McIntosh et al. Environ Evid (2018) 7:22 https://doi.org/10.1186/s13750-018-0134-2 SYSTEMATIC MAP Absence of evidence for the conservation outcomes of systematic conservation planning around the globe: a systematic map Emma J. McIntosh 1* , Sarah Chapman 2 , Stephen G. Kearney 2 , Brooke Williams 2 , Glenn Althor 2 , Jessica P. R. Thorn 3 , Robert L. Pressey 4 , Madeleine C. McKinnon 5 and Richard Grenyer 1 Abstract Background: Systematic conservation planning is a discipline concerned with the prioritisation of resources for bio- diversity conservation and is often used in the design or assessment of terrestrial and marine protected area networks. Despite being an evidence-based discipline, to date there has been no comprehensive review of the outcomes of systematic conservation plans and assessments of the relative efectiveness of applications in diferent contexts. To address this fundamental gap in knowledge, our primary research question was: what is the extent, distribution and robustness of evidence on conservation outcomes of systematic conservation planning around the globe? Methods: A systematic mapping exercise was undertaken using standardised search terms across 29 sources, includ- ing publication databases, online repositories and a wide range of grey literature sources. The review team screened articles recursively, frst by title only, then abstract and fnally by full-text, using inclusion criteria related to systematic conservation plans conducted at sub-global scales and reported on since 1983. We sought studies that reported out- comes relating to natural, human, social, fnancial or institutional outcomes and which employed robust evaluation study designs. The following information was extracted from included studies: bibliographic details, background infor- mation including location of study and broad objectives of the plan, study design, reported outcomes and context. Results: Of the approximately 10,000 unique articles returned through our searches, 1209 were included for full-text screening and 43 studies reported outcomes of conservation planning interventions. However, only three studies involved the use of evaluation study designs which are suitably rigorous for inclusion, according to best-practice guidelines. The three included studies were undertaken in the Gulf of California (Mexico), Réunion Island, and The Nature Conservancy’s landholdings across the USA. The studies varied widely in context, purpose and outcomes. Study designs were non-experimental or qualitative, and involved use of spatial landholdings over time, stakeholder surveys and modelling of alternative planning scenarios. Conclusion: Rigorous evaluations of systematic conservation plans are currently not published in academic journals or made publicly available elsewhere. Despite frequent claims relating to positive implications and outcomes of these planning activities, we show that evaluations are probably rarely conducted. This fnding does not imply systematic conservation planning is not efective but highlights a signifcant gap in our understanding of how, when and why it may or may not be efective. Our results also corroborate claims that the literature on systematic conservation planning is dominated by methodological studies, rather than those that focus on implementation and outcomes, and support the case that this is a problematic imbalance in the literature. We emphasise the need for academics and practitioners to publish the outcomes of systematic conservation planning exercises and to consider employing © The Author(s) 2018. This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/ publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated. Open Access Environmental Evidence *Correspondence: emma.mcintosh@ouce.ox.ac.uk 1 School of Geography and the Environment, University of Oxford, Oxford, UK Full list of author information is available at the end of the article