title: Effects of Erosion from Mounds of Different Termite Genera on Distinct Functional Grassland Types in an African Savannah.
abstract: A key aspect of savannah vegetation heterogeneity is mosaics formed by two functional grassland types, bunch grasslands, and grazing lawns. We investigated the role of termites, important ecosystem engineers, in creating high-nutrient patches in the form of grazing lawns. Some of the ways termites can contribute to grazing lawn development is through erosion of soil from aboveground mounds to the surrounding soil surface. This may alter the nutrient status of the surrounding soils. We hypothesize that the importance of this erosion varies with termite genera, depending on feeding strategy and mound type. To test this, we simulated erosion by applying mound soil from three termite genera (Macrotermes,Odontotermes, andTrinervitermes) in both a field experiment and a greenhouse experiment. In the greenhouse experiment, we found soils with the highest macro nutrient levels (formed byTrinervitermes) promoted the quality and biomass of both a lawn (Digitaria longiflora) and a bunch (Sporobolus pyramidalis) grass species. In the field we found that soils with the highest micro nutrient levels (formed byMacrotermes) showed the largest increase in cover of grazing lawn species. By linking the different nutrient availability of the mounds to the development of different grassland states, we conclude that the presence of termite mounds influences grassland mosaics, but that the type of mound plays a crucial role in determining the nature of the effects.
authors.affiliation: Community and Conservation Ecology Group, Centre for Ecological and Evolutionary Studies, University of Groningen, PO Box 11103, 9700 CC Groningen, The Netherlands ; Leopard Ecology and Conservation, Private Bag BR 7, Gaborone, Botswana.
authors.forename: Cleo M
authors.initials: CM
authors.lastname: Gosling
authors.affiliation: Centre for Ecological and Evolutionary Synthesis, Department of Biology, University of Oslo, PO Box 1066, Blindern, 0316 Oslo Norway.
authors.forename: Joris P G M
authors.initials: JP
authors.lastname: Cromsigt
authors.affiliation: Scientific Services, Kruger National Park, South African National Parks, Skukuza, 1350 South Africa.
authors.forename: Nokukhanya
authors.initials: N
authors.lastname: Mpanza
authors.affiliation: Community and Conservation Ecology Group, Centre for Ecological and Evolutionary Studies, University of Groningen, PO Box 11103, 9700 CC Groningen, The Netherlands.
authors.forename: Han
authors.initials: H
authors.lastname: Olff
keywords: Hluhluwe iMfolozi Park; Macrotermitinae; Nasutitermitinae; bunch grass; ecosystem engineers; heterogeneity; lawn grass; mound erosion; savannah; termites