Forest degradation

Significant deforestation is caused by forest degradation, a gradual destructive process. Climate change, forest fires and illegal logging are driving this kind of deforestation.

Erosion craters caused by deforestation
© Martina Lippuner / WWF


Key Facts

  • Around 1% of forests is significantly affected each year by forest fires, although the area of forest affected by fires is severely underreported.
  • Less than 10% of all forest fires are prescribed burning, the rest are classified as wildfires.
  • Outbreaks of forest insects pests damage some 35 million hectares of forest each year.

Forest Fires

Each year, fires burn millions of hectares of forest worldwide. The resulting loss and degradation of forested land is roughly equal to that caused by destructive logging and conversion to agriculture combined, and has wide-reaching consequences on biodiversity, health and the economy.
Forest fires are a natural part of ecosystems in many forest types, particularly in boreal and dry tropical forests where they are a frequent and expected feature.

When forest fires become a problem…

Fires become a problem when they burn in the wrong places, or at the wrong frequency or the wrong temperatures. Globally, most forest fires are probably now directly or indirectly influenced by humans.

Fire is often used to 'manage' forests because it is cheap, simple to apply and sometimes because it is the only option available for poorer people and smallholders.

Effects of forest fires

Fires can alter the structure and composition of forests, opening up areas to invasion by fast-colonizing alien species and threatening biological diversity.
  • Buildings, crops and plantations are destroyed and lives can be lost.
  • For companies, fire can mean the destruction of assets.
  • For communities, besides loss of an important resource base, fire can also lead to environmental degradation through impacts on water cycles, soil fertility and biodiversity.
  • For farmers, fire may mean the loss of crops or even livelihoods.
This helicopter fighting fires in the Lozère can download only 500 liters of water per flight. ... / ©: WWF / Michel GUNTHER
Forest fire in southern France, 2003
© WWF / Michel GUNTHER

Climate Change

From rainforests to montane forests, and savannas to boreal forests, these ecosystems are undergoing transformations as a result of climate change.
The effects of climate change include increasing mean and peak temperatures, growing number and intensity of droughts, affecting forests around the world and the wildlife and humans that depend upon them, and increased frequency of extreme weather events.

Research shows that climate change makes forests drier, suggesting that it is more likely forest fires will increase in number and severity due to increases in temperature and lower humidity.

Future  El Niño events - the periodic  upwellings of warm waters in the Pacific Ocean which affect weather patterns across the globe - could increase incidences of fire, particularly in the forests of South America, releasing millions of tonnes of stored carbon dioxide into the atmosphere.

Impacts of climate change on forest wildlife

Forest wildlife is most likely to be affected through the change of habitat and the lack of water. As average temperature increases, optimum habitat for many species will move to higher elevations or higher latitudes.

Where there is no higher ground or where changes are taking place too quickly for ecosystems and species to adjust, local losses or global extinctions will occur. Changes can also allow invasive species to flourish, threatening the habitat of endemic species.
 / ©: WWF / Mauri Rautkari
The combination of climate change and deforestation increases the drying effect of dead trees that fuels forests fires.
© WWF / Mauri Rautkari

Did you know?

    • Wildfires occur on every continent except Antartica.
    • The mountain pine beetle has devastated more than 11 million hectares of forest in Canada and western United States since the late 1990s, partly due to higher winter temperatures.

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