The Role of Environmental Heterogeneity in the Seed Rain Pattern

ABSTRACT We focus on understanding the influence of environmental variables on ecological processes, and such a focus promotes an integrated view of forest ecological patterns. The following questions were made: Do variations in temperature, precipitation, litterfall deposition and light intensity influence the density and composition of seed rain in a stretch of the Montane Atlantic Rainforest? Is there a pattern for dispersal syndrome in Montane Atlantic,? Over a period of 12 months, the deposition patterns of seed rains were evaluated. Seed density and species richness correlated with temperature and precipitation, with species richness decreasing with increasing altitude and seed density increasing as a function of the light incidence. Seed rain followed a seasonal deposition pattern with higher seed density and species richness in the higher rainfall period. Increasing trend in seed density was found in mountainous areas with northern and northeastern aspects (higher light incidences).

摘要 本研究聚焦于解析环境变量对生态过程的影响，该研究视角有助于形成对森林生态格局的整合性认知。本研究提出如下科学问题：温度、降水量、枯落物沉降量与光照强度的变化，是否会对一段山地大西洋雨林（Montane Atlantic Rainforest）内的种子雨（seed rain）密度与组成产生影响？山地大西洋雨林中是否存在扩散综合征（dispersal syndrome）的分布格局？本研究于12个月的周期内，对种子雨的沉降格局开展了调查评估。结果显示，种子密度与物种丰富度均与温度、降水量呈显著相关：物种丰富度随海拔升高而降低，种子密度则随光照入射量的增加而升高。种子雨呈现季节性沉降规律，在降水充沛的时期，其种子密度与物种丰富度均更高。在北向与东北向（光照入射量更高）的山地生境中，种子密度呈现上升趋势。