Living Planet Index
About the index
The Living Planet Index (LPI) is a measure of the state of global biological diversity based on population trends of vertebrate species from around the world. It does this in much the same way that a stock market index tracks the value of a set of shares or a retail price index tracks the cost of a basket of consumer goods.
The Living Planet Database (LPD) currently holds time-series data for over 20,000 populations of more than 4,200 mammal, bird, fish, reptile and amphibian species from around the world, which are gathered from a variety of sources such as journals, online databases and government reports. Using a method developed by ZSL and WWF, these species population trends are aggregated to produce indices of the state of biodiversity. The rest of our work focusses on expanding the coverage of LPI data to more broadly represent vertebrate biodiversity from all around the globe and disaggregating the index to measure trends in different thematic areas. This includes assessing the changes in different taxonomic groups, looking at species trends at a national or regional level, identifying how different threats affect populations and providing an insight into how conservation intervention can promote species recoveries.
The LPI played a pivotal role in measuring progress towards the 2010 target of the Convention on Biological Diversity (CBD) to reduce the rate of biodiversity loss which, according to the suite of 2010 biodiversity indicators, was not met.
In response, the 193 nations of the CBD committed themselves to a revised Strategic Plan for Biodiversity, including the Aichi Biodiversity Targets , for the 2011-2020 period including actions which will “…take effective and urgent action to halt the loss of biodiversity in order to ensure that by 2020 ecosystems are resilient and continue to provide essential services, thereby securing the planets variety of life, and contributing to human well-being, and poverty eradication”.
The 2020 targets focus on maintaining ecosystem services in which biodiversity plays an important role. The Living Planet Index is an applicable indicator for many of the Aichi Biodiversity targets under Strategic Goals A-D which address the causes, pressures, state and benefits of biodiversity.
Calculating the index
To calculate an LPI, a generalised additive modelling framework is used to determine the underlying trend in each population time-series (Collen et al. 2009; Loh et al. 2005). Average rates of change are then calculated and aggregated to the species level. For the global LPI, the method of aggregation has recently been revised to include a weighting system which gives trends from more species-rich systems, realms and groups more weight in the final index (McRae et al. 2017).
The global trend
The global LPI as presented in the Living Planet Report 2018 (Figure 1) shows that a subset of 16,704 populations of 4,005 species has declined by 60% in abundance between 1970 and 2014. The Living Planet Report 2018 results indicate that species are faring much worse in freshwater systems and in tropical realms. Freshwater populations declined by an average of 83%, while realms - large regions separated by major barriers to plant and animal migration and therefore characterized by distinct assemblages of species - declined by between 23% and 89%, with the Neotropical and Indo-Pacific realms showing the steepest declines (89% and 64%, respectively).
Figure 1: The global LPI shows a 60% decline between 1970 and 2014. The white line shows the index values and the shaded areas represent the 95% confidence limits surrounding the trend (WWF/ZSL 2018)
The population time-series data in the LPI are augmented with additional information relating to the population’s taxonomy, location and ecology, which allows for the analysis of trends at different scales and for different habitats. This is how the global trend shown above can be subdivided to show trends in temperate and tropical regions and different systems or biogeographic realms.
In addition, subsets of populations of the LPI can:
- provide a basis for tracking progress with respect to multi-lateral agreements such as the Convention for the Conservation of Migratory Species
- be used to create an index of biodiversity trends in a particular country such as Canada
- be used for exploring trends in selected groups of species such as utilised species or specific taxonomic groups
- and for producing regional and global indices representing particular habitats or biomes.
Our projects page gives more information about how the LPI has been used.