Ecological network structure in response to community assembly processes over evolutionary time

The dynamical structure of ecological communities results from interactions among taxa that change with shifts in species composition in space and time. However, our ability to study the interplay of ecological and evolutionary processes on community assembly remains relatively unexplored due to the difficulty of measuring community structure over long temporal scales. Here, we made use of a geological chronosequence across the Hawaiian Islands, representing 50 years to 4.15 million years of ecosystem development, to sample 11 communities of arthropods and their associated plant taxa using semi-quantitative DNA metabarcoding. We then examined how ecological communities changed with community age by calculating quantitative network statistics for bipartite networks of arthropod-plant associations. The average number of interactions per species (linkage density), ratio of plant to arthropod species (vulnerability), and uniformity of energy flow (interaction evenness) increased significant...

生态群落的动态结构源自类群间的相互作用，而此类相互作用会随物种组成在空间与时间上的更替发生改变。然而，由于难以在长期时间尺度下测定群落结构，我们对生态与进化过程协同作用于群落构建的研究仍相对匮乏。本研究借助横跨夏威夷群岛的地质年代序列（geological chronosequence）——该序列涵盖了50年至415万年的生态系统发育历程——采用半定量DNA宏条形码（DNA metabarcoding）技术，对11个节肢动物群落及其关联植物类群开展了采样。随后，我们通过计算节肢动物-植物关联二部网络（bipartite networks）的量化网络统计指标，探究了生态群落随群落发育时长的变化规律。各物种平均互作数（连接密度（linkage density））、植物与节肢动物物种数之比（脆弱性（vulnerability））以及能量流动的均匀性（交互均匀度（interaction evenness））均显著上升……