The world's forests continue to shrink as populations increase and forest land is converted to agriculture and other uses, but over the past 25 years the rate of net global deforestation has slowed down by more than 50%, the Food and Agriculture Organisation (FAO) of the United Nations said in a report published Monday.

Some 129m hectares of forest - an area almost equivalent in size to South Africa - have been lost since 1990, according to FAO's most comprehensive forest review to date, The Global Forest Resources Assessment 2015.

It noted however, that an increasing amount of forest areas have come under protection while more countries are improving forest management. This is often done through legislation and includes the measuring and monitoring of forest resources and a greater involvement of local communities in planning and in developing policies.

The FAO study covers 234 countries and territories and was presented at this week's World Forestry Congress in Durban, South Africa.

"Forests play a fundamental role in combating rural poverty, ensuring food security and providing people with livelihoods. And they deliver vital environmental services such as clean air and water, the conservation of biodiversity and combating climate change," said José Graziano da Silva, FAO director-general, launching the report in Durban.

He noted an "encouraging tendency towards a reduction in rates of deforestation and carbon emissions from forests," as well as improved information that can inform good policy, noting that presently national forest inventories cover 81% of global forest area, a substantial increase over the past 10 years.

Main findings

While in 1990 forests made up 31.6% of the word's land areas, or some 4,128m hectares, this has changed to 30.6% in 2015, or some 3,999m hectares, according to FRA.

Meanwhile, the net annual rate of forest loss has slowed from 0.18% in the early 1990s to 0.08% during the period 2010-2015.

Today, the bulk (93%) of the world's forest area is natural forest — a category that includes primary forest areas where human disturbances have been minimized, as well as secondary forest areas that have regenerated naturally.

Planted forest, another subcategory, currently accounts for 7% of the world's overall forest area, having increased by over 110m hectares since 1990.

FAO's report stresses the critical importance of forests to people, the environment, and the global economy.

The forest sector contributes about $600 billion annually to global GDP and provides employment to over 50m people.

Biggest losses in Africa and South America

Africa and South America had the highest net annual loss of forests in 2010-2015, with 2.8 and 2m hectares respectively, but the report notes how the rate of loss has "substantially decreased" from the previous five year period.

Since 1990 most deforestation has taken place in the tropics. In contrast, net forest area has increased in temperate countries while there has been relatively little change in the boreal and subtropical regions.

However, given global population growth, average per capita forest area has predominantly declined per person in the tropics and subtropics, but also in all the other climatic regions with the exception of the temperate.

Better-managed forests

The report says globally, natural forest area is decreasing and planted forest area is increasing and while most forests remain publicly owned, ownership by individuals and communities has increased. In all cases FAO stresses the importance of sustainable forest management practices.

Natural forests, the least touched by humankind, contribute to conserving genotypes — the genetic constitutions of organisms —and in maintaining the composition of natural tree species while providing vital habitats to endangered animal species.

Forests help replenish groundwater supplies crucial for drinking, agriculture and other uses. They also protect soils from erosion, avalanches and landslides.

Planted forests, for their part, are often established for production and where well-managed can provide various forest goods and service and help reduce the pressure on natural forests.

This must also be seen in the context of the increase in global wood consumption and the continued widespread reliance on woodfuel.

"The management of forests has improved dramatically over the last 25 years. This includes planning, knowledge sharing, legislation, policies - a whole range of important steps that countries have implemented or are implementing," said Kenneth MacDicken, leader of FAO's Global Forest Resources Assessment Team.

He underscored how since 1990 the designation of additional forest land for conservation increased by some 150m ha and that forest in protected areas has increased by over 200m hectares.

Safeguarding biodiversity

The FAO says forests are rich in biologically diversity, and home to more than half of the terrestrial species of animals, plants and insects. The agency warns that despite conservation efforts the threat of biodiversity loss persists and is likely to continue with deforestation, forest degradation - a reduction in tree biomass density from human or natural causes such as logging, fire, windthrows and other events - pollution and climate change all having negative impacts.

Currently, forest area primarily designated for biodiversity conservation accounts for 13% of the world's forest, or 524m hectares, with the largest areas reported in Brazil and the United States.

Over the last five year period Africa reported the highest annual increase in the area of forest for conservation while Europe, North and Central American and North America reported the lowest compared to previous reporting periods, while the increase reported by Asia for 2010-2015 was lower than that reported for 2000-1010 but higher than the increase reported in the 1990s.

Addressing climate change

Deforestation and forest degradation increase the concentration of greenhouse gases in the atmosphere, but forest and tree growth absorbs carbon dioxide which is the main greenhouse gas. FAO notes how a more sustainable management of forests will result in a reduction in carbon emissions from forests and has a vital role to play in addressing the impacts of climate change.

FAO has estimated that total carbon emissions from forests decreased by more than 25% between 2001 and 2015, mainly due to a slowdown in global deforestation rates.

Pic above courtesy of the World Wildlife Fund (WWF), depicting the rain forest in Sabah, a state of Malaysia, on the island of Borneo.