Relationships among distribution of fine roots, soil DOC concentration and Collembola

Abstract

The higher abundance of microarthropods around plant roots has been considered to result from the release of labile carbon by roots (e.g., root exudation), but the concentration of labile carbon itself has not been measured. We investigated whether fine root distribution affects distribution of Collembola (Folsomia candida) by changing the soil dissolved organic carbon (DOC) concentration, which is supposed to represent rhizodeposits, under both low-and highlight conditions using a sandy soil system with Chamaecyparis obtusa. Fine root biomass and total DOC content were greater under the highlight condition than under the low-light condition, but no significant difference was detected in collembolan abundance. In addition, soil DOC concentration was correlated with fine root biomass, but collembolan distribution was not affected by root or DOC distribution under either light condition. Although it remains unsolved why collembolan distribution did not correspond to the fine-root or DOC distribution, our results indicate that there is the case of no significant correlation between roots and Collembola.