Abstract
International policy is focused on increasing the proportion of the Earth’s surface that is protected for nature1,2. Although studies show that protected areas prevent habitat loss3–6, there is a lack of evidence for their effect on species’ populations: existing studies are at local scale or use simple designs that lack appropriate controls7–13. Here we explore how 1,506 protected areas have affected the trajectories of 27,055 waterbird populations across the globe using a robust before–after control–intervention study design, which compares protected and unprotected populations in the years before and after protection. We show that the simpler study designs typically used to assess protected area effectiveness (before–after or control–intervention) incorrectly estimate effects for 37–50% of populations—for instance misclassifying positively impacted populations as negatively impacted, and vice versa. Using our robust study design, we find that protected areas have a mixed impact on waterbirds, with a strong signal that areas managed for waterbirds or their habitat are more likely to benefit populations, and a weak signal that larger areas are more beneficial than smaller ones. Calls to conserve 30% of the Earth’s surface by 2030 are gathering pace14, but we show that protection alone does not guarantee good biodiversity outcomes. As countries gather to agree the new Global Biodiversity Framework, targets must focus on creating and supporting well-managed protected and conserved areas that measurably benefit populations.
| Originalsprog | Engelsk |
|---|---|
| Tidsskrift | Nature |
| Vol/bind | 605 |
| Sider (fra-til) | 103-107 |
| ISSN | 0028-0836 |
| DOI | |
| Status | Udgivet - 2022 |
Bibliografisk note
Funding Information:We thank the coordinators, thousands of volunteer counters, and funders of the International Waterbird Census. This data collection effort is funded by the Ministry of the Environment of Japan, Environment Canada, AEWA Secretariat, EU LIFE+ NGO Operational Grant, MAVA Foundation, Swiss Federal Office for Environment and Nature, French Ministry of Environment and Sustainable Development, UK Department of Food and Rural Affairs, Norwegian Nature Directorate, Dutch Ministry of Economics, Agriculture and Innovation, DOB Ecology and Wetlands International members. CBC Data is provided by National Audubon Society and through the generous efforts of Bird Studies Canada and countless volunteers across the western hemisphere. H.S.W. was funded by a Cambridge–Australia Poynton Scholarship, Cambridge Department of Zoology J. S. Gardiner Studentship and Cambridge Philosophical Society Grant. H.S.W. and B.I.S. are funded by the Royal Commission for the Exhibition of 1851. W.J.S. was funded by Arcadia, The David and Claudia Harding Foundation and MAVA. J.P.G.J. was supported by a visiting fellowship to Fitzwilliam College Cambridge. This work was performed using resources provided by the Cambridge Service for Data Driven Discovery (CSD3) operated by the University of Cambridge Research Computing Service ( www.csd3.cam.ac.uk ), provided by Dell EMC and Intel using Tier-2 funding from the Engineering and Physical Sciences Research Council (capital grant EP/P020259/1), and DiRAC funding from the Science and Technology Facilities Council ( www.dirac.ac.uk ). Finally, the authors would like to acknowledge the use of the University of Exeter High-Performance Computing (HPC) facility in carrying out this work.
Publisher Copyright:
© 2022, The Author(s), under exclusive licence to Springer Nature Limited.