Economic Development and Land-Use Change: Expansion of Cash Crops in Southeast Asia


Expansion of rubber plantations in north-eastern Cambodia: Green tones are forest areas, beige to brown tones are annual crops, and orange to dark red tones are rubber plantations

Over the past half century, countries of South and Southeast Asia have witnessed a major shift from predominantly subsistence agriculture to industrialized economies. These changes have been accompanied by expanding urban populations and the growth of huge megacities around the region, often at the expense of prime farmland.

Commercialization of agriculture has also led to the expansion of cash crops, including several tree-based crops such as oil-palm, rubber, coffee, cashew, and fast-growing trees species for pulp and paper. In many areas, these have replaced foodcrops.

The mountainous region of mainland Southeast Asia is a large, ecologically important area that includes approximately one-half of the land area of Cambodia, Lao PDR, Myanmar, Thailand, Vietnam, and China's Yunnan Province. It is also a region of great biological and cultural diversity. This region has come under close scrutiny in the past several decades as a result of both real and perceived deforestation, land degradation, and most recently, the conversion from traditional agriculture, including shifting cultivation, to more permanent cash crops driven by regional and global markets. Rubber (Hevea brasiliensis) is the major commercial crop replacing traditional agriculture and secondary forests in the region, a direct result of strong market demand from China, the world's largest consumer.

In collaboration with colleagues in Asia and the United States, scholars at the East-West Center investigated the conversion of traditional mixed farming to rubber plantations in the mountainous area of mainland Southeast Asia. Using remotely sensed data, geographic information systems (GIS), and global positioning system (GPS) technology as well as surveys on the ground, research focused on the implications of this conversion for the wellbeing of local farmers and for water and carbon dynamics in the region.

Understanding the linkage between land-cover and land-use change and ecosystem carbon and water fluxes is challenging because both natural and human-induced processes are involved and and these occur over a wide range of spatial and temporal scales. This project involved a multidisciplinary team of foresters, geographers, and hydrologists from Thailand, Lao PDR, China, Vietnam, Cambodia, Myanmar, and the United States. The team sought to determine:

  • How do specific historical, socio-economic, and political factors in each country affect traditional farmers who make the transition to rubber cultivation?
  • What effect does the transition to rubber cultivation have on carbon emissions from the region?
  • Is it possible to design land-use strategies that will enhance development and food-security objectives while at the same time reducing carbon emissions?

Considerations for policymakers

Land-use policies in Thailand, Cambodia, Lao PDR, and southern China are leading to an increasingly homogenous landscape, dominated by rubber trees. Yet the impact of these policies on the food security and economic wellbeing of farmers could hardly be more different.

In parts of Thailand and China, the government has provided tree seedlings, secure land tenure, loans, and technical expertise to help local farmers take up rubber production and move out of poverty. In Cambodia and Lao PDR, in the absence of government oversight, foreign companies have initiated a variety of contractual arrangements with local farmers. Often, farmers have not benefited from the profits derived from rubber production. In some cases, they have even lost their land.

It is clear that policies that seek only to increase tree cover can have a range of impacts on smallholders’ livelihoods, varying from beneficial to destructive. And even the environmental effects are poorly understood. Little is known about rates of carbon cycling, either from traditional shifting cultivation or from rubber plantations. Given these uncertainties, it is risky to predict the environmental consequences of a change from one type of land use to the other.

It is, thus, perhaps impossible to suggest land-use policies that will ensure both a reduction in carbon emissions and an improvement in smallholder livelihoods. Nonetheless, emerging carbon-finance schemes are being developed across the tropics to provide economic incentives for more rural communities to transition away from shifting cultivation to other types of land use, including rubber.

Findings from the East-West Center project suggest that no “one-size-fits-all” policy is appropriate for the region as a whole. In some locations, standing forests exist that can be managed with a focus on protecting and improving carbon sequestration. In other locations, shifting cultivation may be the most rational land use for farmers from both economic and environmental perspectives. Policies should help farmers maintain or rehabilitate traditional farming systems, with fallow periods that are long enough to allow regeneration of mature secondary forests.

In still other locations, secondary forest fallows will be converted to permanent agriculture, largely dominated by tree crops such as rubber, coffee, and cashews. Policies should aim not only to increase carbon sequestration but also to improve the livelihoods of subsistence farmers and to protect other environmental services such as biodiversity and soil and water conservation. Such policies must provide economic support for small-scale, diversified, agroforestry systems, i.e., multi-storied agricultural systems that preserve the species diversity and ecological functions of a forest.

Collaborating scholars

Related publications

Ahrends, Antje, Peter M. Hollingsworth, Alan D. Ziegler, Jefferson M. Fox, Huafang Chen, Yufang Su, and Jianchu Xu (2015). Current trends of rubber plantation expansion may threaten biodiversity and livelihoods. Global Environmental Change 34:48-58.

Evans, Tom P., Khamla Phanvilay, Jefferson Fox, and John Vogler (2011). An agent-based model of agricultural innovation, land-cover change, and household inequality: The transition from swidden cultivation to rubber plantations in Laos PDR. Journal of Land Use Science 6(2-3): 151-73.

Fox, Jefferson (2014). Through the technology lens: The expansion of rubber and its implications in Montane Mainland Southeast Asia. Conservation and Society 12(4): 418-24.

Fox, Jefferson, and Jean-Christophe Castella (2013). Expansion of rubber (Hevea brasiliensis) in mainland Southeast Asia: What are the prospects for small holders? Journal of Peasant Studies 40(1): 155-70.

Fox, Jefferson, Jean-Christophe Castella, and Alan D. Ziegler (2014). Swidden, rubber, and carbon: Can REDD+ work for people and the environment in Montane Mainland Southeast Asia? Global Environmental Change 29:318-26.

Fox, Jefferson, Jean-Christophe Castella, and Alan D. Ziegler (2011). Swidden, rubber, and carbon: Can REDD+ work for people and the environment in Montane mainland Southeast Asia? CCAFS Working Paper 9. Copenhagen: CGIAR Research Program on Climate Change, Agriculture, and Food Security (CCAFS).

Fox, Jefferson, Jean-Christophe Castella, Alan D. Ziegler, and Sidney B. Westley (2014). Expansion of rubber mono-cropping and its implications for the resilience of ecosystems in the face of climate change in Montane Mainland Southeast Asia. Global Environmental Research 18(2): 145-50.

Fox, Jefferson, Jean-Christophe Castella, Alan D. Ziegler, and Sidney B. Westley (2014). Rubber plantations expand in mountainous Southeast Asia: What are the consequences for the environment? AsiaPacific Issues No. 114. Honolulu: East-West Center.

Fox, Jefferson, and John B. Vogler (2005). Land-use and land-cover change in Montane Mainland Southeast Asia. Environmental Management 36(3): 394-403.

Fox, Jefferson, John B. VoglerOmer L. Sen, Thomas W. Giambelluca, and Alan D. Ziegler (2012). Simulating land-cover change in Montane Mainland Southeast Asia. Environmental Management 49(5): 968-79.

Giambelluca, Thomas W., Ryan G. Mudd, Wen Liu, Alan D. Ziegler, Nakako Kobayashi, Tomo'omi Kumagai, Yoshiyuki Miyazawa, Tiva Khan Lim, Maoyi Huang, Jefferson Fox, Song Yin, Sophea Veasna Mak, Poonpipope Kasemsap (2016). Evapotranspiration of rubber (Hevea brasiliensis) cultivated at two plantation sites in Southeast Asia. Water Resources Journal. DOI: 10.1002/2015WR017755.

Guardiola-Claramonte, Maite, Peter A. Troch, Alan D. Ziegler, Thomas W. Giambelluca, Matej Durcik, John B. Vogler, and Michael A. Nullet (2010). Hydrologic effects of the expansion of rubber (Hevea brasiliensis) in a tropical catchment. Ecohydrology. 3(3): 306–14.

Guardiola-Claramonte, Maite, Peter A. Troch, Alan D. Ziegler, Thomas W. Giambelluca, John B. Vogler, and Michael A. Nullet (2008). Local hydrologic effects of introducing non-native vegetation in a tropical catchment. Ecohydrology 1(1): 13–22.

Kumagai, Tomo’omi, Ryan G. Mudd, Thomas W. Giambelluca, Nakako Kobayashi, Yoshiyuki Miyazawa, Tiva Khan Lim, Wen Liu, Maoyi Huang, Jefferson M. Fox, Alan D. Ziegler, Song Yin, Sophea Veasna Mak, and Poonpipope Kasemsap (2015). How do rubber (Hevea brasiliensis) plantations behave under seasonal water stress in northeastern Thailand and central Cambodia? Agricultural and Forest Meteorology 213:10-12.

Li, Zhe, and Jefferson Fox (2011). Integrating Mahalanobis typicalities with a neural network for rubber distribution mapping. Remote Sensing Letters 2(2): 157–66.

Li, Zhe, and Jefferson Fox (2011). Mapping rubber tree growth in mainland Southeast Asia using time-series MODIS 250 m NDVI and statistical data. Applied Geography 32(2): 420–32.

Sen, Omer L., Deniz Bozkurt, John B. Vogler, Jefferson Fox, Thomas W. Giambelluca, and Alan D. Ziegler (2013). Hydro-climatic effects of future land-cover/land-use change in montane mainland Southeast Asia. Climate Change. 118(2): 213–26.

Sturgeon, Janet C. (2010). Governing minorities and development in Xishuangbanna, China: Akha and Dai rubber farmers as entrepreneurs. Geoforum 41(2): 318-28.
Ziegler, Alan D., Shawn G. Benner, Chatchai Tantasirin, Spencer H. Wood, Ross A. Sutherland, Roy C. Sidle, Nicholas Jachowski, Mike A. Nullet, Lu Xi Xi, Anond Snidvongs, Thomas W. Giambelluca, Jefferson M. Fox (2014). Turbidity-based sediment monitoring in northern Thailand: Hysteresis, variability, and uncertainty. Journal of Hydrology 519:2020-39.

Ziegler, Alan D., Jefferson M. Fox, and Jianchu Xu (2009). The rubber juggernaut. Science 324(5930): 1024–25.

Related to staff: 

See all current East-West Center Research Projects.