The new land-use tsunami imperiling the tropics

Oil palm, oil palm, oil palm.  For years we've heard that a tidal wave of oil palm expansion is one of the biggest and fastest-growing threats to the world's rainforests.

But there's a new peril in town: rubber.  And it's also spreading like a destructive tsunami.

Spreading like wildfire

Two recent papers -- by Eleanor Warren-Thomas and colleagues and by Antje Ahrends and colleagues -- have underscored just how desperate the situation is becoming, especially in Southeast Asia.

As a result of escalating demand for natural rubber, plantations are increasingly gobbling up large expanses of land in Southeast Asia and the Asian mainland, as well as tropical Africa and Latin America. 

For instance, vast expanses of native forests have been cleared for rubber plantations in southern China,  which sustains many of that nation's biologically richest ecosystems. 

The current global production of rubber (from Warren-Thomas et al. 2015)

Warren-Thomas et al. see a rapidly worsening situation.  To meet expected demand, they estimate that from 4.3 to 8.5 million hectares of new rubber plantations -- an area up to three times the size of Belgium -- will be needed by 2024, threatening in particular significant areas of Asian forest, including many protected areas.

Expect especially rapid increases in rubber plantations in Laos, Cambodia, Vietnam, Thailand, Myanmar, Malaysia, and Indonesia, say the authors.

Ahrends and colleagues emphasize that rubber is now expanding into many areas that are ecologically marginal for rubber production.  In Southeast Asia, they estimate that 57% of the rubber plantations are currently vulnerable to droughts, erosion, frost, or wind damage.

Rubber is now spreading into marginal areas beset by high risks (from Ahrends et al. 2015)

In 2013, for instance, typhoons in Vietnam alone destroyed over $US250 million in rubber plantations.  And future climate change could make conditions across Southeast Asia even worse for rubber, they contend.

The worst news of all is that native forests and other habitats are often being cleared for rubber production.  For example, say Ahrends et al., between 2005 and 2010, over 250,000 hectares of natural tree cover and 61,000 square kilometers of protected areas were converted to plantations in tropical and subtropical Asia.

This is scary news for the environment, for it suggests that a 'second tsunami' of forest-destroying plantations for rubber could soon follow just on the heels of the explosive expansion of oil palm.