的影响
DOI：
10.1111/sum.12387
复制
发表时间：
2017-12-01
影响因子：
3.8
通讯作者：
Feng, Q.
中科院分区：
文献类型：
--
作者：
Cao, J.;Gong, Y.;Feng, Q.
青藏高原土壤碳储量在全球碳收支中占有重要地位。20世纪90年代，实行集体草原承包政策，使传统的集体草原经营模式转变为两种新的经营模式：多户经营模式（MMP：几户共用而不封育的草地）和单户经营模式（SMP：一户封育而只供一户使用的草地）。2016年在青藏高原的50个MMP和54个SMP冬季牧场采样，以评估两种管理模式之间土壤有机碳（SOC）的差异。结果表明，平均SOC是显着更大的MMP下比SMP下，估计0.41 MgC/公顷/年的损失，由于SMP以下新的草地合同。根据政府的草地政策，四个草地利用方案的夏季和冬季牧场。我们发现，如果草原管理下SMP，可能的C损失范围在0.31x10（7）和6.15x10（7）Mg C/年整个青藏高原相对于MMP，这更接近于20世纪90年代前的草原管理。以前的碳损失估计只考虑了土地利用变化（有覆盖变化），忽略了土地管理模式变化（无覆盖变化）的影响。新的数据表明，青藏高原的C损失大于先前的估计，因此，草原承包政策应进行审查，并应鼓励SMP家庭团聚到MMP。这些发现不仅对青藏高原的土地管理战略具有潜在的影响，而且对全球其他可能存在这种做法的放牧地区也具有潜在的影响。
Carbon storage in the soils on the Qinghai-Tibetan Plateau plays a very important role in the global carbon budget. In the 1990s, a policy of contracting collective grasslands to smaller units was implemented, resulting in a change from the traditional collective grassland management to two new management patterns: a multi-household management pattern (MMP: grassland shared by several households without enclosures) and a single-household management pattern (SMP: grassland enclosed and used by only one household). In 2016, 50 MMP and 54 SMP winter pastures on the Qinghai-Tibetan Plateau were sampled to assess the differences in soil organic carbon (SOC) between the two management patterns. Results showed that average SOC was significantly greater under MMP than under SMP, with an estimated 0.41 MgC/ha/yr lost due to SMP following the new grassland contract. Based on the government's grassland policy, four grassland utilization scenarios were developed for both summer and winter pastures. We found that if the grassland were managed under SMP, likely C losses ranged between 0.31x10(7) and 6.15x10(7) Mg C/yr across the Qinghai-Tibetan Plateau relative to MMP, which more closely resembles pre-1990s grassland management. Previous estimates of C losses have only considered land use change (with cover change) and ignored the impacts driven by land management pattern changes (without cover change). The new data suggest that C losses from the Qinghai-Tibetan Plateau are greater than previously estimated, and therefore that the grassland contract policy should be reviewed and SMP households should be encouraged to reunite into the MMP. These findings have potential implications for land management strategies not only on the Qinghai-Tibetan Plateau but also other grazing regions globally where such practices may exist.