PDF(Pubmed)
Abstract：
Assessing plant diversity during community succession based on plant trait and phylogenetic features within a community (alpha scale) and among communities (beta scale) could improve our understanding of community succession mechanism. However, whether changes of community functional diversity at alpha and beta scale are structured by different traits and whether integrating plant traits and phylogeny can enhance the ability in detecting diversity pattern have not been studied in detail. Thirty plots representing different successional stages were established on the Loess Plateau of China and 15 functional traits were measured for all coexisting species. We first analyzed the functional alpha and beta diversity along succession by decomposing species trait into alpha and beta components and then integrated key traits with phylogenetic information to explore their roles in shaping species turnover during community succession. We found that functional alpha diversity increased along successional stages and was structured by morphological traits, while beta diversity decreased during succession and was more structured by stoichiometry traits. Phylogenetic alpha diversity showed congruent pattern with functional alpha diversity because of phylogenetic conservation of trait alpha components (variation within community), while beta diversity showed incongruent pattern due to phylogenetic randomness of trait beta components (variation among communities). Furthermore, only integrating relatively conserved traits (plant height and seed mass) and phylogenetic information can raise the detecting ability in assessing diversity change. Overall, our results reveal the increasing niche differentiation within community and functional convergence among communities with succession process, indicating the importance of matching traits with scale in studying community functional diversity and the asymmetry of traits and phylogeny in reflecting species ecological differences under long-term selection pressures.
摘要：
根据社区内（α尺度）和社区之间（β尺度）的植物性状和系统发育特征评估社区演替过程中的植物多样性可以提高我们对社区演替机制的理解。然而,群落功能多样性在α和β尺度上的变化是否由不同的性状构成，以及整合植物性状和系统发育是否可以增强多样性模式的检测能力，还没有详细研究。在中国黄土高原建立了30个代表不同演替阶段的地块，并测量了所有共存物种的15个功能性状。我们首先通过将物种性状分解为α和β成分来分析演替过程中的功能性α和β多样性，然后将关键性状与系统发育信息整合，以探索它们在社区演替过程中形成物种周转中的作用。我们发现功能α多样性在演替阶段增加，并由形态特征构成，而β多样性在演替过程中降低，并且更多地由化学计量特征构成。由于性状α成分的系统发育保守性（群落内的变异），系统发育α多样性显示出与功能α多样性一致的模式，而由于性状β成分的系统发育随机性（群落间的变异），β多样性显示出不一致的模式。此外，只有整合相对保守的性状（株高和种子质量）和系统发育信息，才能提高评估多样性变化的检测能力。总的来说,我们的结果表明，随着演替过程，群落内部的生态位分化和群落之间的功能趋同增加，说明了在长期选择压力下，性状与尺度匹配在研究群落功能多样性方面的重要性以及性状和系统发育的不对称性在反映物种生态差异方面的重要性。
