Understanding the drivers of deforestation and agricultural transformations in the Northwestern uplands of Cambodia

Highlights

• A 60 percent increase of agricultural land occurred between 2006 and 2016.

• Political stabilization and rural migration drove agricultural expansion.

• Crop diversification was driven by productivity decline and market uncertainties.

• Agroecology-based interventions may break the cycle of crop boom-bust.

Abstract

At the end of the 1990s, the Northwestern uplands of Cambodia were one of the last forest frontiers of the country. In a region that was the last Khmer Rouge stronghold, the opening of former conflict zones after a peace agreement initiated a vast movement of agricultural colonization. This movement was economically triggered by high market demand for agricultural commodities such as maize and cassava and fueled by a massive flow of spontaneous in-migration of land-poor farmers from lowland regions around the entire country. Focused on four upland districts along a pioneer front of Northwestern Cambodia, we analyzed historical trajectories of land use/cover changes using a chronological series of Landsat data from 1976 to 2016. We identified key drivers of deforestation using demographic data and qualitative information from local actors and other relevant stakeholders. We found a 65 percent forest cover loss due to conversion by smallholders into agricultural land for maize and cassava cultivation over a period of 15 years. The underlying mechanisms of land use change were further investigated to understand the diversity of individual farm trajectories and decision-making processes in relation to land conversion. These elements of diagnosis are essential to engage farming communities in innovative land use systems and to develop sustainable alternatives to boom crops that have led to the current situation of land degradation and economic instability.

Introduction

Tropical deforestation stands out as a key feature of global land use changes (Hansen et al., 2013) although the arguments advanced to explain it are usually far from conclusive (Lambin et al., 2001). The factors and pathways driving deforestation are indeed intricate and result from multiple factors, both local and regional, originating from different levels of organization and acting in various combinations in different locations (Geist & Lambin, 2002).

In Cambodia, deforestation is associated with both rapid economic growth and agricultural expansion (Diepart & Sem, 2015) reflecting the emergence of boom crops all across Southeast Asia (Hall, 2011). Recent waves of deforestation have been quantified and documented, although mainly in relation with the development of agro-industrial plantations granted as economic land concessions on state land (Davis, Yu, Rulli, Pichdara, & D'Odorico, 2015; Fella, Barua, Tamminen, & Hatcher, 2017). Little is known about other forms of forest conversion, particularly those produced by migrant smallholder farmers that are prevalent in the Northwestern corner of the kingdom. There, agricultural expansion into forested upland margins has led to the emergence of new agrarian systems mainly based on annual crops such as maize, cassava, peanut, and soybean. In Pailin and Battambang Provinces as a whole, the area of these crops increased six fold between 2001 and 2015, from 40,000ha to 250,000ha in 2015 (MAFF, 2001, 2015).

The region was the cradle of the Khmer Rouge (KR) uprising in the sixties and the rear base of their resistance against governmental forces in the eighties and nineties. In this region, the KR reintegration policy had designated new settlement and administrative areas in which KR soldiers were allowed to resettle and where their representatives were given responsibilities in land management. The subsequent allocation of forested land to demobilized soldiers and their families then marked the opening of the agricultural frontier, which created incentives for further migration (Diepart & Dupuis, 2014).

A first body of literature looking at agrarian changes in the region focuses on the political economy of land governance. It argues that land has emerged as common ground between a moving population and the combatant forces seeking to control them with a legitimized use of force (Pilgrim, Ngin, & Diepart, 2012). It also suggests that the struggles between KR and neoliberal modes of land control are central to state formation processes (Diepart & Dupuis, 2014).

A second body of knowledge examined the economics of boom crop production and the commercialization of smallholder agriculture. This literature argues that despite a quick increase in farm income and household assets in the early stages of the boom (Kem, 2017), agricultural expansion quickly made the farmers highly dependent on market fluctuations and generated negative impacts, including soil degradation and reductions in yield and crop profitability (Belfield, Martin, & Scott, 2013; Kong et al., 2016; Montgomery, Martin, Guppy, Wright, & Tighe, 2017).

However, the literature does not sufficiently capture the actual pathways of land use/cover change (LUCC) in the Northwest and in particular the institutions and mechanisms that are involved in the changes. To shed light on these processes, we have developed a multi-scale analysis that examines agrarian change over the past 40 years in the upland areas of Battambang and Pailin Provinces. This paper endeavors three things. Firstly, we set the magnitude of land cover changes at the landscape level (covering four districts) using remote sensing technologies. Secondly, by drawing on secondary data, we identify the proximate causes and underlying factors that have driven land cover changes. Thirdly, based on primary data collected during fieldwork conducted in 2016 and 2017 in one specific district of the study area, we develop a graphic representation of LUCC mechanisms that allow for a detailed understanding of the interactions between the multiple drivers of changes along with the variations of these interactions across time and space.