Global priority areas for ecosystem restoration.

Extensive ecosystem restoration is increasingly seen as being central to conserving biodiversity1 and stabilizing the climate of the Earth2. Although ambitious national and global targets have been set, global priority areas that account for spatial variation in benefits and costs have yet to be identified. Here we develop and apply a multicriteria optimization approach that identifies priority areas for restoration across all terrestrial biomes, and estimates their benefits and costs. We find that restoring 15% of converted lands in priority areas could avoid 60% of expected extinctions while sequestering 299 gigatonnes of CO2-30% of the total CO2 increase in the atmosphere since the Industrial Revolution. The inclusion of several biomes is key to achieving multiple benefits. Cost effectiveness can increase up to 13-fold when spatial allocation is optimized using our multicriteria approach, which highlights the importance of spatial planning. Our results confirm the vast potential contributions of restoration to addressing global challenges, while underscoring the necessity of pursuing these goals synergistically.

Predicting landscape-scale biodiversity recovery by natural tropical forest regrowth.

Natural forest regrowth is a cost-effective, nature-based solution for biodiversity recovery, yet different socioenvironmental factors can lead to variable outcomes. A critical knowledge gap in forest restoration planning is how to predict where natural forest regrowth is likely to lead to high levels of biodiversity recovery, which is an indicator of conservation value and the potential provisioning of diverse ecosystem services. We sought to predict and map landscape-scale recovery of species richness and total abundance of vertebrates, invertebrates, and plants in tropical and subtropical second-growth forests to inform spatial restoration planning. First, we conducted a global meta-analysis to quantify the extent to which recovery of species richness and total abundance in second-growth forests deviated from biodiversity values in reference old-growth forests in the same landscape. Second, we employed a machine-learning algorithm and a comprehensive set of socioenvironmental factors to spatially predict landscape-scale deviation and map it. Models explained on average 34% of observed variance in recovery (range 9-51%). Landscape-scale biodiversity recovery in second-growth forests was spatially predicted based on socioenvironmental landscape factors (human demography, land use and cover, anthropogenic and natural disturbance, ecosystem productivity, and topography and soil chemistry); was significantly higher for species richness than for total abundance for vertebrates (median range-adjusted predicted deviation 0.09 vs. 0.34) and invertebrates (0.2 vs. 0.35) but not for plants (which showed a similar recovery for both metrics [0.24 vs. 0.25]); and was positively correlated for total abundance of plant and vertebrate species (Pearson r = 0.45, p = 0.001). Our approach can help identify tropical and subtropical forest landscapes with high potential for biodiversity recovery through natural forest regrowth.

Predicción de la Recuperación de la Biodiversidad a Escala de Paisaje según la Regeneración Natural del Bosque Tropical Resumen La regeneración natural del bosque es una solución rentable para la recuperación de la biodiversidad basada en la naturaleza, sin embargo, los diferentes factores socioambientales pueden derivar en resultados variables. Cómo predecir la ubicación en donde la regeneración natural del bosque recuperará los niveles de biodiversidad, los cuales son un indicador del valor de la conservación y un suministro potencial de diferentes servicios ambientales, es un vacío de conocimiento importante en la planeación de la restauración forestal. Buscamos predecir y mapear la recuperación a escala de paisaje de la riqueza de especies y la abundancia total de vertebrados, invertebrados y plantas en bosques tropicales y subtropicales de segundo crecimiento para guiar la planeación de la restauración. Primero, realizamos un metaanálisis mundial para cuantificar la medida a la que se desvió la recuperación de la riqueza y la abundancia total de especies en los bosques de segundo crecimiento de los valores de biodiversidad en los bosques antiguos referenciales en el mismo paisaje. Después, utilizamos un algoritmo de aprendizaje automático y un conjunto integral de factores socioambientales para predecir espacialmente la desviación a escala de paisaje para después mapearla. Los modelos explicaron en promedio el 34% de la varianza observada en la recuperación (rango de 9-51%). La recuperación de la biodiversidad a escala de paisaje en los bosques de segundo crecimiento pudo predecirse espacialmente con base en los factores socioambientales del paisaje (demografía humana, uso y cobertura del suelo, alteraciones naturales y antropogénicas, productividad del ecosistema, tipo de topografía y de suelo); fue significativamente más alta para la riqueza de especies que para la abundancia total de vertebrados (desviación media pronosticada ajustada al rango de 0.09 versus 0.34) e invertebrados (0.2 versus 0.35) pero no para las plantas (las cuales mostraron una recuperación similar para ambas medidas [0.24 versus 0.25]); y tuvo una correlación positiva para la abundancia de especies de plantas y vertebrados (Pearson r =0.45, p=0.001). Nuestra estrategia puede ayudar a identificar los paisajes de bosques tropicales y subtropicales con un potencial alto para la recuperación de la biodiversidad por medio de la regeneración natural del bosque.

Global rarity of intact coastal regions.

Management of the land-sea interface is essential for global conservation and sustainability objectives because coastal regions maintain natural processes that support biodiversity and the livelihood of billions of people. However, assessments of coastal regions have focused strictly on either the terrestrial or marine realm. Consequently, understanding of the overall state of Earth's coastal regions is poor. We integrated the terrestrial human footprint and marine cumulative human impact maps in a global assessment of the anthropogenic pressures affecting coastal regions. Of coastal regions globally, 15.5% had low anthropogenic pressure, mostly in Canada, Russia, and Greenland. Conversely, 47.9% of coastal regions were heavily affected by humanity, and in most countries (84.1%) >50% of their coastal regions were degraded. Nearly half (43.3%) of protected areas across coastal regions were exposed to high human pressures. To meet global sustainability objectives, all nations must undertake greater actions to preserve and restore the coastal regions within their borders.

costa, huella humana, impacto humano cumulativo, litoral, presión humana, restauración, tierras vírgenes Resumen El manejo de la interfaz entre la tierra y el mar es esencial para los objetivos mundiales de conservación y sustentabilidad ya que las regiones costeras mantienen los procesos naturales que sostienen a la biodiversidad y al sustento de miles de millones de personas. Sin embargo, los análisis de las regiones costeras se han enfocado estrictamente en el ámbito marino o en el terrestre, pero no en ambos. Por consiguiente, el conocimiento del estado general de las regiones costeras del planeta es muy pobre. Integramos la huella terrestre humana y mapas marinos del impacto humano cumulativo en un análisis global de las presiones antropogénicas que afectan las áreas costeras. De las áreas costeras de todo el mundo, el 15.5% tuvieron una presión antropogénica reducida, principalmente en Canadá, Rusia y Groenlandia. En cambio, el 47.9% de las regiones costeras estuvieron fuertemente afectas por la humanidad, y en la mayoría de los países (84.1%) >50% de sus regiones litorales se encuentran degradadas. Casi la mitad (43.3%) de las áreas protegidas en las regiones costeras tienen un grado de exposición a fuertes presiones humanas. Para cumplir los objetivos mundiales de sustentabilidad, todos los países deben emprender mejores acciones para preservar y restaurar las regiones litorales dentro de sus fronteras.

Global forest restoration opportunities to foster coral reef conservation.

Sediment runoff from disturbed coastal catchments is a major threat to marine ecosystems. Understanding where sediments are produced and where they are delivered enables managers to design more effective strategies for improving water quality. A management strategy is targeted restoration of degraded terrestrial areas, as it provides opportunities to reduce land-based runoff from coastal areas and consequently foster coral reef conservation. To do this strategically, a systematic approach is needed to identify watersheds where restoration actions will provide the highest conservation benefits for coral reefs. Here, we develop a systematic approach for identifying global forest restoration opportunities that would also result in large decreases in the flux of sediments to coral reefs. We estimate how land-use change affects sediment runoff globally using high-resolution spatial data and determine the subsequent risk of sediment exposure on coral reefs using a diffusion-based ocean transport model. Our results reveal that sediment export is a major issue affecting 41% of coral reefs globally. The main coastal watersheds with the highest sediment export are predominantly located in Southeast Asian countries, with Indonesia and the Philippines accounting for 52% of the sediment export in coastal areas near coral reefs. We show how restoring forest across multiple watersheds could help to reduce sediment export to 63,000 km2 of coral reefs. Although reforestation opportunities in areas that discharge onto coral reefs are relatively small across watersheds, it is possible to achieve large sediment reduction benefits by strategically targeting watersheds located in regions with a high density of corals near to the coast. Thus, reforestation benefits on coral reefs do not necessarily come from the watersheds that produce the highest sediment export. These analyses are key for generating informed action to support both international conservation policy and national restoration activities.

Multinational coordination required for conservation of over 90% of marine species.

Marine species are declining at an unprecedented rate, catalyzing many nations to adopt conservation and management targets within their jurisdictions. However, marine species and the biophysical processes that sustain them are naive to international borders. An understanding of the prevalence of cross-border species distributions is important for informing high-level conservation strategies, such as bilateral or regional agreements. Here, we examined 28,252 distribution maps to determine the number and locations of transboundary marine plants and animals. More than 90% of species have ranges spanning at least two jurisdictions, with 58% covering more than 10 jurisdictions. All jurisdictions have at least one transboundary species, with the highest concentrations of transboundary species in the USA, Australia, Indonesia, and the Areas Beyond National Jurisdiction. Distributions of mapped biodiversity indicate that overcoming the challenges of multinational governance is critical for a much wider suite of species than migratory megavertebrates and commercially exploited fish stocks-the groups that have received the vast majority of multinational management attention. To effectively protect marine biodiversity, international governance mechanisms (particularly those related to the Convention on Biological Diversity, the Convention on Migratory Species, and Regional Seas Organizations) must be expanded to promote multinational conservation planning, and complimented by a holistic governance framework for biodiversity beyond national jurisdiction.

Smart allocation of restoration funds over space and time.

A challenge for natural area managers is to ensure that public expenditure on land restoration is cost effective, efficient and transparent but this is difficult to achieve in practice, especially when there are many possible projects across multiple years. Here we develop a "roadmap" for investment in land restoration. It explicitly considers space, time and their interaction, in relation to ecological outcomes and restoration costs (and their variation in time and space). Using integer linear programming optimization in a benefit-cost accounting framework, the roadmap incorporates: transitions between different stages of ecological recovery in a spatial mosaic of multiple ecosystem types; cost schedules associated with managing those transitions over time; time lags between beginning management and achieving outcomes; variations to constraints and goals associated with various factors including site accessibility, specific conservation priorities (such as threatened species or ecosystems); and background environmental trends. This approach enables land managers to: (1) forecast landscape-scale outcomes of management strategies over long timeframes; (2) address the question of how long it will take and how much it will cost to achieve specific outcomes; and (3) explore potential trade-offs in outcomes among alternative management strategies. We illustrate its application using a case study of forest restoration in Australia by a local government authority across a public conservation estate comprising 765 land units of varying size, totaling ˜13,000 ha, across five different floristic vegetation types, with an annual budget of ˜AU$5M, projected over a 50-yr timeframe. These simulations revealed a trade-off between management strategies that seek to increase either the total cover of native forest or the amount of high quality forest: quality-based strategies were favored in scenarios in which shorter term (20-30 yr) timeframes were chosen at the outset, but cover-based strategies were favored if longer time horizons were initially targeted. Projected outcomes were also strongly influenced by assumed background rates of vegetation decline or recovery. Many of the issues in this restoration roadmap are generalizable (even though specific outcomes and trade-offs are likely to vary among case studies), and the approach is both scalable and transferable to other regions and ecosystems.

Commensal bacterial sharing does not predict host social associations in kangaroos.

Social network analysis has been postulated as a tool to study potential pathogen transmission in wildlife but is resource-intensive to quantify. Networks based on bacterial genotypes have been proposed as a cost-effective method for estimating social or transmission network based on the assumption that individuals in close contact will share commensal bacteria. However, the use of network analysis to study wild populations requires critical evaluation of the assumptions and parameters these models are founded on. We test (a) whether networks of commensal bacterial sharing are related to hosts' social associations and hence could act as a proxy for estimating transmission networks, (b) how the parameters chosen to define host associations and delineate bacterial genotypes impact inference and (c) whether these relationships change across time. We use stochastic simulations to evaluate how uncertainty in parameter choice affects network structure. We focused on a well-studied population of eastern grey kangaroos (Macropus giganteus), from Sundown National Park, Australia. Using natural markings, each individual was identified and its associations with other kangaroos recorded through direct field observations over 2 years to construct social networks. Faecal samples were collected, Escherichia coli was cultured and genotyped using BOX-PCR, and bacterial networks were constructed. Two individuals were connected in the bacterial network if they shared at least one E. coli genotype. We determined the capacity of bacterial networks to predict the observed social network structure in each year. We found little support for a relationship between social association and dyadic commensal bacterial similarity. Thresholds to determine host associations and similarity cut-off values used to define E. coli genotypes had important ramifications for inferring links between individuals. In fact, we found that inferences can show opposite patterns based on the chosen thresholds. Moreover, no similarity in overall bacterial network structure was detected between years. Although empirical disease transmission data are often unavailable in wildlife populations, both bacterial networks and social networks have limitations in representing the mode of transmission of a pathogen. Our results suggest that caution is needed when designing such studies and interpreting results.

El análisis de redes sociales se ha postulado como una herramienta para estudiar la potencial transmisión de patógenos en fauna silvestre. Sin embargo, las redes sociales en fauna silvestre son difíciles de cuantificar. Es por esto que las redes basadas en el genotipo bacteriano se han propuesto como un método más rentable para estimar redes sociales o de transmisión, basado en el supuesto de que individuos en contacto cercano compartirán bacterias comensales. Sin embargo, el uso del análisis de redes para estudiar poblaciones silvestres requiere una evaluación crítica de los supuestos y parámetros en los que se basan estos métodos. En este estudio probamos (a) si las redes de bacterias comensales están relacionadas con las redes sociales y por lo tanto podrían actuar como proxy para estimar redes de transmisión. Exploramos (b) cómo los parámetros elegidos, para definir asociaciones entre individuos y delinear genotipos bacterianos, impactan en los resultados. Finalmente, examinamos (c) si estas relaciones cambian con el tiempo. Utilizamos simulaciones estocásticas para evaluar cómo la incertidumbre en la elección de parámetros afecta la estructura de la red. Nuestro estudio se basó en una población de canguros grises (Macropus giganteus), del Parque Nacional de Sundown, Australia. Cada individuo fue identificado usando marcas naturales, y sus interacciones con otros canguros se registraron a través de observaciones de campo durante dos años para construir redes sociales. Se recolectaron muestras fecales, se cultivó Escherichia coli, se determinó el genotipo mediante BOX-PCR y se construyeron las redes bacterianas. El criterio para conectar dos individuos en la red bacteriana, se basa en sí al menos un genotipo de E. coli es compartido entre dos individuos. Determinamos la capacidad de las redes bacterianas para predecir la estructura de las redes sociales observadas en cada año. Encontramos poca evidencia que sustente una relación entre la asociación social y la similitud bacteriana. Los umbrales, que determinan las asociaciones entre individuos en las redes sociales y los valores de corte de similitud para definir los genotipos de E. coli, tuvieron una importante influencia para inferir vínculos entre individuos. De hecho, encontramos que las inferencias pueden mostrar patrones opuestos dependiendo de los umbrales elegidos. Además, no se detectó similitud en la estructura de la red bacteriana general entre los años. Aunque los datos empíricos de transmisión de enfermedades a menudo no están disponibles para poblaciones de vida silvestre, los análisis de redes pueden potencialmente solventar dicho problema. Sin embargo, tanto las redes bacterianas como las redes sociales tienen limitaciones para representar el modo de transmisión de un patógeno. Nuestros resultados sugieren que se necesita tener cautela al diseñar este tipo de estudios e interpretar los resultados.

'You shall not pass!': quantifying barrier permeability and proximity avoidance by animals.

Impediments to animal movement are ubiquitous and vary widely in both scale and permeability. It is essential to understand how impediments alter ecological dynamics via their influence on animal behavioural strategies governing space use and, for anthropogenic features such as roads and fences, how to mitigate these effects to effectively manage species and landscapes. Here, we focused primarily on barriers to movement, which we define as features that cannot be circumnavigated but may be crossed. Responses to barriers will be influenced by the movement capabilities of the animal, its proximity to the barriers, and habitat preference. We developed a mechanistic modelling framework for simultaneously quantifying the permeability and proximity effects of barriers on habitat preference and movement. We used simulations based on our model to demonstrate how parameters on movement, habitat preference and barrier permeability can be estimated statistically. We then applied the model to a case study of road effects on wild mountain reindeer summer movements. This framework provided unbiased and precise parameter estimates across a range of strengths of preferences and barrier permeabilities. The quality of permeability estimates, however, was correlated with the number of times the barrier is crossed and the number of locations in proximity to barriers. In the case study we found that reindeer avoided areas near roads and that roads are semi-permeable barriers to movement. There was strong avoidance of roads extending up to c. 1 km for four of five animals, and having to cross roads reduced the probability of movement by 68·6% (range 3·5-99·5%). Human infrastructure has embedded within it the idea of networks: nodes connected by linear features such as roads, rail tracks, pipelines, fences and cables, many of which divide the landscape and limit animal movement. The unintended but potentially profound consequences of infrastructure on animals remain poorly understood. The rigorous framework for simultaneously quantifying movement, habitat preference and barrier permeability developed here begins to address this knowledge gap.

Metapopulation dynamics of rabies and the efficacy of vaccination.

Spatial structure in a host population results in heterogeneity in transmission dynamics. We used a Bayesian framework to evaluate competing metapopulation models of rabies transmission among domestic dog populations in villages in Tanzania. A proximate indicator of disease, medical records of animal-bite injuries, is used to infer the occurrence (presence/absence) of suspected rabid dog cases in one month intervals. State-space models were used to explore the implications of different levels of reporting probability on model parameter estimates. We find evidence for a relatively high rate of infection of these populations from neighbouring districts or from other species distributed throughout the study area, rather than from adjacent wildlife protected areas, suggesting wildlife is unlikely to be implicated in the long-term persistence of rabies. Stochastic simulation of our highest ranked models in vaccinated and hypothetical unvaccinated populations indicated that pulsed vaccination campaigns occurring from 2002 to 2007 reduced rabies occurrence by 57.3 per cent in vaccinated villages in the 1 year following each pulse, and that a similar regional campaign would deliver an 80.9 per cent reduction in occurrence. This work demonstrates how a relatively coarse, proximate sentinel of rabies infection is useful for making inferences about spatial disease dynamics and the efficacy of control measures.

Fine-scale movement decisions of tropical forest birds in a fragmented landscape.

The persistence of forest-dependent species in fragmented landscapes is fundamentally linked to the movement of individuals among subpopulations. The paths taken by dispersing individuals can be considered a series of steps built from individual route choices. Despite the importance of these fine-scale movement decisions, it has proved difficult to collect such data that reveal how forest birds move in novel landscapes. We collected unprecedented route information about the movement of translocated forest birds from two species in the highly fragmented tropical dry forest of Costa Rica. In this pasture-dominated landscape, forest remains in patches or riparian corridors, with lesser amounts of living fencerows and individual trees or "stepping stones." We used step selection functions to quantify how route choice was influenced by these habitat elements. We found that the amount of risk these birds were willing to take by crossing open habitat was context dependent. The forest-specialist Barred Antshrike (Thamnophilus doliatus) exhibited stronger selection for forested routes when moving in novel landscapes distant from its territory relative to locations closer to its territory. It also selected forested routes when its step originated in forest habitat. It preferred steps ending in stepping stones when the available routes had little forest cover, but avoided them when routes had greater forest cover. The forest-generalist Rufous-naped Wren (Campylorhynchus rufinucha) preferred steps that contained more pasture, but only when starting from non-forest habitats. Our results showed that forested corridors (i.e., riparian corridors) best facilitated the movement of a sensitive forest specialist through this fragmented landscape. They also suggested that stepping stones can be important in highly fragmented forests with little remaining forest cover. We expect that naturally dispersing birds and species with greater forest dependence would exhibit even stronger selection for forested routes than did the birds in our experiments.

A contemporary baseline record of the world's coral reefs.

Addressing the global decline of coral reefs requires effective actions from managers, policymakers and society as a whole. Coral reef scientists are therefore challenged with the task of providing prompt and relevant inputs for science-based decision-making. Here, we provide a baseline dataset, covering 1300 km of tropical coral reef habitats globally, and comprised of over one million geo-referenced, high-resolution photo-quadrats analysed using artificial intelligence to automatically estimate the proportional cover of benthic components. The dataset contains information on five major reef regions, and spans 2012-2018, including surveys before and after the 2016 global bleaching event. The taxonomic resolution attained by image analysis, as well as the spatially explicit nature of the images, allow for multi-scale spatial analyses, temporal assessments (decline and recovery), and serve for supporting image recognition developments. This standardised dataset across broad geographies offers a significant contribution towards a sound baseline for advancing our understanding of coral reef ecology and thereby taking collective and informed actions to mitigate catastrophic losses in coral reefs worldwide.

Author Correction: Strategic approaches to restoring ecosystems can triple conservation gains and halve costs.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Group-size-mediated habitat selection and group fusion-fission dynamics of bison under predation risk.

For gregarious animals the cost-benefit trade-offs that drive habitat selection may vary dynamically with group size, which plays an important role in foraging and predator avoidance strategies. We examined how habitat selection by bison (Bison bison) varied as a function of group size and interpreted these patterns by testing whether habitat selection was more strongly driven by the competing demands of forage intake vs. predator avoidance behavior. We developed an analytical framework that integrated group size into resource selection functions (RSFs). These group-size-dependent RSFs were based on a matched case-control design and were estimated using conditional logistic regression (mixed and population-averaged models). Fitting RSF models to bison revealed that bison groups responded to multiple aspects of landscape heterogeneity and that selection varied seasonally and as a function of group size. For example, roads were selected in summer, but not in winter. Bison groups avoided areas of high snow water equivalent in winter. They selected areas composed of a large proportion of meadow area within a 700-m radius, and within those areas, bison selected meadows. Importantly, the strength of selection for meadows varied as a function of group size, with stronger selection being observed in larger groups. Hence the bison-habitat relationship depended in part on the dynamics of group formation and division. Group formation was most likely in meadows. In contrast, risk of group fission increased when bison moved into the forest and was higher during the time of day when movements are generally longer and more variable among individuals. We also found that stronger selection for meadows by large rather than small bison groups was caused by longer residence time in individual meadows by larger groups and that departure from meadows appears unlikely to result from a depression in food intake rate. These group-size-dependent patterns were consistent with the hypothesis that avoidance of predation risk is the strongest driver of habitat selection.

Predation by carpet pythons (Morelia spilota) is an important cause of mortality in a free-living koala (Phascolarctos cinereus) population in South East Queensland.

Koalas (Phascolarctos cinereus) are experiencing significant declines across the northern part of their range. However, unbiased, population-level estimates of mortality are rarely reported, as it's difficult to quantify causes of mortality robustly in this cryptic species. We aimed to determine the relative importance of carpet python (Morelia spilota) predation in a free-living koala population and describe the characteristic pathological findings during necropsy. In total, 503 koalas were captured, underwent veterinary examination and telemetric tagging, and were monitored after release over a four-year period. Mortalities were detected when activity data reported by K-Tracker® biotelemetry collars indicated low or zero activity, or during routine field monitoring events. Experienced koala veterinarians performed thorough, standardised necropsy examinations on retrieved carcasses to determine causes of death. The three, sometimes subtle, cardinal signs used to definitively diagnose carpet python-caused deaths of koalas were a U-shaped primary bite site, slicking of the fur by python saliva (particularly around the face), and diffuse, uniform pulmonary congestion. We found that carpet pythons were important predators of koalas, second only to wild dogs (dingoes and dingo hybrids (Canis familiaris dingo)), accounting for 11.6% of predation deaths and 7.2% of total deaths. Less than half (38%) of the koalas killed by carpet pythons were ingested. Though carpet pythons are known predators of koalas, their relative importance as a cause of mortality hasn't previously been recognised. Population viability analyses and conservation management plans benefit from robust cause-of-death data collected during longitudinal monitoring studies, requiring telemetry methods that facilitate rapid detection of mortalities.

Strategic approaches to restoring ecosystems can triple conservation gains and halve costs.

International commitments for ecosystem restoration add up to one-quarter of the world's arable land. Fulfilling them would ease global challenges such as climate change and biodiversity decline but could displace food production and impose financial costs on farmers. Here, we present a restoration prioritization approach capable of revealing these synergies and trade-offs, incorporating ecological and economic efficiencies of scale and modelling specific policy options. Using an actual large-scale restoration target of the Atlantic Forest hotspot, we show that our approach can deliver an eightfold increase in cost-effectiveness for biodiversity conservation compared with a baseline of non-systematic restoration. A compromise solution avoids 26% of the biome's current extinction debt of 2,864 plant and animal species (an increase of 257% compared with the baseline). Moreover, this solution sequesters 1 billion tonnes of CO2-equivalent (a 105% increase) while reducing costs by US$28 billion (a 57% decrease). Seizing similar opportunities elsewhere would offer substantial contributions to some of the greatest challenges for humankind.

Securing a Long-term Future for Coral Reefs.

Rapid ocean warming as a result of climate change poses a key risk for coral reefs. Even if the goals of the Paris Climate Agreement are achieved, coral reefs are likely to decline by 70-90% relative to their current abundance by midcentury. Although alarming, coral communities that survive will play a key role in the regeneration of reefs by mid-to-late century. Here, we argue for a coordinated, global coral reef conservation strategy that is centred on 50 large (500km2) regions that are the least vulnerable to climate change and which are positioned to facilitate future coral reef regeneration. The proposed strategy and actions should strengthen and expand existing conservation efforts for coral reefs as we face the long-term consequences of intensifying climate change.

The contribution of predators and scavengers to human well-being.

Predators and scavengers are frequently persecuted for their negative effects on property, livestock and human life. Research has shown that these species play important regulatory roles in intact ecosystems including regulating herbivore and mesopredator populations that in turn affect floral, soil and hydrological systems. Yet predators and scavengers receive surprisingly little recognition for their benefits to humans in the landscapes they share. We review these benefits, highlighting the most recent studies that have documented their positive effects across a range of environments. Indeed, the benefits of predators and scavengers can be far reaching, affecting human health and well-being through disease mitigation, agricultural production and waste-disposal services. As many predators and scavengers are in a state of rapid decline, we argue that researchers must work in concert with the media, managers and policymakers to highlight benefits of these species and the need to ensure their long-term conservation. Furthermore, instead of assessing the costs of predators and scavengers only in economic terms, it is critical to recognize their beneficial contributions to human health and well-being. Given the ever-expanding human footprint, it is essential that we construct conservation solutions that allow a wide variety of species to persist in shared landscapes. Identifying, evaluating and communicating the benefits provided by species that are often considered problem animals is an important step for establishing tolerance in these shared spaces.