AfterTek

The forests are increasing in countries across the world after centuries of being destroyed for their wood and to make way for people, according to research. By measuring the density of trees rather than simply the area on which they grow, scientists have calculated that forests are increasing in almost half of the world’s 50 most wooded nations.

Forests are still diminishing in some countries, such as Brazil and Indonesia. In others, such as China, they are now expanding, although world stocks are still about 2.5 per cent lower now than in 1990. Stocks of trees increased most rapidly in Spain and Ukraine, and were lost most quickly in Indonesia, Nigeria and the Philippines between 1990 and last year. The area covered by trees increased most quickly in Vietnam, Spain and China, and reduced most quickly in Nigeria and the Philippines, according to the study.

The greatest total gain of the number of trees and the area of forest was made in China and the US. Indonesia and Brazil lost the most, while in India forest coverage is now stable. The researchers, whose study is published in the journal Proceedings of the National Academy of Sciences, said the findings offered hope that forestry loss worldwide would be reversed within a few years.

“An increasing number of countries and regions are from deforestation, raising hopes for a turning point for the world as a whole,” they said. “Amid widespread concerns about deforestation, growing stock has in fact expanded over the past 15 years in 22 of the world’s 50 countries with the most forest.

An increasing number of countries show gains.”  The study was carried out by six academics and non-governmental forestry experts, including Alexander Mather, of the University of Aberdeen.

The improvements in tree density are thought by the team to be the result of better forest management and advances in agriculture, which have enabled farmers to produce more food per acre, thereby reducing their need to encroach on wooded areas.

“This great reversal in land use could stop the styling of a ‘Skinhead Earth’ and begin a great restoration of the landscape by 2050, expanding the global forest by 10 per cent about 300 million hectares, the area of India,” said Jesse Ausubel, the director of the programme for the human environment at Rockefeller University in New York.

Pekka Kauppi, of the University of Helsinki, said: “Without depopulation or impoverishment, increasing numbers of countries are experiencing transitions in forest area and density. While complacency would be misplaced, our insights provide grounds for optimism about the prospects for returning forests.” Data from before the middle of the last century are at best sketchy, but where available they appear to support Dr Kauppi’s hypothesis.

French forestry records dating back to the Middle Ages show an arboreal renaissance, apparently unaffected by population increases. By 1800 forest cover in France had fallen to less than one third of the level three centuries before. After industrialisation, however, the trend suddenly reversed.

Forest cover has risen steadily since. Dr Kauppi explained: “The main obstacles to forest transition are fast-growing, poor populations who burn wood to cook, sell it for quick cash, and clear forest for crops.