This indicator is one of a new suite of Protected Area Representativeness and Connectedness (PARC) indices developed by CSIRO (Australia’s national science agency), working in partnership with GEO BON, GBIF and Map of Life. The indicator assesses an important element of Aichi Target 11 – i.e. the extent to which terrestrial protected areas are “ecologically representative”. This assessment is performed at a much finer ecological and spatial resolution than that typically employed in other assessments of protected-area representativeness. The PARC-representativeness indicator is therefore intended to complement existing indicators of ecological representativeness such as Protected Area Coverage of Ecoregions.

PARC-representativeness is generated using a fine-scaled grid covering the entire terrestrial surface of the planet. For each cell in this grid an estimate is derived of the proportional protection of all cells that are ecologically similar to this cell of interest. Ecological similarity between cells is predicted as a function of abiotic environmental surfaces (describing climate, terrain, and soils), scaled using generalised dissimilarity modelling to reflect observed patterns of spatial turnover in species composition, based on best-available occurrence records for plants, vertebrates and invertebrates globally. PARC-representativeness for any given spatial reporting unit (e.g. IPBES region, country) is then derived as a weighted geometric mean of the scores obtained for all cells within that unit, with the contribution of each cell weighted according to its ecological uniqueness.