Urban land-use impacts on composition and spatiotemporal variations in abundance and biomass of earthworm community

Abstract

Soil fauna can sensitively respond to alterations in soil environment induced by land-use changes. However, little is known about the impact of urban land-use changes on earthworm communities. In this study, three land-use types (i.e., forest, nursery and abandoned lands) were chosen to identify differences in diversity, abundance and biomass of earthworm community in Kunming City. Urban land-use had a pronounced difference in species composition, evenness and diversity of earthworm communities. Forest land had the highest density, biomass and diversity of the earthworm communities. Total abundance was dominated by endogeic species in nursery land (70%) and abandoned land (80%), whereas in the forest land, the earthworm community comprised epigeic, endogeic and anecic species. Temporal changes in earthworm density and biomass were also significantly affected by land-use change. Total density and biomass of earthworms in the forest and nursery lands were highest in September, but highest in the abandoned land in October. The influence of soil physicochemical properties on the earthworm density and biomass also varied with land-use types. Soil temperature significantly affected earthworm density and biomass in the three land-use types. Soil pH was positively correlated with earthworm biomass in the forest land, but negatively associated with earthworm density in the abandoned land. Soil organic matter was positively correlated only with density and biomass of earthworms in the nursery and abandoned lands. Our results suggest that the species composition, abundance and biomass of earthworm communities can be determined by the modification of soil properties associated with urban land-use type.