Vulnerability of the Asian typical steppe to grazing and climate change
Vulnerability of the Asian typical steppe to grazing and climate change
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DOI：
10.1023/b:clim.0000018513.60904.fe
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发表时间：
2004-04-01
期刊：
影响因子：
4.8
通讯作者：
Chen, ZZ
中科院分区：
文献类型：
--
作者：
Christensen, L;Coughenour, MB;Chen, ZZ
利用生态系统模型研究了内蒙古草原植被对气候变化和放牧的脆弱性。放牧是该地区土地利用的一种重要形式，但气候变化对放牧的影响存在不确定性。通过敏感性分析，研究了最低和最高温度升高、环境CO2和升高、降水增加或减少以及放牧对植被生产的影响。模拟结果表明，地上草本植物净初级产量对降水变化最为敏感。降水、温度和二氧化碳的增加对草本植物产量具有协同效应，然而，这些气候情景的急剧增加使该系统在放牧时容易从草本植物转向灌木为主的植被。降水减少对植被生长率有负面影响，在适度放牧条件下草本植物的生长是不可持续的。气候变化导致的时间生物量模式的变化对放牧管理具有潜在的重大影响，在气候变化的情况下，放牧管理需要改变，以保持系统的稳定性。
The vulnerability of grassland vegetation in Inner Mongolia to climate change and grazing was examined using an ecosystem model. Grazing is an important form of land use in this region, yet there are uncertainties as to how it will be affected by climate change. A sensitivity analysis was conducted to study the effects of increased minimum and maximum temperatures, ambient and elevated CO2, increased or decreased precipitation, and grazing on vegetation production. Simulations showed that herbaceous above ground net primary production was most sensitive to changes in precipitation levels. Combinations of increased precipitation, temperature, and CO2 had synergistic effects on herbaceous production, however drastic increases in these climate scenarios left the system vulnerable to shifts from herbaceous to shrub-dominated vegetation when grazed. Reduced precipitation had a negative effect on vegetation growth rates, thus herbaceous growth was not sustainable with moderate grazing. Shifts in temporal biomass patterns due to changed climate have potentially significant implications for grazing management, which will need to be altered under changing climate to maintain system stability.