《巴黎协定》提出全球暖化程度在21世纪末相对工业革命前控制在2℃以内的目标。青藏高原高寒植被对全球变暖非常敏感,在2℃温升这个边界增温条件下研究高原植被对气候变化的响应关系到高原生态安全问题,有重大现实意义。本文基于CMIP5...《巴黎协定》提出全球暖化程度在21世纪末相对工业革命前控制在2℃以内的目标。青藏高原高寒植被对全球变暖非常敏感,在2℃温升这个边界增温条件下研究高原植被对气候变化的响应关系到高原生态安全问题,有重大现实意义。本文基于CMIP5多模式模拟预测结果研究了高原植被对2℃温升的响应,并探讨了高原植被对于气候因子变化的敏感性,得到主要结论如下:在全球2℃温升背景下,高原植被叶面积指数(Leaf Area Index, LAI)较历史参考期显著增加,高原变绿,其中高原中部LAI和植被碳存储增加最为显著,三江源是植被LAI增加较快的区域。增温后裸地面积迅速减少,植被覆盖率总体增加,大部分地区草地呈增加趋势,森林减少趋势变缓,说明在2℃温升期高原植被有所改善。在全球2℃温升背景下,高原植被覆盖率表现出对温度和降水率等气候因子更强的依赖性和敏感性,在增暖环境中,气温仍是影响高原植被生态系统变化的主控因子。展开更多
The investigation of the mechanisms of plant adaptation to stressor action is one of the leading directions of current biological studies. To understand the mechanism of salt tolerance of seabuckthom （Hippophae rhamn...The investigation of the mechanisms of plant adaptation to stressor action is one of the leading directions of current biological studies. To understand the mechanism of salt tolerance of seabuckthom （Hippophae rhamnoides L.） and identify its ability to cope with the salinity effect in the saline and extremely cold region of Qinghai, China, a test was conducted with two-year-old seedlings subjected to 0, 200, 400 and 600 mmol·L^-1 NaClsolutions for 30 d. The results show that with an increase in salinity, the biomass of H. rhamnoides seedlings clearly decreased. Leaf water potential （ψw） and relative water content （RWC） were significantly reduced under salinity, with severe water shortages appearing in leaves. At the same time, the total chlorophyll content declined markedly. When salinity increased and stress time prolonged, the net CO2 assimilation rate （A） significantly declined. Intercellular CO2 concentration （Ci） declined at first and was then followed by an increase over the stress time. We conclude that H. rhamnoides grown in the extremely cold and saline region of Qinghai has a certain resistance to salt, which can be planted at appropriate salinity levels.展开更多
文摘《巴黎协定》提出全球暖化程度在21世纪末相对工业革命前控制在2℃以内的目标。青藏高原高寒植被对全球变暖非常敏感,在2℃温升这个边界增温条件下研究高原植被对气候变化的响应关系到高原生态安全问题,有重大现实意义。本文基于CMIP5多模式模拟预测结果研究了高原植被对2℃温升的响应,并探讨了高原植被对于气候因子变化的敏感性,得到主要结论如下:在全球2℃温升背景下,高原植被叶面积指数(Leaf Area Index, LAI)较历史参考期显著增加,高原变绿,其中高原中部LAI和植被碳存储增加最为显著,三江源是植被LAI增加较快的区域。增温后裸地面积迅速减少,植被覆盖率总体增加,大部分地区草地呈增加趋势,森林减少趋势变缓,说明在2℃温升期高原植被有所改善。在全球2℃温升背景下,高原植被覆盖率表现出对温度和降水率等气候因子更强的依赖性和敏感性,在增暖环境中,气温仍是影响高原植被生态系统变化的主控因子。
基金supported by the Doctoral Program Foundation of Institutions of Higher Education of China (20070022028)the 11th Five Scientific & Technological Sustaining Research Program of China (2006BAD03A1203)
文摘The investigation of the mechanisms of plant adaptation to stressor action is one of the leading directions of current biological studies. To understand the mechanism of salt tolerance of seabuckthom （Hippophae rhamnoides L.） and identify its ability to cope with the salinity effect in the saline and extremely cold region of Qinghai, China, a test was conducted with two-year-old seedlings subjected to 0, 200, 400 and 600 mmol·L^-1 NaClsolutions for 30 d. The results show that with an increase in salinity, the biomass of H. rhamnoides seedlings clearly decreased. Leaf water potential （ψw） and relative water content （RWC） were significantly reduced under salinity, with severe water shortages appearing in leaves. At the same time, the total chlorophyll content declined markedly. When salinity increased and stress time prolonged, the net CO2 assimilation rate （A） significantly declined. Intercellular CO2 concentration （Ci） declined at first and was then followed by an increase over the stress time. We conclude that H. rhamnoides grown in the extremely cold and saline region of Qinghai has a certain resistance to salt, which can be planted at appropriate salinity levels.
