The global demand for rubber tyres is threatening protected forests in Southeast Asia, according to a study.

Tropical forests are being cleared for rubber plantations, putting endangered birds, bats and primates at risk, say UK researchers.

By 2024, up to 8.5 million hectares of new rubber plantations will be needed to meet demand, they report in Conservation Letters.

This could have a "catastrophic" impact on wildlife, they warn.

Species such as the endangered white-shouldered ibis, yellow-cheeked crested gibbon and clouded leopard could lose precious habitat, said the team led by Eleanor Warren-Thomas, from the School of Environmental Sciences at the University of East Anglia.

"The tyre industry consumes 70% of all natural rubber grown, and rising demand for vehicle and aeroplane tyres is behind the recent expansion of plantations. But the impact of this is a loss of tropical biodiversity," she said.

"We predict that between 4.3 and 8.5 million hectares of new plantations will be required to meet projected demand by 2024. This will threaten significant areas of Asian forest, including many protected areas."

Eight-point-five million hectares is about the size of the land area of Austria.

Biodiversity concern

Rubber is the most rapidly expanding tree crop within mainland Southeast Asia.

Concern has been growing among conservationists that switching land use to rubber cultivation can harm soil, water and biodiversity.

The first review of the effects on biodiversity and endangered species found the problem was comparable to oil palm and was linked to the growing tyre market.

The study focused on four biodiversity hotspots in which rubber plantations are expanding:

          - Sundaland (Malay Peninsula, Borneo, Sumatra, Java, and Bali)

          - Indo-Burma (Laos, Cambodia, Vietnam, most of Myanmar and Thailand, and parts of Southwest China, including Xishuangbanna and Hainan Island)

          - Wallacea (Indonesian islands east of Bali and Borneo but west of New Guinea, plus Timor Leste)

          - The Philippines.

It found that numbers of bird, bat and beetle species can decline by up to 75% in forests that have been converted to rubber.

Sustainability initiatives

The researchers, from UEA and the University of Sheffield, are calling on tyre manufacturers to support initiatives such as certification schemes.

Commenting on the study, Dr Matthew Struebig of the Durrell Institute of Conservation and Ecology, University of Kent, UK, said certification standards for the rubber industry were key to protecting forests.

"There's a lot we can do as scientists and the public to make rubber production more wildlife-friendly," he said.

"It can range from agro-forestry - mixing rubber with other trees - to retaining patches of natural vegetation along rivers or in small conservation set-asides, as is done in organic farming in Europe.

"The onus is on the rubber industry to develop a certification standard that is credible, for the public to support that, and for scientists to help develop ways to manage the rubber crop in an environmentally friendly way."