Largest ever study reveals globally protected areas benefit broad range of species

The most comprehensive assessment of terrestrial protected areas ever to be conducted has shown that globally protected areas are effective at retaining biodiversity.

The study, published in Nature Communications was carried out by scientists from an international team, including the UNEP World Conservation Monitoring Centre. It showed that samples collected within protected areas contain 15 percent more individuals and 11 percent more species compared to samples from unprotected sites.

The Convention on Biological Diversity Programme of Work on Protected Areas states that protected areas are the cornerstones of biodiversity conservation, which is also reflected in Aichi Target 11. Both call for protected areas to be effective.

The research analysed biodiversity samples from 1,939 sites inside and 4,592 sites outside 359 protected areas in 48 countries and 101 ecoregions. The positive impacts of protection were apparent even when protected areas contained land used by humans such as croplands or plantations. However, the results were complex – the location of the protected area (tropical vs temperate) as well as the taxa under consideration influenced whether samples in protected areas contained higher biodiversity. Although samples inside protected areas contained communities with higher numbers of species and individuals, protection did not consistently influence the average range size of individuals in the community, or the variety of ecological niches available.

The research was carried out through the integration of data from two global databases - the PREDICTS database and the World Database on Protected Areas (WDPA). The PREDICTS database ( contains records pertaining to over one percent of terrestrial plant, vertebrate, invertebrate and fungal groups and spans 97 countries and 301 ecoregions. The WDPA is the most complete dataset detailing the world’s terrestrial and marine protected areas and is a joint product of the United Nations Environment Programme and the International Union for Conservation of Nature (IUCN) and made publicly-available by UNEP-WCMC at

Co-lead author of the study, Dr Samantha Hill from the UNEP – World Conservation Monitoring Centre and the Natural History Museum, said:

“Humanity faces difficult decisions as to how best to protect biodiversity while providing for the needs of our ever-growing population. This study – the most taxonomically and geographically representative study of its kind - provides new understanding into the biodiversity found at the intersection of protected areas and human land-uses.”

Dr Jörn Scharlemann, from the University of Sussex, and Honorary Fellow of UNEP-WCMC, said:

“Our results reinforce recent commitments by governments for increased support and recognition of the importance of protected areas worldwide. Governments across the world must be encouraged to continue to improve their effectiveness and to engage their citizens in conserving protected areas for mutual benefit."

The Paper entitled, “Local biodiversity is higher inside than outside terrestrial protected areas worldwide” is published in Nature Communications and can be found here

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