MARCH 1999 Restoration Ecology Vol. 7 No. 1, pp. 33–41 33 © 1999 Society for Ecological Restoration Termite- and Mulch-Mediated Rehabilitation of Vegetation on Crusted Soil in West Africa A. Mando 1 L. Brussaard 2 L. Stroosnijder 3 Abstract The rehabilitation of vegetation on structurally crusted soils by triggering termite activity through mulch was studied on three soil types in northern Burkina Faso, West Africa. A split-plot design was used in a fenced environment for the experiment. Insecticide (Dieldrin) was used at a rate of 500 g a.i. (active ingredient)/ha to create nontermite and termite plots. Three mulch types consisting of straw ( Pennisetum pedicellatum ), woody material ( Pterocarpus lucens ), and a composite mulch (straw and woody material) applied at a rate of 3, 6, and 4 tons/ha, respectively, were used to trigger termite ac- tivity. The grasses and woody species on the plots were surveyed. Nontermite plots responded weakly to mulch treatments, but even in the first year vegetation estab- lished on termite  mulch plots. Termite activity re- sulted in the increase of plant cover, plant species num- ber, phytomass production, and rainfall use efficiency. Infiltrated water use efficiency and plant diversity were not statistically different among treatments during the first 2 years but were in the third. Woody species estab- lished only on termite plots. The three types of mulch plots showed greater vegetation development than bare plots, which remained bare throughout the experiment. Analysis of the termite and mulch interaction indicated that mulch plots without termites did not perform better than bare plots, especially in the case of woody plant re- generation. Vegetation rehabilitation was best with composite and straw mulches with termites, followed by woody mulch with termites; it was worst on bare plots. Introduction I n the Sahelian zone of West Africa, the combined ef- fect of soil organic matter depletion due to overgraz- ing, continuous cultivation, and the decrease in rainfall in the last 30 years (Table 1) has resulted in the increase of crusted and unproductive land. Such land is charac- terized by very low infiltration capacity, nutrient imbal- ance, reduced biodiversity, and very low to zero primary production. Until 20 years ago, the most common re- sponse to these phenomena was abandonment, but an ever-increasing population on ever-diminishing arable land resources has increased awareness of the urgent need to act, not only to curtail further degradation but also to restore the productivity of already degraded land. Therefore, people in this region are now attempting to develop a range of essentially physical and cultural mea- sures against degradation, such as constructing bands of stone lines, sowing grass, and planting trees. But all these attempts are seriously hampered by the crusted state of the degraded soil, which limits the infiltration necessary to enable land rehabilitation (Hien 1995). The hypothesis tested in this paper is that the presence of dry vegetal material on structurally crusted soil can trigger termite activity and may thereby improve soil in- filtration sufficiently to activate vegetation establishment. Termites are a major component of the soil fauna in the tropics (Lee & Wood 1971), and their importance in modi- fying soil properties is generally recognized (Lobry de Bruyn & Conacher 1990; Lavelle et al. 1992). When estab- lished on degraded soil, termites can improve soil physi- cal properties within a short time (Mando 1997 a ). They also play a key role in the decomposition process (Whit- ford et al. 1991). Yet, despite the relative abundance of in- formation on termite ecology, little is known of the effect of termite-mediated processes on ecosystem productivity. Our aim was to evaluate the extent to which termite- mediated processes in crusted soil can rehabilitate the vegetation. We investigated both vegetation structure and production dynamics. Methods Site Description The investigation was conducted near Bourzanga in northern Burkina Faso, West Africa (13 ° 26 ' 15  N and 1 Antenne Sahélienne, 01 BP 5385, Ouagadougou 01, Burkina Faso, email antenne@fasonet.bf 2 Wageningen Agricultural University, Terrestrial Ecology and Nature Conservation, Bornsesteeg 69, 6708 PD Wageningen, The Netherlands. 3 Wageningen Agricultural University, Erosion and Soil & Wa- ter Conservation, Nieuwe Kanaal 11, 6709 PA Wageningen, The Netherlands.