生物群落物种丰度格局研究(SAD)是理解物种多样性决定机制的关键。这不仅关系到物种多样性的保护与恢复；更重要的是，它有助于厘清群落中各个物种之间错综复杂的相互关系，以及物质与能量在群落中的分配方式。SAD研究始于上世纪30年代，但在海洋生态学领域，该项研究相对薄弱，国内更鲜有报道。鉴于此，本项目的主要目标是，以南海浮游植物为例，运用分形理论建立符合实际群落的SAD经验模型，以期为解析南海浮游植物群落结构及其主控因子提供理论支撑和科学依据。据此，拟开展的研究工作如下：1)运用分形理论建立SAD经验模型；2)利用实测数据阐明南海浮游植物群落结构的基本特征；3)检验SAD分形模型的拟合效果，探究决定南海浮游植物SAD的主控因子。本项目的研究工作将理论生态学研究的最新进展，与南海海洋生态学研究的实际需求相结合，为最终解释物种多样性的决定机制，以及保护和利用南海生物多样性资源提供有益帮助。

The study of species abundance distribution (SAD) is the key of understanding what determines species diversity. The theoretical exploration of SAD relates to the maintenance and conservation of bio-diversity, and more importantly, it is conduced to clear off the complicated relationship amony species and the distribution of matter and energy in a community. The research on SAD began in the 1930s. However, SAD study in marine ecology is very rare, and it is almost empty for the ecology and oceanography in our country. Accordingly, in the following study, the main purpose is to construct a SAD model derived by fractal theory, which can be consist with the natural phytoplankton community in South China Sea (SCS). This fractal SAD model will provie a direct and convictive evidence for the analyzing community structure of phytoplankton in SCS, which is finally favorable for full understanding of community diversity. Thus, objectives are to 1) construct a fractal SAD model; 2) illustrate the pattern of phytoplankton SAD in SCS; 3) test the present fractal model and expound results of phytoplankton community structure in SCS. This study will combines the advance in theoretical ecology research and the real demand of marine ecology in SCS, which eventually contributes to the enrichment of theoretical community ecoloy and the development and preservation of bio-diversity resources in SCS.