School of Earth and Environment INSTITUTE FOR CLIMATE AND ATMOSPHERIC SCIENCE Prof Andy Dougill (with Lawrence Akanyang, Jeremy Perkins, Mark Reed & Frank Eckardt... ) Ecological Findings Workshop on the Economics of Land Degradation (ELD) Sustainable Land Management in Kgalagadi Rangelands 8 th July, 2014

Ecological Changes & Management Participatory Rangeland Monitoring & Management: Kgalagadi Studies Participatory development of rangeland degradation indicators (Reed et al., 2008) & links to Management Guides translated to Setswana / Afrikaans (Reed & Dougill, 2010) Dynamic system model from integration of local & scientific knowledge (Dougill et al., 2010) enabling link to economic projections / sceanrios Limited uptake prevented progress as seen in communal rangelands of Namibia

Soil Carbon Storage & Flux Studies In-situ analysis of CO 2 fluxes between soil & atmosphere - applied for Kalahari sand (Thomas et al., 2011) & salt pans (Thomas et al., 2014) Findings show susceptibility of biological soil crusts to release of CO 2 with warming, drying & disturbance (grazing) Enhanced C storage predicted for Wildlife Management Areas where grazing levels remain lower & should be valued when considering Payment for Ecosystem Services schemes (Dougill et al., 2012) South Africa Botswana Namibia Kalahari Sands

ELD Ecological Study Design ELD Study provides dual-scale ecological assessments of links between land use, management & degradation in Kgalagadi District Farm-scale ecological analyses along ‘piosphere’ grazing gradients away from borehole waterpoints on communal grazing lands, private cattle ranches & private game ranches in March 2014 Landscape-scale analysis of remotely sensed data of vegetation cover (NDVI as measure of green biomass 2000 – 2013) & animal numbers (from 2012 national aerial animal census)

Ecological Findings 1 Below average rainfall in 2014 led to a high % of bare ground (70- 90%) & forb cover (5-20%) across all land uses, with temporal variability also shown clearly by NDVI anomalies by year

Ecological Findings 2 Widespread bush encroachement found across the semi-arid study sites with Acacia mellifera, Grewia flava & Dichrostachys cinerea cover & density increased at expense of perennial grass layer on which cattle production is based Bush encroachment extensive across communal grazing areas & private cattle ranches displaying that privatisation is not directly leading to more sustainable land management

Ecological Findings 3 For arid sites in the SW, Rhigozum trichotomum forms impenetrable thickets close to boreholes, but otherwise bush encroachment absent Dune instability occurs to a distance of c. 1.2km from boreholes following the removal of Stipagrostis amabilis grass cover Ecological change pressures observed around Molopo river where the exotic Prosopis glandulosa observed & blamed locally for declining soil moisture & groundwater levels & expensive to remove

Ecological Findings 4 Regional patterns of key wildlife species (eland, wildebeest) shows that the expansion of cattleposts & fenced ranches has led to large areas of southern Kgalagadi with low biodiversity even where cattle production not practiced

Conclusions Dual-scale ecological analyses add new insights into rangeland degradation problems of arid and semi-arid Kgalagadi rangelands Bush encroachment (semi-arid) & dune mobilisation (arid) are most notable forms of land degradation linked to shifts in land use towards more widespread intensive cattle grazing & have impacts on reduced biodiversity & soil C storage Land tenure changes (to private ownership) have not prevented rangeland degradation across Kalahari Sustainable land management practices & rehabilitation options available by integration of local & scientific knowledges locally if facilitated together with landscape-scale land use planning regionally to ensure heterogeneity in, & connectivity of, land Full