Focal Area: Status and trends of the components of biodiversity

Headline Indictor: Trends in abundance and distribution of selected species

Key Indicator Partners:      

Data Available: Global time series, 1970 onwards

Development Status: Ready for global use

Wild species are under pressure across all biomes and regions of the world.  These declines ultimately result from humanity’s demands on the biosphere which result in habitat loss, over-exploitation, pollution, spread of invasive species and climate change.  Decline in species populations not only threatens biodiversity, but also ecosystem services which the human race depends on for a multitude of purposes including provision of food, medicine and basic materials.

The Living Planet Index (LPI) is calculated using time-series data on more than 7000 populations of over 2,300 species of mammal, bird, reptile, amphibian and fish from all around the globe. The changes in the population of each species are aggregated and shown as an index relative to 1970, which is given a value of 1. The LPI can be thought of as a biological analogue of a stock market index that tracks the value of a set of stocks and shares traded on an exchange.

The Global LPI is the aggregate of two equally-weighted indices of vertebrate populations - the temperate and the tropical LPIs – calculated as the geometric mean of the two. The tropical LPI consists of the terrestrial and freshwater species populations found in the Afrotropical, Indo-Pacific and Neotropical realms and marine species populations from the zone between the Tropics of Cancer and Capricorn. The temperate LPI includes all terrestrial and freshwater species populations from the Palearctic and Neartic realms, and marine species north and south of the tropics. In the tropical and temperate LPIs the overall trends in terrestrial, freshwater and marine species are given equal weight. The results of the LPI are published biennially in the Living Planet Report.

The LPI is not only a global index but can also be calculated for selected regions, nations, biomes or taxonomic groups, provided that there are sufficient data available.

Global Living Planet Index (1970-2005)
Source: WWF & ZSL

A decrease in the LPI represents an overall reduction of species populations, meaning more species have declined than increased in abundance. This implies that diversity will have reduced, even if none of those species populations has declined to zero (extinction).

A constant LPI represents no overall change in species populations and would imply no overall biodiversity loss.

‘The current global LPI shows a 30% decline from 1970 to 2005 meaning that on average, vertebrate populations have declined in abundance over this 35 year period. The temperate and tropical indices show contrasting results. The tropical index shows that vertebrate populations have declined markedly (about 60%) since 1970 whereas temperate populations have increased by an average of 18%. Although the tropical index reveals a worse trend than the temperate index, it does not necessarily imply that tropical biodiversity is in a worse state as temperate populations may have undergone similar declines before 1970 when pressures were already high in many temperate regions.’

The LPI is not only a global index but can also be calculated for regions and nations provided that there are sufficient data available.

The present aim is to increase the species population data coverage of the LPI in tropical regions, where there are more species but fewer data than in temperate regions, and for less well represented vertebrate groups (amphibians, reptiles, fishes). The LPI database will be made accessible via the worldwide web.