Work

Mycorrhizal Type and Soil Nitrogen Content Coregulate Foliar Nutrient Responses to Neighborhood Functional Dissimilarity in Subtropical Forests

Year: 2025

Type: article

Abstract: Foliar nitrogen (N) and phosphorus (P) concentrations are of critical importance to plant productivity. Despite global declines in plant diversity, their effects on tree foliar N and P dynamics remain uncertain, especially under different mycorrhizal types and soil nutrient conditions. Based on a large biodiversity experiment in subtropical China, we assessed how neighborhood species richness and functional dissimilarity influence foliar N and P concentrations across 794 tree individuals, comprising three arbuscular mycorrhizal (AM) and five ectomycorrhizal (EcM) tree species, along natural soil total N gradients. At the neighborhood scale, foliar nutrients were jointly influenced by functional dissimilarity, mycorrhizal type, and soil N availability. Among dissimilarity metrics, wood density (WD) dissimilarity was the strongest predictor. Specifically, functional dissimilarity consistently increased foliar N and P concentrations in AM trees across the soil total N level, whereas its effects on EcM trees shifted from positive to negative with increasing soil total N content. These diversity-driven increases in foliar P concentration were further associated with enhanced tree growth. Our findings demonstrate that mycorrhizal type and soil N availability jointly mediate effects of neighborhood diversity on tree foliar nutrient status, with foliar P concentration playing a pivotal role in driving productivity responses to biodiversity in subtropical forests.

Source: Plant Cell & Environment

DOI: 10.1111/pce.70243