Environment and evolutionary history depict phylogenetic alpha and beta diversity in the Atlantic coastal white‐sand woodlands

• Published in: Journal of vegetation science Vol. 31; no. 4; pp. 634 - 645
• Main Authors: Massante, Jhonny Capichoni, Gerhold, Pille, Tanentzap, Andrew
• Format: Journal Article
• Language: English
• Published: Hoboken Wiley Subscription Services, Inc 01.07.2020
• Subjects: Atlantic forest domain; Biodiversity; Brazil; Climate change; climatic stability; Coastal environments; coastal plant communities; Dispersal; dispersal limitation; Ecological effects; Evolution; evolutionary history; Gondwana; Latitude; lineage pool; niche conservatism; Niches; phylogenetic diversity; phylogenetic turnover; Phylogenetics; Phylogeny; Plant diversity; Precipitation; Quaternary; Refugia; Restingas; Saline soils; Soil fertility; Species; Species diversity; Taxa; Temperature; Woodlands
• ISSN: 1100-9233; 1654-1103
• DOI: 10.1111/jvs.12900

Questions How do ecological and evolutionary processes affect the phylogenetic alpha and beta diversity of angiosperm tree assemblages in an evolutionarily young coastal environment? Location Coastal vegetation of the Brazilian Atlantic Forest Domain (restingas), spanning 20° of latitude. Methods We calculated phylogenetic alpha and beta diversity at deep and shallow levels for angiosperm tree species in 136 circular sites of 10 km diameter (hereafter assemblages). The metrics we used for alpha diversity were the mean pairwise distance (MPD) and mean nearest taxon distance (MNTD), and mean pairwise distance separating species in two assemblages (Dpw) and mean nearest taxon distance separating species in two assemblages (Dnn) for beta diversity. We then investigated the relationship between phylogenetic diversity, historical (Quaternary) and current climatic variables, and edaphic conditions along the latitudinal gradient. Results We found that MPD increased with precipitation and latitude. MNTD increased with modern‐day temperature, historical temperature instability and precipitation, and it was higher in more fertile and less saline soils. Dpw did not correlate either with geographic or environmental distances between assemblages. However, Dnn was strongly correlated with both geographic and environmental distances between assemblages. Conclusions The increase in MPD with precipitation and latitude suggests the presence of old Gondwanan lineages colonising restingas from refugia at higher latitudes. The increase in MNTD with modern‐day temperature, historical temperature instability, precipitation, and it being higher in more fertile and less saline soils indicates that the distance between phylogenetic closest relatives tends to increase in assemblages less affected by environmental filtering. Low Dpw suggests the presence of widespread lineages across restingas, whereas high Dnn may indicate niche conservatism and dispersal limitation of more derived lineages. Our results offer insights into how ecological and evolutionary processes act to shape current patterns of biodiversity in geologically young environments. We evaluate how the environment and evolutionary history influence the phylogenetic diversity of tree assemblages in the evolutionarily young Atlantic coastal white‐sand woodlands (restingas). We found that the number of species was highest in the central distribution range of restingas and that co‐existing species became more distantly related in the southernmost restingas. Overall, our results suggest that restingas could have undergone contrasting evolutionary history along their distributional range in Brazil.