Where do South-Indian termite mound soils come from?

摘要

This study investigated the origin of the soil termites used to build their above-ground mounds. Termite mounds were surveyed in a ferralsol and a vertisol in a dry deciduous forest in Karnataka, southern India. In these environments, two types of above-ground termite mounds are observed which we describe here as CATHEDRAL and LENTICULAR mounds. Partial Least Squares Regression models (PLSR) were computed from the physical and chemical properties of the soil sampled down to 4 and 2.5 m in the ferralsol and vertisol, respectively. Soils from CATHEDRAL mounds had the same signatures as soils collected at approximately 100 and 50 cm deep in the ferralsol and vertisol, respectively. On the other hand, soil from LENTICULAR mounds had the same signature as soil sampled at 30 and 60 cm deep in the ferralsol and vertisol, respectively. In conclusion, this study highlighted that the source of the soil termites use to build their mounds can be soil (ferralsol vs vertisol) and species (CATHEDRAL vs LENTICULAR) specific. In light of these findings, we conclude that the impact of CATHEDRAL mounds on soil dynamics appears to be smaller than that of LENTICULAR mounds in terms of soil volume at the landscape scale but it is higher in terms of soil translocation from deeper soil layers to the surface.