Systems of protected and conserved areas will not deliver global biodiversity outcomes effectively if they do not include sufficient representation of the world’s ecosystems and species, a fact acknowledged through Aichi Target 11’s ‘ecologically representative’ wording. The coverage of ecoregions1 is generally used to assess this element of Target 11 (Gannon et al., 2019), and is the metric used in this analysis.
Since 2010, the number of the 821 terrestrial ecoregions2 reaching 17% coverage has increased from 297 to 360 (rising to 365 when OECMs are factored in). The improvement is even more pronounced among the marine realm’s 232 ecoregions, with the number meeting the 10% target more than doubling from 49 to 110 (with no further additions when OECMs are factored in). Furthermore, the combined percentage of marine and terrestrial ecoregions entirely lacking protection (less than 1% coverage by protected areas and OECMs) has decreased from 15.2% to 7.4%. Although the ocean’s 37 pelagic provinces generally have limited protection, the percentage with no protection has dropped steeply from 83.8% in 2010 to 21.6% in 2020.
However, many ecoregions remain under-protected. The 365 terrestrial ecoregions with at least 17% coverage by protected areas and OECMs represent fewer than half (44.5%) of all terrestrial ecoregions. Similarly, the 110 marine ecoregions with at least 10% coverage represent only 47.4% of such ecoregions. This drops further to 10.8% in pelagic provinces, which are considerably larger and fall largely outside national jurisdiction. Methodologies and datasets for assessing coverage of freshwater ecoregions vary, but studies agree they are less than 22% protected in total (Bastin et al., 2019; UNEP-WCMC et al., 2018).
Percentage of biogeographic regions meeting the coverage elements of Aichi Target 11 in 2010 and 2021.
Although some ecoregions contain more biodiversity than others, all ecoregions require at least some form of protection in order for the world’s protected and conserved areas to capture a representative sample of species and ecosystems.
There therefore remains a clear need to improve ecological representation, and attention is particularly needed in ecoregions that lack protection entirely. Ways of increasing ecological representation include greater use of systematic conservation planning (Box 5), and consideration and wider uptake of nationally-differentiated targets (Box 6).
1 Ecological units of land, ocean or freshwater that share similar and geographically-distinct biological characteristics (Olson et al., 2001; Spalding et al., 2012, 2007).
2 Antarctic, Rock and Ice and Lake ecoregions have been excluded.