草地植物物候研究进展及其存在的问题

Phenology of grassland plants: A mini review

植物物候是随环境变化表现出的周期性节律变化的事件,对环境变化非常敏感。多数研究发现,增温改变了单个物候事件,如提前了返青期和开花期,推迟了枯黄期;特别是近期发现相对于其他物候序列而言,结实期保持相对稳定,并且物候序列持续期的反应存在等级关系。不同植物个体物候对环境变化的响应模式不同,因而依据植物个体物候很难准确预测群落物候对环境变化的响应模式,所以应该加强群落物候的地面观测研究。尽管放牧是天然草地的主要利用方式,但目前仍然缺乏放牧如何影响气候变化对物候序列影响的研究;尤其是由于研究方法和技术等限制,也缺乏未来气候变化条件下地上与地下物候同步性、物候变化非线性及其机理的研究。

Plant phenology is a periodic event with environmental change, being much sensitive to environmental change. Most of the studies have observed that warming advanced onsets of green-up and flowering, but delayed completely leaf coloring. However, fruiting-set kept relative stable under temperature change compared with other phenological sequences. There were hierar- chical responses of phenological sequences in duration to temperature change （i.e. warming and cooling）. In particular, more attention should be paid to observation of community phenology un- der future climate change because the response of individual plant phenology to climate change could not predict the response of the community phenology due to different responses from differ- ent plants. Although grazing is a major land use for natural grasslands, how grazing affects the effects of climate change on plant and community phenology is still unclear. Meanwhile, few stud- ies have been performed on the synchrony of aboveground and root phenology, non-linear change of phenological sequences and its mechanisms due to experimental method and technology limita- tions under future climate change.