Leaf δ15N, δ13C and Their Associations with Soil Fungal Biodiversity, Ectomycorrhizal and Plant Pathogenic Abundance in Forest Ecosystems of China
Abstract Leaf δ15N and δ13C are important functional traits in biogeographic studies of forest ecosystems. However, little is known about their relationships with soil fungal biodiversity, ectomycorrhizal, and plant pathogen abundance at large scales. In this study, leaf and soil samples were collected from 33 forest reserves along a large range across China to explore the associations between leaf δ15N and δ13C and soil fungal biodiversity, ectomycorrhizal, and plant pathogen relative abundance using molecular and stable isotope techniques. We found large-scale biogeographic patterns for leaf δ15N, δ13C, soil fungal biodiversity, and ectomycorrhizal relative abundance. The soil-plant-microbial interaction may contribute to the variations in leaf δ15N, δ13C, and soil fungal communities across different types of forest ecosystems. Temperature and precipitation were the main factors affecting large-scale biogeographic patterns of latitude and longitude. Leaf δ15N was mainly affected by the relative abundance of ectomycorrhizal fungi and leaf δ13C was affected by the relative abundance of plant pathogens. Leaf δ15N and δ13C may be indicators reflecting soil fungal communities in forest ecosystems.