A Benchmark for Biodiversity Quality: The Indicator Species Score

A new article in the journal Ecological Indicators highlights the Indicator Species Score (ISS), a new metric for tracking biodiversity quality.

Biodiversity quality is high if a large number of the native species that were historically common and well-distributed in the region remain so. If many previously common and well-distributed species are absent or reduced in distribution, biodiversity quality has declined. If the species most affected are already identified to be of conservation concern then biodiversity quality has declined more than if this is not the case.

The development of the ISS as a biodiversity quality index is the latest in a series of technical methods in landscape ecology and monitoring to come out of TRCA’s Environmental Monitoring and Data Management (EMDM) team.

graphic summarizing terrestrial biodiversity article

The ISS is unique in that it incorporates the Species of Conservation Concern scores for the species monitored into the evaluation of monitoring results.

This means that species of higher conservation concern contribute more to site scores, where found, than do species not considered of concern. The method is designed to support conservation management decision-making by providing benchmarks against which the success of conservation actions of various kinds can be measured.

The article assesses the practical value of the ISS by applying it to 10 years of EMDM terrestrial species monitoring data. Comparisons highlight the large differences in average scores between the urban and rural zones of the Toronto region.

The ISS demonstrates the relationship between biodiversity quality and habitat area, and documents the impact that urban cover has on biodiversity quality in adjacent natural cover.

graphic displaying indicator species score results

The monitoring results pinpoint the need for conservation management in urbanizing regions to focus beyond the preservation of habitat and habitat connections (habitat quantity).

If we are to maximize the value of investments made in land preservation, we need also to identify, measure, and manage those urban impacts that affect neighbouring natural areas, to protect and enhance the quality of that habitat for species. Success will be evident through enhanced biodiversity quality as measured through a biodiversity quality index such as the ISS.

montage of images of urban wildlife
Many regional species are in decline in the urban zone as their habitat is impacted by increased recreational use, road density, altered hydrology, creation of informal trails, and other influences from the surrounding landscape.

The full article can be accessed free of charge through Science Direct until December 25, 2017.

Toronto and Region Conservation would like to thank the numerous volunteers who dedicated their time and effort over the years in collecting valuable monitoring data that made the creation of the Indicator Species Score possible. We would also like to acknowledge the landowners who have hosted monitoring sites, for their hospitality and interest in ecosystem protection.

Through scientific data collection, TRCA’s Environmental Monitoring and Data Management team tell the stories about the changes affecting the natural areas and watercourses within our regions.  For more information, please visit our webpage, follow us on Twitter, subscribe to our Monitoring Matters  e-newsletter, or visit our YouTube playlist.