Assessing the capacity of ecosystems to retain biological diversity under climate change

A wide range of indicators has been developed to track progress towards achieving the 20 Aichi Biodiversity Targets adopted in 2010 by the Conference of the Parties (COP) of the Convention on Biological Diversity (CBD). Target 15 on ecosystem resilience and degradation, however, was poorly served by existing indicators.

In this paper, researchers from Australia introduce the Bioclimatic Ecosystem Resilience Index (BERI), tailored specifically to assess change in the capacity of ecosystems to retain biological diversity under climate change, thus addressing a key aspect of Aichi Target 15.

Occupying the middle ground between modelling of shifts in species distributions and analyses based on spatiotemporal patterns in climate alone, BERI is calculated based on input from three sources: 1) compositional-turnover models derived from species occurrences of all all terrestrial species (including GBIF-mediated data for vascular plants, reptiles and insects) combined with climate and environmental data, 2) scenarios of plausible future climates, and 3) data on observed changes in habitat condition resulting from ecosystem degradation, conservation and restoration.

As an example, the authors apply the approach to calculate and assess changes in BERI to a single forest biome (tropical and subtropical moist broadleaf forests) using turnover models for all vascular plants and habitat conditions for four different years.

The results show that in general, larger expanses of intact forest have higher BERI values, suggesting that overall levels of habitat loss and fragmentation are key determinants of the capacity of ecosystems to retain biodiversity under climate change. Projected changes in certain climate variables, however, also play an important role as some otherwise intact areas, such as parts of the Amazon, exhibited much lower BERI values than expected, potentially due to future reduction in precipitation.