Forests

The Living Planet Index - Forest Ecosystem Index

How fast is nature disappearing from the Earth?

The Living Planet Index (LPI) is an indicator of the overall state of the Earth's natural ecosystems, which includes national and global data on human pressures on natural ecosystems arising from the consumption of natural resources and the effects of pollution. The 1999 LPI primarily measures abundance and is derived from an aggregate of three different indicators of the state of natural ecosystems, being:

1). the area of the world's natural forest cover,
2). populations of freshwater species around the world, and
3). populations of marine species around the world.

Each of these individual component indices is set at 100 in 1970, and are given an equal weighting. The overall LPI has declined by 30% between 1970 to 1995, implying that the world has lost 30% of its natural wealth in the space of a generation.

The Forest Ecosystem Index is based on the change in natural forest cover (i.e. excluding plantations) worldwide. Natural forest cover has been declining steadily since the 1960's, and from 1970 to 1995 about 10% of the total cover was lost. This amounts to a change in cover from about 35 million square kilometres (km2) to 32 million km2 or a decrease of about 0.5% per year. It must be realised that this decline in cover probably masks a steeper, but unquantified, loss of biodiversity and forest quality, particularly in temperate forests. See the Forest Ecosystem Index below:





Forest Ecosystem Index, set at 100 in 1970, shown on a five yearly basis, with upper and lower confidence limits shown (within the 95% confidence interval).

Source of text, adapted from:
WWF International (1999) Living Planet Report 1999.