图1. 两种经典的群落结构。这里的矩阵展示了群落结构: 每一列代表不同植物, 而每一行代表了不同的授粉种(图A)或者草食动物(图B)。灰色的格子代表两个物种存在种间关系, 而白色的格子则代表不存在。图A展示了嵌套性结构。基于一个物种的种间关系的相对数量, 可以把物种分为泛化种(generalist)和特化种(specialist)。嵌套性结构的特征是认为泛化种会和泛化种以及特化种都相互作用, 而特化种几乎只和泛化种相互作用。嵌套性结构被认为是互利群落的一种普适结构。图B展示了模块化结构。模块化结构的特征是群落分成几个模块, 物种几乎只和同一模块的物种相互作用, 而很少和别的模块的物种相互作用。嵌套性结构被认为是食物网的一种普适结构。

Fig. 1. Two ecological community structures. Here we present an illustration of two hypothetical network structures. The community structure is represented as a matrix. The columns correspond to different plant species while the rows correspond to different pollinators (in Panel A) or herbivores (in Panel B). A species interaction is represented as a gray grid. Panel (A) illustrates the nested structure. The defining feature of a nested structure is that highly connected species interact with both highly connected and poorly connected species, while poorly connected species interact almost exclusively with highly connected species. The nested structure is widely conceived as a universal structure in mutualistic communities. Panel (B) illustrates the modular structure. The defining feature of the modular structure is that in which groups of species have many interactions among them, but few interactions with the rest of the species in the network. The modular structure is widely conceived as a universal structure in food webs.