About 97 per cent of the world’s natural rubber is produced in South-East Asia where production increased to more than five million tonnes in 2011 from 300,000 tonnes in 1961, says a study published online this month in the journal Global Environmental Change.
But the region only has 1.5 per cent of environmental space, or 260,000 square kilometres of the 16 million square kilometres globally that are estimated to be suited for rubber cultivation, notes the study which used climatic models to measure growth in global rubber cultivation.
The study defines continental South-East Asia as comprising Cambodia, China, Laos, Myanmar, Thailand and Vietnam.
Many of the new rubber plantations that appeared between 2005 and 2010 are monocultures in “increasingly sub-optimal” environments like steep hillsides or cleared forest land.
Global rubber prices soared in 2001-2011 but growing rubber on marginal lands may eventually create “lose-lose scenarios” in which the environment is damaged and farmers’ livelihoods are threatened, the study says.
“Although rubber at current price levels produces lucrative yields in many marginal areas and there is frequently a lack of better alternative crops, policy interventions and greater awareness are needed given that rubber prices are volatile and cash crops such as rubber are currently the main drivers of forest loss in continental South-East Asia,” the study stresses.
The new rubber plantations are more susceptible to erosion and increase the need for agro-chemicals that pose risks to surface and groundwater quality. In 2013, typhoons destroyed rubber plantations worth US$250 million in Vietnam.
The study says there is an “urgent need” for systematic monitoring of how the expansion of rubber in marginal environments has affected ecosystem services.
But one of the study’s authors, Jianchu Xu of the Kunming Institute of Botany in China, tells SciDev.Net that such monitoring will be difficult to implement because environmental issues do not yet top the agenda for regional collaboration.
“It is not due to lack of money for environmental monitoring,” he says by email.
Junzuo Zhang, team leader at the China-UK Collaboration on International Forest Investment & Trade in Beijing, tells SciDev.Net that the new rubber study “will make a good contribution to current research in this field”. She did not elaborate.
She says the China-UK venture would soon develop a guide for Chinese companies that invest overseas. The guide will require reductions in the impacts that China’s international trade in timber and other forest commodities produce and also promote “environmentally and socially sound resource management practices in developing countries”.
>Link to full paper in Global Environmental Change
This article has been produced by SciDev.Net's South-East Asia & Pacific desk.