西双版纳望天树林种子雨9年动态

Nine-year seed rain dynamics in Parashorea chinensis forest in Xishuangbanna, Southwest China

种子雨是森林生态系统过程的重要组成部分。虽然国内外已有部分关于种子雨的研究,但多数集中在温带和亚热带地区,热带地区种子雨的长期监测研究仍显不足。为全面了解热带森林种子雨输入的数量动态和物种组成的长期规律,本文对我国西双版纳望天树(Parashoreachinensis)林群落水平上9年(2008年5月至2017年4月)的种子雨输入进行了研究。9年共收集到木本植物的种子226种8,993,224粒,其中大型种子(I-1型) 77种9,779粒;中型种子(I-2型)61种24,237粒;小型种子(I-3型)72种83,399粒;粒状微小种子(II-1型)13种1,215,235粒;粒状极小种子(II-2型) 1种7,244,667粒;细丝状种子(II-3型) 2种415,907粒。种子雨输入量排名前10位的优势种贡献了70%以上的种子数量。各类型种子的种子雨输入量均具有年际波动,呈"大小年"的交替变化,间隔期为1–2年,物种组成也呈现一定的年际差异。持续9年的监测中,每类型种子至少观察到了1次大年结实事件。

Seed rain patterns are a crucial influence on plant regeneration. Although it is very challenging to understand the dynamics of seed rain, long-term monitoring of seeds can provide useful insights. In this study, we monitored seed rain patterns of forests dominated by Parashorea chinensis in Xishuangbanna, Southwest China for nine years. We recorded 8,993,224 seeds belonging to 226 species, between May 2008 and April 2017. We categorized seeds of 77 species as large, 61 species as medium, 72 species as small, 13 species as tiny, 1 species as infinitesimally grainy seed and 2 species as filamentous. More than 70% of all seeds belong to the top 10 dominant species. Seeds of all types showed pronounced inter-annual variation for both seed number and species number. At least one mast seeding was observed for each of the seed type during nine years.