Gastauer Markus, Saporetti-Junior Amílcar Walter, Magnago Luiz Fernando Silva, Cavender-Bares Jeannine, Meira-Neto João Augusto Alves
Center of Environmental Research Floresta-Escola Av. Prof. Mario Palmério 1000 38200-000 Frutal MG Brazil.
Laboratory of Ecology and Evolution of Plants Universidade Federal de Viçosa 36570-000 Viçosa MG Brazil.
Ecol Evol. 2015 Oct 26;5(22):5272-5283. doi: 10.1002/ece3.1761. eCollection 2015 Nov.
Allopatric or sympatric speciation influence the degree to which closely related species coexist in different manners, altering the patterns of phylogenetic structure and turnover among and between communities. The objective of this study was to examine whether phylogenetic community structure and turnover in the Brazilian Atlantic Forest permit conclusions about the dominant process for the formation of extant angiosperm richness of tree species. Therefore, we analyzed phylogenetic community structure (MPD, MNTD) as well as taxonomic (Jaccard similarity) and phylogenetic turnover (betaMPD, betaMNTD) among and between 49 tree communities distributed among three different habitat types. Mean annual precipitation and mean annual temperature in each survey area were estimated. Phylogenetic community structure does not differ between habitat types, although MPD reduces with mean annual temperature. Jaccard similarity decreases and betaMNTD increases with spatial distance and environmental differences between study sites. Spatial distance explains the largest portions of variance in the data, indicating dispersal limitation and the spatial aggregation of recently formed taxa, as betaMNTD is related to more recent evolutionary events. betaMPD, that is related to deep evolutionary splits, shows no spatial or environmental pattern, indicating that older clades are equally distributed across the Brazilian Atlantic Forest. While similarity pattern indicates dispersal limitations, the spatial turnover of betaMNTD is consistent with a high degree of sympatric speciation generating extant diversity and endemism in the Brazilian Atlantic Forest. More comprehensive approaches are necessary to reduce spatial sampling bias, uncertainties regarding angiosperm diversification patterns and confirm sympatric speciation as the dominant generator for the formation of extant species diversity in the Brazilian Atlantic Forest.
异域或同域物种形成以不同方式影响近缘物种共存的程度，改变了群落内部和之间的系统发育结构及更替模式。本研究的目的是检验巴西大西洋森林中的系统发育群落结构和更替是否能让我们得出关于现存被子植物树种丰富度形成的主导过程的结论。因此，我们分析了分布在三种不同栖息地类型中的49个树木群落内部和之间的系统发育群落结构（MPD、MNTD）以及分类学（杰卡德相似度）和系统发育更替（betaMPD、betaMNTD）。估算了每个调查区域的年平均降水量和年平均温度。尽管MPD随年平均温度降低，但不同栖息地类型之间的系统发育群落结构并无差异。杰卡德相似度随空间距离以及研究地点之间的环境差异而降低，而betaMNTD则增加。空间距离解释了数据中最大比例的方差，表明存在扩散限制以及新形成类群的空间聚集，因为betaMNTD与更近的进化事件相关。与深度进化分支相关的betaMPD未显示出空间或环境模式，表明较古老的分支在巴西大西洋森林中分布均匀。虽然相似度模式表明存在扩散限制，但betaMNTD的空间更替与高度的同域物种形成一致，从而在巴西大西洋森林中产生了现存的多样性和特有性。需要更全面的方法来减少空间采样偏差、关于被子植物多样化模式的不确定性，并确认同域物种形成是巴西大西洋森林中现存物种多样性形成的主要原因。
