Global trends in applying decision science in mangrove restoration: are we missing some dimensions?

Mangroves provide significant ecosystem services and are among the world's most effective natural climate solutions, storing large amounts of blue carbon and supporting coastal resilience, biodiversity, and fisheries. Despite their importance, over 64% of mangroves have been lost due to extreme weather and anthropogenic drivers, including market-driven conversion to aquaculture and agriculture. Given that ecosystem degradation stems from social and economic factors influencing land-use decisions, conservation and restoration require consistent socio-ecological integration. Policymakers have been called to safeguard and restore mangroves, and restoration can be cost-effective when implemented correctly. However, global restoration success remains low, with barriers including social, governance, and communication issues, such as land tenure conflicts and limited stakeholder engagement, which can lead to complex negotiations, resource competition, and even human rights violations. Decision science offers structured frameworks and tools to support transparent, participatory decision-making under competing stakeholder preferences, common in restoration contexts. Frameworks like Structured Decision Making and tools such as Spatial Multicriteria Decision Analysis and Analytic Hierarchy Process can integrate diverse knowledge, including Traditional Ecological Knowledge, to set objectives and evaluate opportunities. Increasing social and governance integration, improving stakeholder engagement, and fostering public awareness are essential to overcome barriers. While decision-making research is increasingly called for in marine and coastal management, the application of decision science to mangrove restoration and the extent of social dimension integration remain underexplored. This study aims to analyse trends in decision science for mangrove restoration, identify key topics, frameworks, and tools, and assess how social dimensions are included to provide an overview of applications and needs for improved decision support.

The paper situates its review within a growing body of work calling for decision-making research in marine and coastal conservation and management (e.g., Yang et al., 2022), and notes the increasing integration of social dimensions into marine spatial planning (Gilek et al., 2021). It highlights that, despite these trends, the application of decision science specifically to mangrove restoration and the extent to which social, economic, and governance variables are incorporated remain unclear. The authors reference calls to action for mangrove conservation and restoration (UNEP, 2014) and report documented barriers to restoration success stemming from social and governance issues (Friess et al., 2022; Lovelock and Brown, 2019). The review also acknowledges decision frameworks and tools in conservation literature (Bower et al., 2018; Schwartz et al., 2018) and examples of their application to restoration objectives and wetland restoration opportunities (Guerrero et al., 2017; Martin et al., 2022).

The study employed a systematic literature search designed according to PRISMA-SCR (Tricco et al., 2018). Search terms covered three domains: target ecosystem (e.g., mangrove, blue carbon), management action (e.g., restoration, reforestation, rehabilitation), and decision science (e.g., decision, decision analysis, decision support). Searches were conducted on December 28, 2022 in ISI Web of Science (n=1674) and Scopus (n=1161), yielding 2835 publications. Duplicates (n=611) were removed. Screening assessed relevance based on abstracts mentioning mangrove management/restoration and decision science, reducing to 664 relevant studies for full-text screening. Full-text eligibility applied exclusion criteria for language, literature type, publication type, applicability to decision context, and research type, resulting in 311 papers included that applied comprehensive decision support frameworks or tools for guiding mangrove restoration decisions. The identification and screening were performed using Covidence. Bibliometric analyses were conducted using the Bibliometrix R package (Aria and Cuccurullo, 2017) to assess publication trends, productive countries and cooperation, journals and categories, most cited authors, and co-authorship networks (VOSviewer v1.6.17). Co-authorship analysis considered up to 25 authors per document and a minimum of 3 documents per author. Altmetric Attention Scores (AAS) were obtained from ScienceOpen on September 20, 2023. Keyword co-occurrence analysis (VOSviewer, binary counting) was performed across the 311 abstracts. Keywords were standardised via a synonyms list to avoid duplicates and morphological variants (Table S3). A minimum occurrence threshold of 10 was set; out of 10,176 keywords, 245 met the threshold, and 60% of the most relevant terms (n=147) were analysed to identify topic clusters and temporal trends. Full-text screening identified decision frameworks or tools used, country of application, and variable types (social, economic, ecological) following Wortley et al. (2013). The classification of tools adapted Hemming (2022) with added categories for social tools and economic evaluations. For studies with social variables, methods and tools used were catalogued and variables were classified as pertaining to users/actors or governance systems following McGinnis and Ostrom (2014).

• Publication trends: Mangrove restoration decision science publications rose steadily from 1990 to 2022 with an annual growth rate of 4.4%. Years with the maximum number of publications were 2021 (55) and 2022 (54). Cooperative publications accounted for 46% (178). • Geographic patterns: 44 countries contributed. First author affiliations were most commonly in the United States (13.3%), China (12.9%), and Australia (10.5%). Studies were primarily applied in China (9.6%), India (8.4%), and Indonesia (8.1%), with ~5.6% at a global level. Strong collaborations were observed between the United States–China, United Kingdom–Australia, and China–Australia. • Authorship: 1414 authors across 612 institutions participated. The most prolific authors included F. Dahdouh-Guebas (14 publications; 4.2%), N. Koedam (12), and D. Friess (7). Co-authorship networks revealed main clusters across Belgium, India, Singapore, and Australia, with increasing collaboration in recent years. • Journals: 153 journals published on the topic, predominantly in environmental sciences and ecology. Ocean & Coastal Management was the most common (33 papers, 9.9%), followed by Remote Sensing (10) and Science of the Total Environment (9). • Tools and frameworks: Over 300 decision support tools were identified. Most papers reported decision tools (n=324; 97.8%), while frameworks were sparse (five studies: four Systematic Conservation Planning, one Marine Spatial Planning). Top tool categories: spatial data (n=158), target research and data collection (n=68), social tools (n=62), quantitative models (n=57), and evidence synthesis (n=33). Least reported tools included means-ends diagrams and Delphi technique (n=1 each). Only two decision support systems were found: ICOMIS and CLIMADA. • Topic clusters: Four keyword clusters emerged: (1) ecosystem services and local communities; (2) mapping and land-use change; (3) vegetation and structure; (4) climate change and vulnerability. Temporal trends indicated earlier emphasis on vegetation and structure (2015–2017) and more recent focus on mapping/land use and social-climate dimensions (post-2018). • Variables used: Ecological variables dominated (n=283; 85.5%). Exclusive ecological focus was 67.1%, social-only 7.3%, economic-only 2.1%. Combined dimensions: ecological+social 10.6%, ecological+economic 3.6%, economic+social 5.1%, all three 4.2%. Among social dimension papers, 61.1% addressed users/actors, 11.1% governance systems, and 27.8% both.

The review demonstrates a clear growth in decision-support science for mangrove restoration and highlights the need to integrate social dimensions—particularly governance—into frameworks and tools to improve decision outcomes and on-ground success. While ecological variables remain dominant, there is a notable shift toward social aspects such as vulnerability to climate change, ecosystem services, and community benefits. Collaborative research is essential to fill geographic gaps, especially in regions with significant mangrove losses (e.g., parts of South America, Western Asia, Eastern Asia, and the Caribbean). Decision frameworks like Systematic Conservation Planning show promise in optimising restoration site selection by incorporating stakeholder preferences, sea-level rise projections, fisheries enhancement, and anthropogenic disturbances, and can support landscape multifunctionality and negotiations over land use. Beyond academia, NGOs such as the Global Mangrove Alliance provide practical tools, maps, and best-practice guidelines that integrate social and ecological variables. However, governance-related variables (e.g., land tenure, property-right systems, rules, participation, equity, justice) are underrepresented in decision tools, indicating a critical gap. Delivering actionable, accessible science tailored to practitioner needs and contexts, and understanding barriers to tool uptake, are necessary to enhance practical utility and impact.

The study underscores a growing body of decision-support literature for mangrove restoration, with a historical emphasis on ecological variables and a recent shift toward social dimensions, including climate vulnerability and community benefits. Despite progress, governance and economic variables remain insufficiently integrated. Strengthening international and multidisciplinary cooperation can foster socio-ecological frameworks in decision science, particularly in high-loss regions. While valuable tools, guides, and case studies are emerging from organizations and networks, integrative frameworks that enable participation, transparency, and effective decisions are still needed. Decision frameworks such as Conservation Spatial Planning could help incorporate historically overlooked dimensions. Close collaboration among scientists, NGOs, and practitioners to deliver actionable science is essential to overcome governance and social barriers to successful on-ground restoration.

The review included only English-language, peer-reviewed academic literature and excluded grey literature, which may omit relevant tools and resources and limit representativeness. The exclusion of studies not explicitly designed to advise decisions may have removed potentially useful work that lacks clear articulation of usability. The study did not evaluate the real-world application and uptake of identified tools and frameworks in on-ground projects. The authors note common challenges in research communication and usability, suggesting co-production, clearer tailoring to decision-maker needs, and capacity building to improve interpretation and integration of tools into practice.