Nutrient‐based species selection is a prevalent driver of community assembly and functional trait space in tropical forests

Abstract

1. Soil nutrient availability and functional traits interact in complex ways during the assembly of tree communities hindering our understanding of the implications that this may have for their phylogenetic and functional diversity.2. We combined abundance, taxonomic, phylogenetic and functional trait data of 222 tree species distributed along nutrient concentration gradients at 24 plots in two tropical forest study sites. We analysed micro and macronutrient concentration in organic and topsoil horizons and tested for the following: (1) nutrientbased species sorting due to contrasting trait-environment relationships, (2) whether nutrient filtering has consequences for phylogenetic and functional diversity, and functional space size and occupancy and (3) we mapped trait distributions across the phylogeny of tree species to track the evolutionary signature of nutrient availability.3. We found that total nitrogen (N), available phosphorus and total potassium in soil accounted for 68% of the variation in tropical tree species community composition, with strong associations with nutrient concentration for 89% of the tree species included in the analysis. This nutrient-based species selection was mediated by interactions between the three soil nutrient concentrations with leaf nitrogen, leaf thickness and wood density. Soil N concentration was positively | 1219

Contrasting responses of fine root biomass and traits to large‐scale nitrogen and phosphorus addition in tropical forests in the Guiana shield

“…In addition to soil physical properties differences, total contents of soil C, N and P are around twice as high in Nouragues than in Paracou (Table 1). Total species richness (Table 1) and diversity are higher in Nouragues than in Paracou, with different aboveground (Peguero et al 2023) and belowground functional trait expression between sites (Table 1).…”

“…Nonetheless, N and P addition resulted in higher N and P contents in leaves, respectively, in Paracou, whilst in Nouragues, adding N and P together increased P contents but not N contents in leaves (Supporting information). Such divergent responses among nutrients and plant tissues could suggest that there might be a preferential N allocation aboveground, especially in the lower fertility site, Paracou (Peguero et al 2023).…”

“…Here, we aimed to understand the consequences of nutrient limitation affecting root nutrient acquisition mechanisms by conducting a large‐scale nutrient manipulation experiment in two tropical forests in French Guiana varying twofold in their soil nutrient statuses (Van Langenhove et al 2020a) and consequently in tree species richness and diversity (Peguero et al 2023). After three years of experiment, we specifically tested the potential effects of alleviating soil N and P limitations on various root properties, including root biomass, morphological traits and nutrient contents in root tissues.…”

“…Mean ± SE are presented. Tree species abundance and richness data fromPeguero et al (2023) (n = 24 plots; 12 plots per site). Soil and root data refer to samples from control-plots only (n = 6; three control plots per site in two seasons) collected in 2019.…”

Leaf functional diversity and environmental filtering in a tropical dry forest: Comparison between two geological substrates

“…Nutrient-based species selection is an important driver of community assembly, and community functional space size increases with soil nutrient concentrations (Peguero et al, 2023). Locally, substrate type and changes in elevation that affect soil depth, nutrient availability, and soil texture result in contrasting plant functional strategies (de Souza et al, 2023).…”