模拟增温引发的早春冻害：以岷江冷杉为例

以全球变暖为主要特征的全球气候变化已经并正在改变着陆地生态系统的结构和功能.现存植被与环境间的关系是经过漫长自然选择而形成的,因此植物物候变化可能会影响物种与环境间的相互关系.采用开顶式生长室(Open-top chamber,OTC)和移地试验(transposing of surface soil with vegetation,TSSV)模拟增温的方法,研究了川西亚高山岷江冷杉幼苗物候和冻害对模拟增温的短期响应.结果表明,生长季中OTC内日平均气温较对照增加2.2 ℃,高海拔(3 200 m)比低海拔(2 600 m)日平均温度低2.5 ℃.在两种研究方法下,温度升高都使岷江冷杉芽开放提前,休眠期推迟,生长季延长.温度升高使岷江冷杉幼苗新生芽遭受严重的冻害.结果表明,在未来全球气候变化的背景下,高海拔物种遭受早春冻害的可能性大.

Freezing damage in early spring induced by simulated global warming: a case study in Abies faxoniana

Global climate change mainly characterized by global warming had changed and been changing the structure and function of terrestrial ecosystem. The relationships between current vegetations and environments are formed through hundreds of thousands of years′ evolution, thus changes in plant phenology may influence these subtle relationships. In this study, the short-term responses of leaf phenology, freezing damage of Abies faxoniana to simulated global warming were investigated using the open-top chamber (OTC) and transposing of surface soil with vegetation (TSSV) methods. The results were shown as follows: In Muyangchang, mean air temperature in the OTC raised by 2.2 ℃ at 1.0 m above the ground in the OTC during the growing season. Moreover, mean air temperature was 2.5 ℃ lower in timberline ecotone (3200 m) than versus in Muyangchang (2600 m). A. faxoniana seedlings in warming treatments showed earlier bud break, later bud dormancy and longer growing season. Unfortunately, severe freezing damage in current buds was detected in warming treatments. The results obtained in this study indicate that frost damage probably poses strong impact on the alpine species under future warming conditions.