Abstract
Environmental filtering consistently shapes the functional and phylogenetic structure of species across space within diverse forests. However, poor descriptions of community functional and lineage distributions across space hamper the accurate understanding of coexistence mechanisms. We combined environmental variables and geographic space to explore how traits and lineages are filtered by environmental factors using extended RLQ and fourth-corner analyses across different spatial scales. The dispersion patterns of traits and lineages were also examined in a 20-ha tropical rainforest dynamics plot in southwest China. We found that environmental filtering was detected across all spatial scales except the largest scale (100 × 100 m). Generally, the associations between functional traits and environmental variables were more or less consistent across spatial scales. Species with high resource acquisition-related traits were associated with the resource-rich part of the plot across the different spatial scales, whereas resource-conserving functional traits were distributed in limited-resource environments. Furthermore, we found phylogenetic and functional clustering at all spatial scales. Similar functional strategies were also detected among distantly related species, suggesting that phylogenetic distance is not necessarily a proxy for functional distance. In summary, environmental filtering considerably structured the trait and lineage assemblages in this species-rich tropical rainforest.
Highlights
The extraordinarily high plant diversity in the tropics has fascinated ecologists for decades
The total nitrogen (TN), total phosphorus (TP), total potassium (TK), available nitrogen (AN), available phosphorus (AP), available potassium (AK), soil moisture, and elevation were significantly autocorrelated at all spatial scales
Environmental filtering was detected at all spatial scales, except 100 × 100 m, and this filtering considerably structured the functional strategies of lineages in a species-rich tropical rainforest
Summary
The extraordinarily high plant diversity in the tropics has fascinated ecologists for decades. Studies examining the impact of habitat on species distributions date back many decades, the habitat template hypothesis has often been tested using traditional taxonomic-based approaches[7, 8] These approaches may accurately describe spatial and temporal variation in species composition and structure under different environmental conditions. Trait-based ecology involves identifying the impacts of trait-mediated direct and indirect interactions among species in the community[11] In this regard, the distribution of plant functional traits www.nature.com/scientificreports/. To compare plants’ functional strategies along different environmental gradients and to possibly infer assembly mechanisms, linking traits with filtering factors is very important. It is essential to consider phylogenetic information on the trait-environment relationship to determine whether the functional strategies of species depend on evolutionary distance[18]. It is imperative to integrate traits, phylogenies, and the environment across the geographical space to gain a complete understanding of the underlying community assembly mechanisms
Sign-in/Register to view highlights & summary 
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call