Contents lists available at ScienceDirect Ecosystem Services journal homepage: www.elsevier.com/locate/ecoser The economics of landscape restoration: Benefits of controlling bush encroachment and invasive plant species in South Africa and Namibia William Stafford a, ⁎ , Catherine Birch b , Hannes Etter c , Ryan Blanchard a , Shepherd Mudavanhu d , Per Angelstam e , James Blignaut f , Louwrens Ferreira g , Christo Marais g a Council for Scientific and Industrial Research (CSIR), Natural Resources and Environment unit, P.O. Box 320, Stellenbosch 7599, South Africa b Namibia Nature Foundation, P.O. Box 245, Windhoek, Namibia c Gesellschaft für internationale Zusammenarbeit (GIZ) GmbH, Germany d Department of Agricultural Economics, University of Stellenbosch, ASSET Research, South Africa e Swedish University of Agricultural Sciences, Faculty of Forest Sciences, School for Forest Management, Forest-Landscape-Society Network, SE-73921 Skinnskatteberg, Sweden f Department of Economics, SAEON, University of Pretoria, Pretoria, South Africa g Natural Resource Management programmes, Department Environmental Affairs, South Africa ARTICLE INFO Keywords: Invasive alien species Invasive alien plants Bush encroachment Economics land degradation Landscape restoration Ecosystem services ABSTRACT Bush encroachment and alien plant invasions alter the composition and/or balance of species in natural ecosystems and impact biodiversity, land productivity and water availability. Therefore, the appropriate control and management of bush encroachment and alien plant invasions can restore ecosystems services and enhance the provision of timber and non-timber products to society. To understand the economics of land impacted by bush encroachment and alien plant invasions, we valued a selected number of ecosystem services from landscape restoration in South Africa and Namibia. In Namibia, the estimated value of ecosystem services from the restoration of bush encroachment was US$5.8 billion. In South Africa, the estimated value of ecosystem services from the restoration of bush encroachment was US$2.1 billion, and US$6.6 billion from the restoration of alien plant invasions. The most valued ecosystem service benefit assessed was water, followed by timber products and wood-fuels such as biomass to electricity, and then grazing. The value of these ecosystem services are considerable compared to the direct costs involved to clear invasive alien plants and control bush encroachment. This clearly illustrates that the management of invasive alien plants and bush encroachment can deliver significant ecosystem services benefits whose value outweighs the costs of restoration. 1. Introduction Ecosystems deliver a wide range of benefits to society by providing, supporting and regulating services such as clean water, food and air (Costanza et al., 1997; De Groot et al., 2012). Despite the fact that all life depends on services derived from functional ecosystems, the Millennium Ecosystem Assessment (2005) revealed that over last 50 years approximately 60% of global ecosystem services have declined. In South Africa and Namibia, an important driver of ecosystem decline is bush encroachment and the spread of invasive alien plant species (Richardson, 1998, Richardson and Van Wilgen, 2004, Walker et al., 2004, Kraaij and Ward, 2006). Both bush encroachment and invasive alien plant species are known to compromise ecosystem function, and thereby reduce the ability to deliver a suite of ecosystem services that underpin economic productivity and sustainable development (Favretto et al., 2016; Reed et al., 2015). Bush encroachment is the invasion and/or thickening of aggressive undesired woody species resulting in an imbalance of the grass to bush ratio, a decrease in biodiversity, and a decrease in carrying capacity (De Klerk, 2004). Bush encroachment has an estimated extent of 26–30 million hectares in Namibia, and 10–20 million hectares in South Africa (Bester, 1999; Kraaij and Ward, 2006). The encroachment of woody plants in southern Africa occurs mainly in the grasslands and savannas (Kreuter et al., 1999; De Klerk, 2004; Ward, 2005; Dougill et al., 2016). The dominant species responsible for this encroachment are: Acacia mellifera, Acacia reficiens, Acacia tortilis, Acacia nilotica, Acacia karoo, Dichrostachys cinera, Termanalia sericia, Rhigozum trichotomum and Tarchonanthus camphoratus (Kraaij and Ward, http://dx.doi.org/10.1016/j.ecoser.2016.11.021 Received 26 April 2016; Received in revised form 3 August 2016; Accepted 26 November 2016 ⁎ Corresponding author. E-mail address: wstafford@csir.co.za (W. Stafford). Abbreviations: N$, Namibian dollars; US$, US dollars; ZAR, South African Rand; t, metric tonnes. All biomass expressed on a dry mass basis; ha, hectares. 1 ha=0.01 km 2 ; CO 2eq , greenhouse gas emission in carbon dioxide equivalents Ecosystem Services (xxxx) xxxx–xxxx 2212-0416/ © 2016 Published by Elsevier B.V. Please cite this article as: Stafford, W., Ecosystem Services (2017), http://dx.doi.org/10.1016/j.ecoser.2016.11.021