Inter-annual Seed Rain Variability, Dispersal Limitation, Seed/Seedling Mortality in a SE Asian Rainforest: Implications for the Maintenance of Tree Diversity

这项研究将测试在马来西亚半岛的Pasoh研究森林的巨大多样性的东南亚雨林中，丰硕的果实是否对800多种树的共存具有重要意义。丰产是指多种树种在较短时间内同时落种的现象。肥大-结实期之间有3-9年的不规则间隔，很少或根本没有种子生产。在这些森林中，肥大的果实被认为是作为捕食者对重型哺乳动物种子捕食者的一种逃避反应而进化的。这项研究将严格地与巴拿马巴罗科罗拉多岛(BCI)一片新热带森林中种子雨和幼苗萌发的13年动态研究相媲美，该森林没有表现出丰硕的果实。种子诱捕器和苗木地块将部署在整个帕索森林。陷阱中的种子雨将在5年内每周量化每个树种的种子雨量。将在相邻的种子捕捉器和苗木地块之间比较物种丰度和组成。这将允许评估种子到幼苗过渡过程中种子和幼苗死亡因素的强度。密度和频率依赖性强的种子和幼苗死亡率是BCI站点的特征。尽管这些被认为是共存的主要机制，但尚不清楚这一现象是普遍的还是BCI所特有的。这项拟议的研究对于理解不同热带森林中的树木多样性是否由相同的机制维持至关重要。这些知识对于管理热带森林和保护它们的生物多样性很重要。

This research will test whether mast-fruiting is important to the coexistence of over 800 species of trees in a mega-diverse Southeast Asian rainforest at the Pasoh Research Forest in peninsular Malaysia. Mast-fruiting is the simultaneous seed drop of many tree species in a relatively short time. Periods of mast-fruiting are separated by irregular intervals of 3-9 years with little or no seed production. Mast-fruiting is thought to have evolved as a predator escape response to heavy mammalian seed predators in these forests. This study will be strictly comparable to a 13-year study of the dynamics of seed rain and seedling germination in a neotropical forest on Barro Colorado Island (BCI), Panama, which does not exhibit mast-fruiting. Seed traps and seedling plots will be deployed throughout the Pasoh Forest. Seed rain in the traps will be quantified each week for each tree species over a 5-year period. Species abundances and composition will be compared between adjacent seed traps and seedling plots. This will allow an evaluation of the strength of seed and seedling mortality factors during the seed to seedling transition. Strong density- and frequency-dependent seed and seedling mortality characterized the BCI site. Although these are considered good candidates as primary mechanisms of coexistence, it is unclear if the phenomenon is general or specific to BCI. The proposed research is critical for understanding if tree diversity in different tropical forests is maintained by the same mechanisms. This knowledge is important for managing tropical forests and preserving their biodiversity.