A new technique for measuring the state of the world’s forests shows the future may not be as bad as previously feared.
An international team of researchers say its Forest Identity study suggests the world could be approaching a “turning point” from deforestation.
The study measures timber volumes, biomass and captured carbon - not just land areas covered by trees.
The findings are being published in the US journal Proceedings of the National Academy of Sciences.
“The trend is better than previously thought,” said Pekka Kauppi, one of the paper’s co-authors.
“We see prospects for an end to deforestation; we do not make a forecast but it is possible.”
Professor Kauppi, from the University of Helsinki, said data from the Forest Identity methodology offered a more sophisticated view than previous studies.
“Previously, the focus was almost exclusively on the size of a forest area,” he told BBC News. “Now, we have included other components, including biomass and the amount of carbon stored.”
He said this approach offered a better understanding of the natural resource: “When we look at changes in both area covered and biomass, we can get a more complete picture of the ecosystems.”
When the technique was applied to data from the UN Food and Agriculture Organisation’s (FAO) Global Forest Assessment report, the researchers found that forest stocks had actually expanded over the past 15 years in 22 of the world’s 50 most forested nations.
They also showed increases in biomass and carbon storage capacity in about half of the 50 countries.
But the data also revealed that forest area and biomass was still in decline in Brazil and Indonesia, home to some of the world’s most important rainforests.
Demand for land
The report also showed a correlation between a nation’s economic growth and “forest transition”, in other words, a shift from deforestation to net gains in tree cover.
The researchers found that when Gross Domestic Product (GDP) per capita reached $4,600 (£2,400), many nations experienced forest transition and saw an increase in forestry growing stock (volume of useable timber).
Professor Kauppi said no nation intentionally destroyed forests, people did it out of necessity.
“Rural populations, which are poor and growing, have to convert new land to agriculture and subsistence farming,” he observed.
“So the pressures on the forests ease if people have other job sources. We are not saying that people, because they are wealthier, do not destroy forests but it is a sign that societies have good law enforcement and rural policies.”
But there was a risk that a misleading picture was being created by rich nations importing raw timber or wood-based products from poorer nations, rather than destroying their own woodlands.
“This is a serious problem,” Professor Kauppi said. “It is called ‘leakage’ or ‘exporting ecological impacts’ and it exists, unfortunately.”
But he emphasised that, overall, international trade was not bad: “If agricultural production takes place in highly productive regions, then land elsewhere can be protected or saved.”
He hoped the Forest Identity formula would be used as a tool to help governments and policymakers to formulate effective strategies.
"For example, you can set goals by analysing the changes in forest area and forest density and then make projections of alternative futures.
“You cannot change things overnight. Making promises and goals that are unrealistic is bad; you have to set demanding, yet achievable aims.”
Professor Kauppi said he was hopeful for the long-term future of the planet’s forests, but warned that appropriate action was essential.
“Critically, it is about how people live in rural areas in developing nations,” he concluded. “Can their living conditions be improved? If they can, then there is reason to be optimistic.”