Spatial ecology of soil nematodes: Perspectives from global to micro scales

Abstract

Abstract Soil spatial heterogeneity is a major determinant of biological diversity and functions. Among soil biota, nematodes are considered as excellent models for understanding spatial soil ecology due to their broad niche, with respect to diet, lifestyle and living habitat. Their distribution, community composition and functional diversity in heterogeneous environments provide insight into identification of factors that driving spatial heterogeneity of populations and activities of soil organisms. In this review, we synthesize current knowledge on spatial ecology of soil nematodes providing new testable hypotheses and proposing new directions for future research. We evaluate recent studies on the latitudinal patterns of soil nematodes and summarize key determinants of nematode spatial distribution from global to micro (millimeter) scales. We found that the relative contribution of drivers influencing nematode distribution varied across spatial scales, and soil properties (e.g., soil organic matter) that operate at all spatial scales were key drivers. We suggest that two biological interactions, i.e., nematode-prey interactions and nematode-host interactions, are the most important determinants of the patchy distribution of microbes and plants from micro to field scales. Future research directions should include study of vector-mediated dispersal ecology, distribution pattern of functional traits at large scales, global change-induced distribution of populations, diversity and functional traits. Overall, this review extends our knowledge of nematode spatial ecology and provides a research orientation for further investigation of soil spatial ecology to meet global challenges.