MOE Laboratory for Earth Surface Processes, Institute of Ecology, College of Urban and Environmental Sciences, Peking University, Beijing, 100871, China.
Institute of Ecological Environment, Chinese Research Academy of Environmental Sciences, Beijing, 100012, China.
Int J Biometeorol. 2023 Jun;67(6):1095-1104. doi: 10.1007/s00484-023-02481-9. Epub 2023 May 31.
Seed rain phenology (the start and end date of seed rain) is an essential component of plant phenology, critical for understanding population regeneration and community dynamics. However, intra- and inter-annual changes of seed rain phenology along environmental gradients have rarely been studied and the responses of seed rain phenology to climate variations are unclear. We monitored seed rain phenology of four forest communities in four years at different elevations (900 m, 1450 m, 1650 m, 1900 m a.s.l.) of a subtropical mountain in Central China. We analyzed the spatiotemporal patterns of seed rain phenology of 29 common woody plant species (total observed species in the seed rain), and related the phenological variations to seed number and climatic variables using mixed-effect models with the correlation matrix of phylogeny. We found that changes in the period length were mainly driven by the end rather than the start date. The end date and the period length of seed rain were significantly different between the mast and non-mast seeding years, while no significant elevation-related trend was detected in seed rain phenology variation. Seed number, mean temperature in spring (T), and winter (T), summer precipitation (P) had significant effects on seed rain phenology. When T increased, the start date of seed rain advanced, while the end date was delayed and the seed rain period length was mainly prolonged by a higher seed number, T and P. Forest canopy might have a buffering effect on understory climatic conditions, especially in precipitation that lead to difference in seed rain phenology between canopy and shrub species. Our novel evidence of seed rain phenology can improve prediction of community regeneration dynamics in responding to climate changes.
种子雨物候（种子雨开始和结束的日期）是植物物候学的一个重要组成部分，对于理解种群再生和群落动态至关重要。然而，种子雨物候沿环境梯度的年内和年际变化很少被研究，种子雨物候对气候变化的响应也不清楚。我们在华中地区一座亚热带山区的四个不同海拔高度（900 m、1450 m、1650 m、1900 m 海拔）的四个年份中监测了四个森林群落的种子雨物候。我们分析了 29 种常见木本植物（种子雨中观察到的总物种）的种子雨物候的时空格局，并使用混合效应模型和系统发育相关性矩阵，将物候变化与种子数量和气候变量相关联。我们发现，时期长度的变化主要是由结束日期而不是开始日期驱动的。种子雨的结束日期和时期长度在主年和非主年之间有显著差异，而在种子雨物候变化中没有检测到显著的海拔相关趋势。种子数量、春季平均温度（T）和冬季平均温度（T）、夏季降水（P）对种子雨物候有显著影响。当 T 升高时，种子雨的开始日期提前，而结束日期推迟，种子雨时期长度主要通过较高的种子数量、T 和 P 延长。林冠可能对林下气候条件具有缓冲作用，特别是在降水方面，这导致林冠和灌丛物种的种子雨物候存在差异。我们关于种子雨物候的新证据可以提高对气候变化下群落再生动态的预测能力。
