Evaluating sustained community engagement in co-management is critical for designing durable governance with conservation potential, yet such persistence remains rarely assessed. We analyze 750 co-management initiatives established under Chile's Territorial Use Rights for Fishing policy (1998-2021), examining persistence across conditions theorized to shape collective action in social-ecological systems. Survival analysis shows that initiatives had a 75% probability of persisting beyond 15 years. Abandonment risk declined nonlinearly with initial exploitable abundance and increased with monitoring distances. Exploring combinations of variables through cluster analysis reveals that, while initiatives starting with high abundance showed the highest persistence, some initiatives with lower initial abundance also endured at comparable rates when combined with shorter monitoring distances, proximity to large markets, higher poverty, and stronger upwelling. These findings suggest diverse pathways to sustained community engagement in co-management, generate hypotheses for future research, and show how tracking persistence can inform strategies for durable and equitable conservation.

Between 2008 and 2018, the CARE-World Wildlife Fund Alliance implemented an integrated conservation and development project in the Primeiras e Segundas region of Mozambique to address intersecting challenges of poverty, food insecurity and biodiversity loss. The project aimed to catalyze the development of robust community-led governance of coastal resources and generate insights concerning the interplay between conservation and development interventions. After ten years, three of the four communities in this study appear to have been relatively successful in promoting compliance with conservation rules by ensuring the continuity of local enforcement and establishing linkages with district government officials. In contrast, a lack of nested governance and high levels of food insecurity played an important role in the collapse of rule enforcement in the fourth community and continues to generate challenges across all four communities. Overall, the results suggest that external partners should continue offering technical and financial support for community-led governance until fair and effective systems for rule enforcement and nested governance structures have been firmly established. Furthermore, aligning investments in local governance with development interventions can strengthen community support for conservation by addressing underlying drivers of non-compliance and environmental degradation.

Policies create externalities. In conservation, one of the most common types of externalities is leakage, where damages are exported beyond a policy's jurisdictional boundaries. Although much research has measured leakage, little addresses its impact on the lives of people suffering from damages from leakage. This paper develops a comprehensive modeling framework to formalize the dynamics by which individuals and communities exposed to leakage adapt to the challenges posed. Specifically, we use a combination of bio-economic models, abatement curves, and other ethnographically informed analytic modeling to explore the types of damages caused, how communities can adapt to them, and the consequences of such adaptive processes. The theory points to critical system dynamics necessary to understand when and why leakage produces environmental and economic damage. Firstly, the kinds of damages imposed are fundamentally linked to the resource's health, the incentives of those committing leakage, labor market dynamics, and ecosystem services. Secondly, there is no silver bullet for communities adapting to leakage; adaptation is often costly, which means that stopping all the damages from leakage may be infeasible, requiring communities to make the best of a bad situation and allocate precious resources across various strategies. Finally, the strategies adopted to deal with leakage can have far-reaching negative and positive effects, potentially creating cyclical changes in resource stocks, cascades of further leakage or promoting strict property rights that reshape the social landscape.

Forest restoration has become a global priority due to its potential benefits (carbon storage, biodiversity, etc.), but its successful delivery depends on decisions made by people, especially landholders. Despite this, our theory-based understanding of what drives landholders’ decisions to create woodland types important to achieve ecosystem restoration at scale, such as mixed native woodlands which have the highest potential for environmental benefits, remains limited. Building on Diffusion of Innovations Theory, we survey landholders in and around the Cairngorms National Park in Scotland to quantify the effects of woodland creation initiatives, individual landholders’, and contextual characteristics on decisions to create new mixed native woodland using a Bayesian Bernoulli distributed logistic regression. We find that landholders are more likely to have engaged in mixed native woodland creation if they believe it is compatible with their current land use practices; or if they anticipate increases to wildlife habitat or soil quality. Landholders that create mixed native woodland are more likely to perceive interventions to control herbivore damage to new woodland as difficult to understand. Our results suggest that, in contexts with established targets and economic incentives for woodland creation, governments could more effectively promote the uptake of mixed native woodland creation by: emphasising woodlands’ compatibility with other land uses such as agriculture (e.g. agroforestry) or some types of hunting; maintaining or improving the flexibility of woodland creation actions; facilitating access to easy-to-understand evidence-based comparisons of the potential benefits of different woodland types; and supporting landholders’ knowledge needs, especially for herbivore control tasks like fencing. Overall, we show that to achieve ecosystem restoration and its multiple benefits at scale, programme designs need to be more sensitive to landholders’ perspectives whilst incorporating safeguards against negative outcomes.

Evaluating when and under what conditions community engagement in co-management endures is critical for tracking conservation progress and sustaining impact. Yet assessments of initiatives persistence remain rare. We analyze 750 co-management initiatives under Chile’s Territorial Use Rights for Fishing policy (1998–2021), examining persistence across conditions theorized to shape collective action in social-ecological systems. Using cluster analysis, we identified three collective action archetypes and evaluated their persistence with survival analysis. Nationally, initiatives had a 75% probability of lasting beyond 15 years. Those with high initial resource abundance persisted longest (84%). Initiatives with low initial abundance still endured at similar rates under favorable collective action conditions (78%) but had greater abandonment rates when coupled with low poverty, low productivity, and high surveillance costs (54%). These results reveal multiple pathways to lasting co-management, refine hypotheses for future research, and show how tracking persistence supports adaptive, context-specific interventions for durable and equitable conservation.

Climate change is triggering diverse responses from communities across environmental and socioeconomic contexts. In African rangelands, selling livestock is critical for adapting to changes in environmental conditions. As these decisions further affect environmental and community wellbeing, identifying where, when, and how livestock sales are expected to respond to particular climatic shifts is important for delineating the total impact of climate change and responding accordingly. Scattered evidence suggests that socioeconomic wellbeing moderates how communities use cattle sales in response to precipitation. However, this has not been quantified as a generalizable trend across spatial and temporal scales. This study examines the relationship between socioeconomic wellbeing (using a standard deprivation index), precipitation, and monthly cattle slaughtering across South Africa from 2015 to 2022. We find that in better-off provinces (-1 standard deviation of deprivation), expected cattle slaughtering declined from 73,296 (90 % CI: 38,430-130,709) under the highest observed precipitation, to 57,897 (90 % CI: 30,431-103,378) in response to the lowest observed precipitation. In contrast, worse-off provinces (+1 standard deviation), increased expected cattle slaughtering from 10,306 (90 % CI: 5916-19,753) under high precipitation, to 19,966 (90 % CI: 11,437-38,245) after low precipitation. We further investigate this dynamic using a novel statistical disaggregation procedure, showing similar effects at a 16-km scale for the year 2020 and producing high-resolution estimates of where slaughtering was most likely given socioeconomic and environmental conditions. Our findings show that poorer communities are more likely to sell cattle in response to drought, a practice that can erode long-term resilience and deepen inequities.

Community-based natural resource management is a common strategy for conserving biodiversity, but little is known about how such initiatives can scale appropriately and widely. We interviewed 80 experts across 5 widely adopted community-based initiatives (in Chile, Nepal, Namibia, Madagascar, and Fiji) to understand their perspectives on the drivers of adoption and spread. We used general elimination methodology and diffusion of innovation theory to identify and rule out possible explanations. Factors consistently considered influential were economic and social benefits, compatibility with needs, support and facilitation by extension agencies, and the presence of international organizations. Initiatives aiming to scale should be designed to be flexible and aligned with adopters' needs, and external organizations should coordinate resources for scaling out. Dependence on external support underscores the need for quality assistance, good practices by external actors, and understanding power relations and fairness, as well as the need to temper donor and policy expectations of scaling beyond supported and appropriate sites.

Abstract Forest restoration can potentially contribute to multiple global sustainable development goals. Yet, little is known about the factors associated with local actors' choice to engage in restoration, limiting the development of effective scaling strategies. Our study examines the spatial socio‐ecological factors associated with landowners' engagement in forest restoration, documented by the Atlantic Forest Restoration Pact in Brazil. We draw on Diffusion of Innovations theory to model associations between forest restoration and explanatory variables among 222,000 private properties in the Atlantic Forest. Properties with the highest cattle densities were 163.9% more likely to be restored (95% CI: 131.1%–201.3%) than those with the lowest. Large properties had a 120.0% higher restoration probability (95% CI: 90.9%–153.5%) than medium ones. Compared to reference levels, associations between forest cover (in 2010) and restoration probability were ambiguous, but properties with greater forest loss (1990–2010) were 9.0% less likely to be restored (95% CI: −12.5% to −5.3%). Properties with water bodies were 22.2% more likely to be restored (95% CI: 8.9%–37.1%), while upland properties were 46.6% less likely (95% CI: 32.3%–57.8%), and those with the highest ruggedness 22.2% less likely (95% CI: 12.4%–30.9%). Longer travel times to urban areas reduced restoration likelihood by 48.3% (95% CI: 39.7%–55.8%). Properties in the highest road distance quantile were 11.1% more likely to be restored (95% CI: 0.1%–23.2%). High forest management levels reduced restoration likelihood by 52.6% (95% CI: 15.5%–73.6%), while densely populated areas increased it by 53.8% (95% CI: 35.6%–74.4%). Properties in wealthier municipalities were more likely to be restored (54.7%, 95% CI 10.8%–116.4%). Landowners' decision‐making appears responsive to legislative requirements (on minimum forest cover and afforestation around waterbodies), underscoring their value for promoting restoration. Commercial landowners might have greater incentives to restore or be selectively targeted by restoration organisations, risking the marginalisation of smallholders in poorer areas from restoration agendas. Engagement with forest restoration is highest where there are more people and lower travel times to cities, suggesting restoration can potentially deliver ecological benefits in some of Brazil's most degraded landscapes. Read the free Plain Language Summary for this article on the Journal blog.

Achieving global climate and biodiversity goals will require the rapid adoption of conservation initiatives across communities, regions, and, in some cases, the planet. However, the non-linearity and variability of adoption processes limit efforts to assess whether initiatives are on track to meet scaling targets. This uncertainty hampers practitioners’ and policymakers’ ability to adaptively allocate resources to accelerate scaling. Here, we adapt epidemiological models to forecast adoption patterns of 19 conservation initiatives, isolating the effects of independently and socially learned adoption. Our models forecast cumulative adoption with an average error of 15.9% and net adoption with a 19.6% error, indicating they reliably forecast future scaling trajectories based on early trends and capture key underlying processes. Moreover, these models offer inference regarding the mechanisms driving adoption, providing a comprehensive strategy for iteratively and adaptively identifying management actions to shape the scale of conservation initiatives.

Many attempts to scale conservation actions have failed to deliver their intended benefits, caused unintended harm, or later been abandoned, hampering efforts to bend the curve on biodiversity loss. Here, we encourage those calling for scaling to pause and reflect on past scaling efforts, which offer valuable lessons: the total impact of an action depends on both its effectiveness and scalability; effectiveness can change depending on scale for multiple reasons, feedback processes can change socio-ecological conditions influencing future adoption, and the drive to scale can incentivise bad practices that undermine long-term outcomes. Cutting across these themes is the recognition that monitoring scaling can enhance evidence-informed adaptive management, reporting, and research. We draw on evidence and concepts from disparate fields, explore novel linkages between often isolated concepts, and suggest strategies for practitioners, policymakers, and researchers. Reflecting on these five lessons may help scale effective conservation actions in responsible ways to meet the triple goals of reversing biodiversity loss, combating climate change, and supporting human well-being.

Archaeology and cultural evolution theory both predict that environmental variation and population size drive the likelihood of inventions (via individual learning) and their conversion to population-wide innovations (via social uptake). We use the case study of the adoption of the bow and arrow in the Great Basin to infer how patterns of cultural variation, invention, and innovation affect investment in new technologies over time and the conditions under which we could predict cultural innovation to occur. Using an agent-based simulation to investigate the conditions that manifest in the innovation of technology, we find the following: (1) increasing ecological variation results in a greater reliance on individual learning, even when this decreases average fitness due to the costs of learning; (2) decreasing population size increases variability in the types of learning strategies that individuals use; among smaller populations drift-like processes may contribute to randomization in interpopulation cultural diffusion; (3) increasing the mutation rate affects the variability in learning patterns at different rates of environmental variation; and (4) increasing selection pressure increases the reliance on social learning. We provide an open-source R script for the model and encourage others to use it to test additional hypotheses. Tanto la arqueologia como la teoria de la evolucion cultural pronostican que la variacion ambiental y el tamano de la poblacion impulsan la probabilidad de invencion (a traves del aprendizaje individual) y su conversion en innovaciones para toda la poblacion (a traves de la aceptacion social). Utilizamos el estudio de caso de la adopcion del arco y la flecha en la Gran Cuenca para inferir como los patrones de variacion, invencion e innovacion culturales afectan la inversion en nuevas tecnologias a lo largo del tiempo y las condiciones bajo las cuales podriamos pronosticar que ocurrira innovacion cultural. Exploramos este estudio de caso con una simulacion basada en agentes para investigar las condiciones que se manifiestan en la innovacion tecnologica. Encontramos que (1) Un incremento en la variacion ecologica da como resultado una mayor dependencia del aprendizaje individual, incluso cuando esto disminuye la aptitud promedio debido a los costos del aprendizaje, (2) La disminucion del tamano de la poblacion aumenta la variabilidad en los tipos de estrategias de aprendizaje que usan los individuos; entre poblaciones mas pequenas, los procesos tipo deriva pueden contribuir a la aleatorizacion en la difusion cultural entre poblaciones, (3) Un incremento en la tasa de mutacion afecta la variabilidad en los patrones de aprendizaje en diferentes tasas de variacion ambiental, y (4) Un incremento en la presion de seleccion aumenta la dependencia del aprendizaje social. Proporcionamos un script R de codigo abierto para el modelo y animamos a otros a utilizarlo para probar hipotesis adicionales.

Achieving global climate, development, and biodiversity goals will require bringing conservation interventions to scale in suitable contexts and with appropriate timing. Practitioners and policymakers have a range of actions available to influence where, when, and by whom an initiative is adopted. Yet, to make effective management decisions, they must have a clear view of the current trajectory towards scaling goals. The non-linearity and variability of scaling processes has, however, hindered forecasting of adoption trends and environmental outcomes. Here, we adapt models of disease transmission to present a simple and flexible modeling structure for forecasting the adoption of conservation initiatives. We tested this framework on empirical adoption data from 19 distinct initiatives. Specifically, we fit the shape of the adoption timeline during the first half of each initiative, estimating the rates of independent uptake and social transmission up to that point. Forecasting the latter 50% of the timeline of cumulative adoption using just these two parameters resulted in an out-of-sample average error of 15.9% across all observations, indicating that this simple formulation captures much of the data-generating process. In one case, we included data on conservation abandonment, extending the cumulative adoption model to estimate the dropout rate and predicting net adoption with an average error of 19.6%, also indicative that this model captures the empirical process reasonably well. We caution against using such models for long-term forecasts, as they are sensitive to multiple assumptions, but instead advocate for their use in adaptive management. Iterative comparisons of forecasts allow users to retrospectively evaluate the impact of decisions and investments. When combined with estimates of environmental outcomes, our framework may provide a comprehensive modeling strategy for identifying targeted management actions and forecasting the impact of conservation projects while considering dynamic social processes.

With commons encompassing approximately 65% of Earth’s surface and vast tracts of the ocean, a critical challenge for sustainability involves establishing effective institutions for governing these common-pool resources (CPR). While examples of successful governance exist, the circumstances and mechanisms behind their development have often faded from historical records and memories. Drawing on ethnographic work, we introduce a generic evolutionary multigroup modelling framework that examines the emergence, stability and temporal dynamics of collective property rights. Our research reveals a fundamental insight: when intergroup conflicts over resources exist, establishing and enforcing ‘access rights’ becomes an essential prerequisite for evolving sustainable ‘use rights’. These access rights, in turn, enable cultural group selection and facilitate the evolution of sustainable use rights through the imitation of successful groups. Moreover, we identify four crucial aspects within these systems: (1) seizures in CPR systems create individual-level incentives to enforce use and access rights; (2) support for collective property rights is frequency dependent and prone to oscillations; (3) the maximum sustainable yield (MSY) is a tipping point that alters the interplay between individual and group-level selection pressures; (4) success-biased social learning (imitation) of out-group members plays a vital role in spreading sustainable institutions and preventing the tragedy of the commons.

AbstractEarth's forests are continually monitored by both the satellite record and the lived experiences of nearly 2 billion forest‐proximate peoples. Generally, the satellite record summarizes production estimates, such as percent tree cover, at regular, relatively coarse scales. Conversely, local perceptions tend to capture changes at irregular and very fine scales. While the utility of both of these sources of information has been widely demonstrated in isolation, little work has explored in what contexts they are expected to correlate or deviate, or how they might be quantitatively integrated. Here, we collect gridded information on community perceived and remotely sensed mangrove cover change across 719 0.5‐km grids in Pemba Island, Tanzania. We reveal variation in the association between these two data sources across different wards (shehia) and explore the reasons for this variation using interviews and direct observation. We find that shehia with the greatest alignment between perceived and remotely sensed mangrove change tended to have little planting or natural regeneration of mangrove propagules and large areas of complete cover loss. Alternatively, in shehia with the lowest alignment, we find high levels of natural and/or human‐assisted mangrove recolonization and selective harvesting of individual trees and branches. These findings indicate that the alignment between local knowledge and satellite observations of mangrove cover change systematically increases with the scale of change in this system. Finally, we demonstrate a practical workflow for quantitatively leveraging these misalignments by optimizing across both data sources to identify restoration priority areas.

Approximately one quarter of the earth's population directly harvests natural resources to meet their daily needs. These individuals are disproportionately required to alter their behaviors in response to increasing climatic variability and global biodiversity loss. Much of the ever-ambitious global conservation agenda relies on the voluntary uptake of conservation behaviors in such populations. Thus, it is critical to understand how such individuals perceive environmental change and use conservation practices as a tool to protect their well-being. We developed a participatory mapping activity to elicit spatially explicit perceptions of forest change and its drivers across 43 mangrove-dependent communities in Pemba, Tanzania. We administered this activity along with a questionnaire regarding conservation preferences and behaviors to 423 individuals across those 43 communities. We analyzed these data with a set of Bayesian hierarchical statistical models. Perceived cover loss in 50% of a community's mangrove area drove individuals to decrease proposed limits on fuelwood bundles from 2.74 (forest perceived as intact) to 2.37 if participants believed resultant gains in mangrove cover would not be stolen by outsiders. Conversely, individuals who believed their community mangrove forests were at high risk of theft loosened their proposed harvest limits from 1.26 to 2.75 bundles of fuelwood in response to the same perceived forest decline. High rates of intergroup competition and mangrove loss were thus driving a self-reinforcing increase in unsustainable harvesting preferences in community forests in this system. This finding demonstrates a mechanism by which increasing environmental decline may cause communities to forgo conservation practices, rather than adopt them, as is often assumed in much community-based conservation planning. However, we also found that when effective boundaries were present, individuals were willing to limit their own harvests to stem such perceived decline.

While many successful initiatives for conserving nature exist, efforts to take them to scale have been inadequate. Moreover, conservation science currently lacks a systematic methodology for determining if or when interventions will reach effective scales and how programmatic decisions will affect the scaling process. This paper presents a modelling framework that aims to address both issues by operationalizing Diffusion of Innovations theory and local knowledge using agent-based modelling and Bayesian inference. By applying our framework to existing data on the spatiotemporal adoption of a community-based marine management initiative in Fiji, we demonstrate that our approach can identify the mechanisms that govern the observed adoption patterns. In this case, the relative advantage of the intervention, village social networks, and perceived knowledge stand out as important drivers of adoption. Using the identified causal processes, our approach can forecast business-as-usual and counterfactual future scenarios and hence inform conservation policy. Finally, we highlight the importance of spatiotemporal data for making detailed scaling predictions. We structure the paper as a step-by-step guide, highlighting our modelling decisions and possible limitations. Thus, besides presenting a case study, this paper serves as a template for practitioners and researchers to better model the scaling process of other conservation interventions. ### Competing Interest Statement The authors have declared no competing interest.

Many attempts to scale conservation actions have failed to deliver their intended benefits, caused unintended harm or later been abandoned, hampering efforts to bend the curve on biodiversity loss. Here we encourage those calling for scaling to pause and reflect on past scaling efforts, which offer valuable lessons: the total impact of an action depends on both its effectiveness and scalability; effectiveness can change depending on scale for multiple reasons; feedback processes can change socio-ecological conditions influencing future adoption; and the drive to scale can incentivize bad practices that undermine long-term outcomes. Cutting across these themes is the recognition that monitoring scaling can enhance evidence-informed adaptive management, reporting and research. We draw on evidence and concepts from disparate fields, explore new linkages between often isolated concepts and suggest strategies for practitioners, policymakers and researchers. Reflecting on these five lessons may help in the scaling of effective conservation actions in responsible ways to meet the triple goals of reversing biodiversity loss, combating climate change and supporting human wellbeing. This Perspective encourages conservation practitioners to learn from past efforts to scale conservation actions in the hope that enhanced understanding of linkages between scaling, effectiveness and social justice will benefit future attempts to scale up, out and deep.

Ambient wildfire smoke in the American West has worsened considerably in recent decades, while the number of individuals recreating outdoors has simultaneously surged. Wildfire smoke poses a serious risk to human health, especially during long periods of exposure and during exercise. As such, evaluating whether people modify recreation in response to smoke is important to understanding the public health implications of these trends. Here we aggregate data on black carbon, a major component of wildfire smoke, and recreational visitation in 32 US national parks from 1980 to 2019 to examine how visitors respond to wildfire smoke. We hypothesize that visitor response may exhibit a threshold effect where ambient smoke reduces visitation after a critical level, but not before. We develop a series of breakpoint models to test this hypothesis. The results of these models are mixed, but overall show little to no effect of ambient smoke on visitation to the 32 parks tested, even when allowing for critical thresholds at the extreme upper ranges of smoke exposure. This indicates that wildfire smoke does not greatly alter park attendance. This finding suggests that management actions to protect visitor health during smoke events may be warranted.

Coconut crabs Birgus latro are listed as vulnerable by the IUCN due to habitat conversion and fragmentation as well as direct exploitation for human consumption. Here, we document the distribution of coconut crabs in 81 coastal wards (shehia) across the island of Unguja, Zanzibar, and its outlying islets using standardised interviews and night-time fieldwork. Coconut crabs are mostly absent from the main island of Unguja but are found on 14 of 22 small outlying islands. We matched the distribution on the main island to environmental, social and economic data at the ward level. Our analyses show that coconut crabs are more likely to be present in wards containing rocky as opposed to sandy coastlines, and less likely to be found in wards with hotels and urbanisation, a finding of broad relevance for coastal populations of other species. Our findings show that a new government initiative for economic improvement that encourages construction of hotels on small islets around Unguja needs considerable oversight to prevent threatening the long-term viability of this vulnerable species in one of its last areas in the Western Indian Ocean. In addition, full formal protection of this species will reduce further population fragmentation.