Growing cities and crops means the forests fall

15.02.10

A new report in Nature Geoscience that studied high-resolution satellite imagery from 41 countries shows that deforestation is being driven by urban population growth and agricultural trade in the 21st century.

This may not sound like news to many, but it's one of the first times we have seen documented evidence that the emptying of rural areas is contributing to deforestation. It's previously been widely assumed that increasing urbanisation and modern ultra-efficient mass agriculture may contribute to a slowing of global deforestation rates.

Forest being burnt for agriculture

This settler in the Mau Forest, Kenya is clearing land for subsistence agriculture, which was previously thought to be one of the main factors contributing to deforestation. The new study shows that the most important causes of deforestation in the 21st century are probably an expanding urban population and global agricultural trade. © Christian Lambrechts, UNEP

This assumption came on the back of studies in the late 20th century that showed rural growth was the cause of much deforestation. As the forests were opened up by roads and other infrastructure so people could move in to previously inaccessible landscapes to practice subsistence agriculture.

But 2009 marked a remarkable turning point in the history of mankind. It was the first year on record where an equal number of the human population lived in urban and rural areas. And this swinging trend in the way we live seems to have set in as the report states "population growth rates are slowing overall, but urban growth is vastly outpacing rural growth."

The research team aimed to identify the factors most closely related to tropical forest loss, rather than predict forest loss per se. By studying 10 possible factors - four related to agricultural production, four demographic factors, and two economic factors - and correlating them it was possible to see which may prove to have the biggest impact on the humid tropic biome.

Both the research methods, linear regression and regression tree, show a positive relationship between urban growth, agricultural exports, and forest loss. The most significant factors associated with satellite-derived forest loss are urban growth rate and net agricultural trade per capita. The researchers are keen to stress this does not necessarily indicate "causality", but the "positive correlations do suggest that the traditional mode of clearing in frontier landscapes for small-scale production to support subsistence needs or local markets is no longer the dominant driver of deforestation in many places."

The challenges facing tropical forests, as more and more people try and get more and more out of them, are unrelenting. They are also now embroiled in the political climate football, REDD. The ambition of REDD is to value and maintain standing forests, but this relies on agricultural production being displaced somewhere else.

Tough questions will face the rainforest conservation community and how best to marry the opportunities of relatively small-scale community led conservation while maximising yields on already converted land to avoid more mass clearance of forest.

Full report in Nature Geoscience

Related links:

UK: World Land Trust bring conservation to Chelsea

04.02.10

atlantic forest by dan ryanThe World Land Trust (WLT) are taking a conservation message to the world's most famous horticultural event, the RHS Chelsea Flower Show.

Philippines: Geo-tagging reveals mining threats on the “Last frontier”

01.02.10

mining in the philippinesPlant Talk invited Dario Novellino from the Centre for Biocultural Diversity (CBCD), UK to speak out against the logging and mining in protected areas that is destroying the forests of Palawan.

Ecuador: Yasuni - the most biodiverse place on Earth?

22.01.10

Ecuador thumbA study published in the open access journal Plos One has revealed extraordinary species richness in the western Amazon covering eastern Ecuador and northern Peru.

Madagascar IN PICTURES

19.01.10

madagascar thumbGreg Farrington, Executive Director of the California Academy of Sciences, recently visited the vast island of Madagascar with some of his team of researchers. He was kind enough to share some of his beautiful images of the extraordinary landscapes, plants, and people (and in a break from tradition, some animals too!) with Plant Talk.

Copenhagen: Nature has the solutions

07.12.09

rainforest thumbnailOn the opening days of the Copenhagen Climate Conference there has been a call from IUCN urging leaders meeting in Copenhagen to include nature’s solutions to reduce emissions and cope with impacts of climate change in a post-2012 deal.

Amazon: Deforestation rate drops

24.11.09

what are forests worth?Deforestation in the Amazon is at its lowest rate for 20 years according to the latest data from the Brazilian government. Only - and it is a painful only - 7,000 square kilometres of forest was destroyed or damaged in the year August 2008 to July 2009.

Guyana: Norway pledge investment in forests

12.11.09

rainforestThe government of Norway has pledged up to $250 million in the protection of Guyana's forests. The agreement will ensure an initial payment of $30 million into the countries REDD+ fund and the rest will come if this investment succeeds in reducing emissions and tackling poverty.