Termites: Soil engineers for ecological engineering

Abstract

This communication assesses advances in our knowledge of the beneficial influences of termites on ecosystem functioning and services. Termites are amongst the main macroinvertebrate decomposers in arid and semi-arid environments and exert additional impacts through the creation of biostructures (mounds, galleries, sheetings, etc.) with different soil physical and chemical properties. Unfortunately, the positive ‘or bright’ role of termites is often overshadowed by their dark side, i.e. their status as pests threatening agriculture in the tropics (635 vs. 164 articles referenced in WoS with termites and either pest or ecosystem engineer as keywords. Source: WoS, April 2019). Termite impacts on soil properties and water dynamics can be differentiated at four different scales: (i) at the landscape scale, where termites act as heterogeneity drivers; (ii) at the soil profile scale, where termites act as soil bioturbators; (iii) at the aggregate scale, where they act as aggregate reorganizers; (iv) and last, at the clay mineral scale, where they can act as weathering agents [1] . In this communication, two examples of ecosystem services provided by termites are given. The first describes the positive impact of termites on water infiltration and nutrient guidance at small scale through the production of foraging galleries in soil [2] and how this activity can be used to improve agro-ecosystem functioning in arid and semi-arid environments [3] . The second example deals with the construction of mounds and sheeting by termites in “natural” environments [4] and how these “patches of biodiversity and fertility” can be used in the lower Mekong Basin to reduce food insecurity and to provide a better access to health [5] ( Fig. 1 ). Finally, the perception of termite mounds in Southern Indian rural environments ( Fig. 2 ) is discussed and used as example of the cultural services that can be provided by termites in some circumstances. The story of Valmiki, the author of the Ramayana, is explained and used as a parable for highlighting the interconnection between the “bright” and “dark” sides of termites, and more generally that to get the bright we also need the dark.