Effects of ant nesting on the spatiotemporal dynamics of soil easily oxidized organic carbon in Xishuangbanna tropical forests, China

Abstract

Ant nesting can form microhabitat and soil nutrient condition in their nests that is diffe-rent from the surrounding environment, thus having a crucial effect on the variation of soil easily oxidized organic carbon (EOC). In this study, the Mallotus paniculatus communities in Menglun Tropical Botanical Garden of Xishuangbanna, Chinese Academy of Sciences was taken as the research object. We compared the spatiotemporal distribution of soil EOC in ant nests and the refe-rence soils, and analyzed the relationship of the variation in soil EOC to the changes in soil physicochemical properties. The results showed that soil EOC in ant nests and the reference soils had a unimodal change trend with months. The order was ranked as June>September>March>December. The soil EOC decreased with the soil layers. The EOC was higher in 0-5 cm nest soils than in the refe-rence soils, while it was not significantly different in the 5-10 cm and 10-15 cm soil layers. Ant nesting increased soil temperature, soil organic carbon, soil easily oxidized organic carbon, soil microbial biomass carbon, total nitrogen, soil nitrate nitrogen and hydrolysis nitrogen, but reduced the soil water content and bulk density. The impacts of ant nesting on soil ammonium and pH was not significant. The soil organic carbon and microbial biomass carbon had crucial roles in regulating the spatiotemporal variation in EOC in ant nests and the reference soils, whereas the effects of soil temperature, soil water content, total nitrogen and nitrate nitrogen ranked the second. The ant nesting had a crucial effect on the spatiotemporal variations in easily oxidized organic carbon, mainly through changing the microhabitat (e.g., soil temperature and moisture) and soil nutrients (e.g., soil organic carbon and microbial biomass carbon) in Xishuangbanna tropical forests.