Deforestation and forest degradation a major threat to global biodiversity

The 2020 edition of The State of the World's Forests (SOFO), published last week, calls for urgent action to safeguard the biodiversity of the world's forests amid alarming rates of deforestation and degradation.

According to the report - produced by the FAO and UNEP, with technical input from the JRC - global forest area decreased from 32.5% to 30.8%, and some 420 million hectares of forest have been lost to agriculture and other land uses since 1990.

This continued degradation of forests threatens biodiversity and the survival of many species, and exacerbates global warming.

Intact forests are key for global biodiversity

As forests harbour most land-based plant and animal species, safeguarding woodland holds the key to protecting global biodiversity.

The SOFO report shows that forests contain 60,000 different tree species, 80% of amphibian species, 75% of bird species, and 68% of the Earth’s mammal species.

Their well-being and survival depend on the quality and intactness of the forest habitat.

It is therefore important to monitor the status and trends of forest patches, their integrity and how well they are connected.

JRC report on global forest fragmentation

Forest fragmentation – the division of continuous habitat into smaller and more isolated fragments – represents a serious threat to the integrity of ecosystems and biodiversity.

It can lead to the isolation and loss of species and gene pools, degraded habitat quality, and a reduction in the forest’s ability to sustain the natural processes necessary to maintain ecosystem health.

At the request of the FAO, the JRC carried out a global spatial analysis to identify those forests that are the most intact and connected and those where fragmentation is most severe.

This analysis, reported in chapter 2 of the SOFO report, highlights the urgent need to reconnect forests that have fragmented over time.

Using the Copernicus Global Land Cover map, delineated into 20 Global Ecological Zones, the JRC study found 34.8 million patches of forest in the world, ranging in size from 1 hectare to 680 million hectares.

As most of the world's forest area is concentrated in very few locations, the 149 biggest patches account for more than 80% of the global forest area.

The rest of the world’s forests are scattered and comparatively small.

The average size of all forest patches is a mere 132 hectares, but this varies significantly between ecological zones.

The largest average patch sizes are found in the boreal coniferous forest and tropical rainforest zones.

The methodology used to analyse the data is described in a JRC Technical Report on forest fragmentation.

Need to reverse human pressures and expand protected areas

The SOFO report calls for transformational change in food production and consumption, an integrated landscape approach to conserving and managing forests and trees, and greater coordination of efforts to restore forests.

In recent decades, human activities have caused deforestation, landscape fragmentation, global warming and greater frequency of natural hazards.

This exploitation of nature comes at significant environmental, social and economic cost. For example, in the EU alone, forest fires account for an annual economic loss of 2 billion euro.

Forest fragmentation, one of the effects of the ever-increasing pressure from anthropogenic land use, has been established as a Sustainable Development Goal (SDG) indicator for SDG 15 “Life on Land”, to help locate and measure various degrees of forest fragmentation at global scale.

Monitoring the intactness of and connectivity between (protected) forest areas is therefore crucial for sustainable development, particularly in the context of the European Green Deal.

Further information