Vincent de Leijster

8 Chapter 1 Human-induced pressure on the Earth’s resources is greater than ever before, and this pressure is still vastly growing. It has been estimated that approximately a third of the land is biophysically degraded (FAO, 2011), which is clear from the reduction in vegetation productivity, major biodiversity losses and the reduction in the supply of most ecosystem services (IPBES, 2019; IPCC, 2019; UNDP, 2019). In other words, the functionality of the land is significantly lower than optimal. Although the causes of land degradation are diverse, agricultural land management is clearly one of the main drivers, and at same time agriculture is also the sector that is most strongly affected by it (Nkonya & Mirzabaev, 2016). Land degradation has an extent of 10-60 Mkm 2 (IPCC, 2019), and it is expected to lead to economic losses of 6.3 to 10.6 trillion US dollar per year (ELD Initiative, 2015) and to affect the livelihoods of more than 1.3 billion people (UNDP, 2019). This is why we urgently need to restore degraded land by rehabilitating its biophysical functionality and its biocapacity to provide ecosystem services. The United Nations have recognized this and have declared the coming decade, 2021-2030, the ‘Decade on Ecosystem Restoration’ (United Nations, 2019). Moreover, 2011 saw the start of the multi-country initiative of the ‘Bonn Challenge’, which is aimed at restoring 350 million hectares of land before 2030. As agricultural landmanagement has a prominent role in land degradation processes, it is now increasingly targeted as a key element for land restoration (Foley et al., 2011). Agroecology has been proposed as an alternative to conventional agriculture as it not only produces the diserable food, fiber, fuel or timber, but also conserves and promotes biodiversity and favorable environmental conditions (FAO, 2018; Rosa-Schleich et al., 2019). However, there are still many gaps in the knowledge of the transition from conventional degrading agricultural management to a rehabilitating agricultural management. In this thesis I address knowledge gaps that relate to agroecological transitions in woody crop systems. More specifically, I examine the rehabilitation pathways of ecosystem services after agroecological interventions in woody crop systems, providing findings on the development of economic performance as a result of agroecological interventions, and about the incentives which can influence these economic developments. In the first chapter of this thesis, I start by introducing a variety of land management approaches in the agricultural sector and their implications for environmental and socio-economic conditions (1.1). Second, I introduce the concept of ecosystem services and explain why this concept can be used effectively to measure ecological performance of agroecosystems (1.2). Third, I explain which farming strategies and incentives may influence economic performance (1.3). Fourth, I present an agroecological transition model in which I combine the ecological and economic information related to agroecological interventions (1.4). Finally, I present the aim and research questions that I address in this thesis (1.5).