Nutrient cycling by mound building termites in low fertility soils of semi-arid tropical Australia

Abstract

The capacity of three species of mound-building termites, Amitermes vitiosus Hill, Drepanotermes perniger (Froggatt), and Tumulitermes pastinator (Froggatt), to turn over plant nutrients was quantified in a semi-arid tropical woodland near Charters Towers in north-eastern Queensland. Various chemical attributes of the red and yellow earth soils, of low inherent fertility and unmodified by recent termite activity, are compared with those of the mounds of the three termite species and with the underlying, termite-modified soils. The mounds contain 21 Mg ha-l of soil, representing only 1% of the total mass of soil in the Al soil horizon but 5-7% of the plant nutrients in this system. Nutrients in the termite mounds, temporarily withheld from plant growth, are eventually returned to the soil surface by erosion of abandoned mounds. We estimate that the termites can turnover annually 300-400 kg ha-1 of soil material with nutrient levels 2-7 times that of the Al soil horizon.