Lazzaro Lorenzo, Lastrucci Lorenzo, Viciani Daniele, Benesperi Renato, Gonnelli Vincenzo, Coppi Andrea
Department of Biology, University of Florence, Florence, Italy.
Natural History Museum, Botany, University of Florence, Florence, Italy.
PeerJ. 2020 Mar 11;8:e8683. doi: 10.7717/peerj.8683. eCollection 2020.
We studied the secondary succession in semi-natural grasslands (dry grasslands and hay meadows) located in the eastern side of the Tuscan Apennines (Tuscany, Central Italy). We compared these habitats, investigating: (i) the changes in species richness, composition and phylogenetic diversity during the succession; (ii) whether the trends in species loss and species turnover in taxonomic diversity matched those in phylogenetic diversity. We performed a stratified random sampling, in a full factorial design between habitat type and succession stage (60 sampled plots, 10 × 2 types of habitat × 3 stages of succession). We constructed a phylogenetic tree of the plant communities and compared the differences in taxonomic/phylogenetic α- and β-diversity between these two habitats and during their succession. We identified indicator species for each succession stage and habitat. Looking at α-diversity, both habitats displayed a decrease in species richness, with a random process of species selection in the earlier succession stages from the species regional pool. Nevertheless, in the latter stage of dry grasslands we recorded a shift towards phylogenetic overdispersion at the higher-level groups in the phylogenetic tree. In both habitats, while the richness decreased with succession stage, most species were replaced during the succession. However, the hay meadows were characterized by a higher rate of new species' ingression whereas the dry grasslands became dominated with . Accordingly, the two habitats showed similar features in phylogenetic β-diversity. The main component was true phylogenetic turnover, due to replacement of unique lineages along the succession. Nevertheless, in dry grasslands this trend is slightly higher than expected considering the major importance of difference in species richness of dry grasslands sites and this is due to the presence of a phylogenetically very distant species (.
我们研究了位于托斯卡纳亚平宁山脉东侧（意大利中部托斯卡纳）的半天然草地（干草原和干草甸）中的次生演替。我们对这些栖息地进行了比较，调查：（i）演替过程中物种丰富度、组成和系统发育多样性的变化；（ii）分类多样性中的物种丧失和物种更替趋势是否与系统发育多样性中的趋势相匹配。我们采用分层随机抽样，在栖息地类型和演替阶段之间进行全因子设计（60个采样地块，10×2种栖息地类型×3个演替阶段）。我们构建了植物群落的系统发育树，并比较了这两种栖息地及其演替过程中分类/系统发育α-和β-多样性的差异。我们确定了每个演替阶段和栖息地的指示物种。从α-多样性来看，两种栖息地的物种丰富度均有所下降，在演替早期阶段，物种从区域物种库中随机选择。然而，在干草原的后期阶段，我们在系统发育树的较高分类群中记录到向系统发育过度分散的转变。在两种栖息地中，虽然丰富度随着演替阶段而降低，但大多数物种在演替过程中被取代。然而，干草甸的特征是新物种迁入率较高，而干草原则以……为主导。因此，两种栖息地在系统发育β-多样性方面表现出相似的特征。主要成分是真正的系统发育更替，这是由于独特谱系在演替过程中的替代。然而，考虑到干草原地点物种丰富度差异的重要性，在干草原中这种趋势略高于预期，这是由于存在一个系统发育上非常遥远的物种（……）。
