Nutrient enrichment of ecosystems by fungus-growing versus non-fungus-growing termites

Abstract

Abstract:Fungus-growing termites (Macrotermitinae) collect water to air-condition their fungi and have been recorded tunnelling deeper than 80 m for groundwater. This collection of water ultimately results in solute accumulation and nutrient enrichment of their termitaria. We consequently hypothesized that nutrient enrichment of termitaria constructed by fungus-growing termites would be greater than by non-fungus-growing termites. To test this, we compared nutrient enrichment of termitaria of fungus-growingMacrotermesspp. in Namibia and termitaria of two non-fungus-growing termites –Trinervitermes trinervoidesin South Africa andNasutitermes triodiaein Australia. Compared with adjacent topsoils,Macrotermestermitaria were significantly enriched in 18 elements whereasT. trinervoidesandN. triodiaetermitaria were enriched in only one and five elements, respectively. Nutrients particularly enriched inMacrotermitestermitaria included Ca (an enrichment factor of 12), Mg (2.9), Co (2.8), Fe (2.4), Mn (2.3), Se (2.2) and Cu (2.0). We suggest that fungus-growing termites that collect water for air-conditioning their fungi have the potential to inadvertently boost – to a far greater degree than non-fungus-growing termites – the availability of nutrients to local plants and herbivores.