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.

Conflicts and opportunities for commercial tree plantation expansion and biodiversity restoration across Brazil.

Substantial global restoration commitments are occurring alongside a rapid expansion in land-hungry tropical commodities, including to supply increasing demand for wood products. Future commercial tree plantations may deliver high timber yields, shrinking the footprint of production forestry, but there is an as-yet unquantified risk that plantations may expand into priority restoration areas, with marked environmental costs. Focusing on Brazil-a country of exceptional restoration importance and one of the largest tropical timber producers-we use random forest models and information on the economic, social, and spatial drivers of historic commercial tree plantation expansion to estimate and map the probability of future monoculture tree plantation expansion between 2020 and 2030. We then evaluate potential plantation-restoration conflicts and opportunities at national and biome-scales and under different future production and restoration pathways. Our simulations show that of 2.8 Mha of future plantation expansion (equivalent to plantation expansion 2010-2020), ~78,000 ha (3%) is forecast to occur in the top 1% of restoration priority areas for terrestrial vertebrates, with ~547,500 ha (20%) and ~1,300,000 ha (46%) in the top 10% and 30% of priority areas, respectively. Just ~459,000 ha (16%) of expansion is forecast within low-restoration areas (bottom 30% restoration priorities), and the first 1 Mha of plantation expansion is likely to have disproportionate impacts, with potential restoration-plantation overlap starkest in the Atlantic Forest but prominent in the Pampas and Cerrado as well. Our findings suggest that robust, coherent land-use policies must be deployed to ensure that significant trade-offs between restoration and production objectives are navigated, and that commodity expansion does not undermine the most tractable conservation gains under emerging global restoration agendas. They also highlight the potentially significant role an engaged forestry sector could play in improving biodiversity outcomes in restoration projects in Brazil, and presumably elsewhere.

Advancing the quantitative characterization of farm animal welfare.

Animal welfare is usually excluded from life cycle assessments (LCAs) of farming systems because of limited consensus on how to measure it. Here, we constructed several LCA-compatible animal-welfare metrics and applied them to data we collected from 74 diverse breed-to-finish systems responsible for 5% of UK pig production. Some aspects of metric construction will always be subjective, such as how different aspects of welfare are aggregated, and what determines poor versus good welfare. We tested the sensitivity of individual farm rankings, and rankings of those same farms grouped by label type (memberships of quality-assurance schemes or product labelling), to a broad range of approaches to metric construction. We found farms with the same label types clustered together in rankings regardless of metric choice, and there was broad agreement across metrics on the rankings of individual farms. We found woodland and Organic systems typically perform better than those with no labelling and Red tractor labelling, and that outdoor-bred and outdoor-finished systems perform better than indoor-bred and slatted-finished systems, respectively. We conclude that if our goal is to identify relatively better and worse farming systems for animal welfare, exactly how LCA welfare metrics are constructed may be less important than commonly perceived.

A global evaluation of the effectiveness of voluntary REDD+ projects at reducing deforestation and degradation in the moist tropics.

Reducing emissions from deforestation and forest degradation (REDD+) projects aim to contribute to climate change mitigation by protecting and enhancing carbon stocks in tropical forests, but there have been no systematic global evaluations of their impact. We used a new data set for tropical humid forests and a standardized evaluation approach (based on pixel matching) to quantify the performance of a representative sample of 40 voluntary REDD+ projects in 9 countries certified under the Verified Carbon Standard (VCS). In the first 5 years of implementation, deforestation within project areas was reduced by 47% (95% confidence interval [CI]: 24-68) compared with matched counterfactual pixels, and degradation rates were 58% lower (95% CI: 49-63). Reductions were small in absolute terms but greater in sites located in high-deforestation settings and did not appear to be substantially undermined by leakage activities in forested areas within 10 km of project boundaries. At the 26th Conference of the Parties of the United Nations Framework Convention on Climate Change, the international community renewed its commitment to tackling tropical deforestation as a nature-based solution to climate change. Our results indicate that incentivizing forest conservation through voluntary site-based projects can slow tropical deforestation and highlight the particular importance of prioritizing financing for areas at greater risk of deforestation.

Evaluación Global de la Efectividad de proyectos REDD+ en la Reducción de la Deforestación y Degradación en el Trópico Húmedo Resumen Los proyectos para la reducción de emisiones derivados de la deforestación y degradación de bosques (REDD+) tienen como meta contribuir a la mitigación del cambio climático al protejer y  fomentar la disponibilidad de carbono en bosques tropicales, pero a la fecha no se han realizado evaluaciones globales sistemáticas sobre su impacto. Utilizamos bases de datos recientes sobre bosques tropicales húmedos y un método estandarizado de evaluación (basado en 'emparejamiento' [matching] de pixeles) para cuantificar el desempeño de una muestra representativa de 40 proyectos voluntarios REDD+ , localizados en 9 países y certificados bajo el estándar Verified Carbon Standard (VCS). En los primeros 5 años de implementación, la deforestación en las áreas de los proyectos disminuyó en 47% (IC 95% 24-68) en comparación con los pixeles contrafactuales correspondientes, y las tasas de degradación fueron 58% menos (IC 95% 49-63). Las reducciones fueron pequeñas en términos absolutos pero mayores en sitios con tasas de deforestación elevadas, y no parecieron ser afectadas sustancialmente por efectos de fuga (leakage) en áreas boscosas en un radio de 10 km de los límites del proyecto. En la COP26, la comunidad internacional renovó su compromiso de afrontar la deforestación tropical como una solución al cambio climático basada en la naturaleza. Nuestros resultados indican que incentivar la conservación de bosques mediante proyectos locales voluntarios puede disminuir la deforestación tropical, y resaltan la importancia de priorizar financiamiento en áreas con un mayor riesgo de deforestación.

A global-level assessment of the effectiveness of protected areas at resisting anthropogenic pressures.

One-sixth of the global terrestrial surface now falls within protected areas (PAs), making it essential to understand how far they mitigate the increasing pressures on nature which characterize the Anthropocene. In by far the largest analysis of this question to date and not restricted to forested PAs, we compiled data from 12,315 PAs across 152 countries to investigate their ability to reduce human pressure and how this varies with socioeconomic and management circumstances. While many PAs show positive outcomes, strikingly we find that compared with matched unprotected areas, PAs have on average not reduced a compound index of pressure change over the past 15 y. Moreover, in tropical regions average pressure change from cropland conversion has increased inside PAs even more than in matched unprotected areas. However, our results also confirm previous studies restricted to forest PAs, where pressures are increasing, but less than in counterfactual areas. Our results also show that countries with high national-level development scores have experienced lower rates of pressure increase over the past 15 y within their PAs compared with a matched outside area. Our results caution against the rapid establishment of new PAs without simultaneously addressing the conditions needed to enable their success.

Impact of increasing vegetarian availability on meal selection and sales in cafeterias.

Shifting people in higher income countries toward more plant-based diets would protect the natural environment and improve population health. Research in other domains suggests altering the physical environments in which people make decisions ("nudging") holds promise for achieving socially desirable behavior change. Here, we examine the impact of attempting to nudge meal selection by increasing the proportion of vegetarian meals offered in a year-long large-scale series of observational and experimental field studies. Anonymized individual-level data from 94,644 meals purchased in 2017 were collected from 3 cafeterias at an English university. Doubling the proportion of vegetarian meals available from 25 to 50% (e.g., from 1 in 4 to 2 in 4 options) increased vegetarian meal sales (and decreased meat meal sales) by 14.9 and 14.5 percentage points in the observational study (2 cafeterias) and by 7.8 percentage points in the experimental study (1 cafeteria), equivalent to proportional increases in vegetarian meal sales of 61.8%, 78.8%, and 40.8%, respectively. Linking sales data to participants' previous meal purchases revealed that the largest effects were found in the quartile of diners with the lowest prior levels of vegetarian meal selection. Moreover, serving more vegetarian options had little impact on overall sales and did not lead to detectable rebound effects: Vegetarian sales were not lower at other mealtimes. These results provide robust evidence to support the potential for simple changes to catering practices to make an important contribution to achieving more sustainable diets at the population level.

Linking global drivers of agricultural trade to on-the-ground impacts on biodiversity.

Consumption of globally traded agricultural commodities like soy and palm oil is one of the primary causes of deforestation and biodiversity loss in some of the world's most species-rich ecosystems. However, the complexity of global supply chains has confounded efforts to reduce impacts. Companies and governments with sustainability commitments struggle to understand their own sourcing patterns, while the activities of more unscrupulous actors are conveniently masked by the opacity of global trade. We combine state-of-the-art material flow, economic trade, and biodiversity impact models to produce an innovative approach for understanding the impacts of trade on biodiversity loss and the roles of remote markets and actors. We do this for the production of soy in the Brazilian Cerrado, home to more than 5% of the world´s species. Distinct sourcing patterns of consumer countries and trading companies result in substantially different impacts on endemic species. Connections between individual buyers and specific hot spots explain the disproportionate impacts of some actors on endemic species and individual threatened species, such as the particular impact of European Union consumers on the recent habitat losses for the iconic giant anteater (Myrmecophaga tridactyla). In making these linkages explicit, our approach enables commodity buyers and investors to target their efforts much more closely to improve the sustainability of their supply chains in their sourcing regions while also transforming our ability to monitor the impact of such commitments over time.

Bayesian Skyline Plots disagree with range size changes based on Species Distribution Models for Holarctic birds.

During the Quaternary, large climate oscillations impacted the distribution and demography of species globally. Two approaches have played a major role in reconstructing changes through time: Bayesian Skyline Plots (BSPs), which reconstruct population fluctuations based on genetic data, and Species Distribution Models (SDMs), which allow us to back-cast the range occupied by a species based on its climatic preferences. In this paper, we contrast these two approaches by applying them to a large data set of 102 Holarctic bird species, for which both mitochondrial DNA sequences and distribution maps are available, to reconstruct their dynamics since the Last Glacial Maximum (LGM). Most species experienced an increase in effective population size (Ne , as estimated by BSPs) as well as an increase in geographical range (as reconstructed by SDMs) since the LGM; however, we found no correlation between the magnitude of changes in Ne and range size. The only clear signal we could detect was a later and greater increase in Ne for wetland birds compared to species that live in other habitats, a probable consequence of a delayed and more extensive increase in the extent of this habitat type after the LGM. The lack of correlation between SDM and BSP reconstructions could not be reconciled even when range shifts were considered. We suggest that this pattern might be linked to changes in population densities, which can be independent of range changes, and caution that interpreting either SDMs or BSPs independently is problematic and potentially misleading.

The scale of Nigeria's involvement in the trans-national illegal pangolin trade: Temporal and spatial patterns and the effectiveness of wildlife trade regulations.

The Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) prohibits commercial trans-national trade in pangolin specimens. However, African pangolins are continually trafficked to Asia for traditional medicine, with Nigeria considered a key hub. Using reported Nigeria-linked pangolin seizure data and interviews with Nigerian law enforcement officials, we a) characterised Nigeria's involvement in global pangolin trafficking January 2010-September 2021, particularly observing trafficking trends after pangolin's CITES Appendix I listing; b) estimated the minimum number of pangolins whose scales are in Nigeria-linked seizures January 2010-September 2021, and; c) assessed ongoing efforts within Nigeria to curb pangolin trafficking. Nigeria-linked seizures involved 190,407 kg of pangolin derivatives (99.9% scales) from a minimum of 799,343 pangolins (95% confidence interval; 625,944-996,353) of four species (see caveats in Methods). All shipments confiscated in transit were destined for Asia, with a rapid increase in the mass of maritime shipments over time. Furthermore, stockpiling of pangolin derivatives for overseas shipment is perhaps a prominent trafficking model in Nigeria. Nigeria's law enforcement efforts improved from 2017, the same year Nigeria apparently began playing a hub role. The impact of pangolin's CITES Appendix I listing on pangolin trafficking was unclear, as the marked rise in seizures from 2017 when the listing became effective, coincided with improvements in Nigerian law enforcement efforts. COVID-19-induced travel restrictions likely reduced trafficking activities in 2020 but activities may have fully resumed in 2021. This study provides new information to inform effective enforcement and policy formulation efforts to protect African pangolins.

A global strategy for road building.

The number and extent of roads will expand dramatically this century. Globally, at least 25 million kilometres of new roads are anticipated by 2050; a 60% increase in the total length of roads over that in 2010. Nine-tenths of all road construction is expected to occur in developing nations, including many regions that sustain exceptional biodiversity and vital ecosystem services. Roads penetrating into wilderness or frontier areas are a major proximate driver of habitat loss and fragmentation, wildfires, overhunting and other environmental degradation, often with irreversible impacts on ecosystems. Unfortunately, much road proliferation is chaotic or poorly planned, and the rate of expansion is so great that it often overwhelms the capacity of environmental planners and managers. Here we present a global scheme for prioritizing road building. This large-scale zoning plan seeks to limit the environmental costs of road expansion while maximizing its benefits for human development, by helping to increase agricultural production, which is an urgent priority given that global food demand could double by mid-century. Our analysis identifies areas with high environmental values where future road building should be avoided if possible, areas where strategic road improvements could promote agricultural development with relatively modest environmental costs, and 'conflict areas' where road building could have sizeable benefits for agriculture but with serious environmental damage. Our plan provides a template for proactively zoning and prioritizing roads during the most explosive era of road expansion in human history.

Land sparing to make space for species dependent on natural habitats and high nature value farmland.

Empirical evidence from four continents indicates that human food demand may be best reconciled with biodiversity conservation through sparing natural habitats by boosting agricultural yields. This runs counter to the conservation paradigm of wildlife-friendly farming, which is influential in Europe, where many species are dependent on low-yielding high nature value farmland threatened by both intensification and abandonment. In the first multi-taxon population-level test of land-sparing theory in Europe, we quantified how population densities of 175 bird and sedge species varied with farm yield across 26 squares (each with an area of 1 km2) in eastern Poland. We discovered that, as in previous studies elsewhere, simple land sparing, with only natural habitats on spared land, markedly out-performed land sharing in its effect on region-wide projected population sizes. However, a novel 'three-compartment' land-sparing approach, in which about one-third of spared land is assigned to very low-yield agriculture and the remainder to natural habitats, resulted in least-reduced projected future populations for more species. Implementing the three-compartment model would require significant reorganization of current subsidy regimes, but would mean high-yield farming could release sufficient land for species dependent on both natural and high nature value farmland to persist.

Getting Road Expansion on the Right Track: A Framework for Smart Infrastructure Planning in the Mekong.

The current unprecedented expansion of infrastructure promises to enhance human wellbeing but risks causing substantial harm to natural ecosystems and the benefits they provide for people. A framework for systematically and proactively identifying the likely benefits and costs of such developments is badly needed. Here, we develop and test at the subregional scale a recently proposed global scheme for comparing the potential gains from new roads for food production with their likely impact on biodiversity and ecosystem services. Working in the Greater Mekong-an exceptionally biodiverse subregion undergoing rapid development-we combined maps of isolation from urban centres, yield gaps, and the current area under 17 crops to estimate where and how far road development could in principle help to increase food production without the need for cropland expansion. We overlaid this information with maps summarising the importance of remaining habitats to terrestrial vertebrates and (as examples of major ecosystem services) to global and local climate regulation. This intersection revealed several largely converted yet relatively low-yielding areas (such as central, eastern, and northeastern Thailand and the Ayeyarwady Delta), where narrowing yield gaps by improving transport links has the potential to substantially increase food production at relatively limited environmental cost. Concentrating new roads and road improvements here while taking strong measures to prevent their spread into areas which are still extensively forested (such as northern Laos, western Yunnan, and southwestern Cambodia) could thus enhance rural livelihoods and regional food production while helping safeguard vital ecosystem services and globally significant biological diversity.

Bird conservation and the land sharing-sparing continuum in farmland-dominated landscapes of lowland England.

Empirical evidence from many regions suggests that most species would be least negatively affected if human food demand were met through high-yield agricultural production and conservation of nonfarm ecosystems (land sparing), rather than through wildlife-friendly farming over a larger area (land sharing). However, repeated glaciation and a long history of agriculture may lead to different results in regions such as western Europe. We compared the consequences of land sparing and land sharing on breeding bird species in 2 lowland regions of England, The Fens, with 101 species, and Salisbury Plain, with 83. We derived density-yield responses for each species and then estimated regional population size under regional food production strategies, including land sharing and land sparing, a range of intermediate strategies, and a novel mixed strategy. In both regions, more species achieved maximum regional population size under land sparing than land sharing. In The Fens, the majority of birds were loser species (estimated to have smaller populations under all food production strategies than in the preagricultural baseline scenario), whereas in Salisbury Plain the majority were winners (smaller populations in the preagricultural baseline scenario). Loser species overwhelmingly achieved maximum regional population size under land sparing, whereas winner species achieved maximum regional population size under either land sharing or an intermediate strategy, highlighting the importance of defining which groups of species are the target of conservation. A novel 3-compartment strategy (combining high-yield farming, natural habitat, and low-yield farming) often performed better than either land sharing or land sparing. Our results support intermediate or 3-compartment land-sparing strategies to maximize bird populations across lowland agricultural landscapes. To deliver conservation outcomes, any shift toward land sparing must, however, ensure yield increases are sustainable in the long term, do not entail increased negative effects on surrounding areas, and are linked to allocation of land for nature.

Conservación de Aves y el Continuo de Suelo Compartido-Reservado en Paisajes Dominados por Tierras de Cultivo en las Tierras Bajas de Inglaterra Resumen La evidencia empírica proveniente de muchas regiones sugiere que la mayoría de las especies se verían menos afectadas negativamente si se cumpliera con la demanda humana de alimentos por medio de una producción agrícola de alto rendimiento y la conservación de ecosistemas no agrícolas (dosificación de suelo) en lugar de hacerlo a través de la agricultura amigable con la fauna en un área mayor (partición de suelo). Sin embargo, la glaciación repetitiva y una larga historia agrícola podrían brindar diferentes resultados en regiones como Europa occidental. Comparamos las consecuencias de la dosificación y la partición de suelo sobre especies de aves en reproducción en dos regiones de tierras bajas en Inglaterra: Los Fens, con 101 especies, y la Planicie Salisbury, con 83 especies. Derivamos las respuestas con densidad de rendimiento para cada especie y después estimamos el tamaño poblacional regional bajo estrategias regionales de producción de alimentos, incluyendo la dosificación y la partición de suelo, una gama de estrategias intermedias y una novedosa estrategia mixta. En ambas regiones, más especies alcanzaron el tamaño poblacional máximo para la región bajo la dosificación del suelo que bajo la partición del suelo. En Los Fens, la mayoría de las aves fueron especies perdedoras (se estimó que tendrían tamaños poblacionales menores bajo todas las estrategias de producción de alimento que en el escenario pre-agrícola de la línea base) mientras que en la Planicie Salisbury, la mayoría de las especies fueron ganadoras (con poblaciones más pequeñas en el escenario pre-agrícola de la línea base). Las especies perdedoras tuvieron abrumadoramente un tamaño poblacional máximo para la región bajo la dosificación de suelo, mientras que las especies ganadoras tuvieron este máximo poblacional bajo la partición de suelo o alguna estrategia intermedia, lo que resalta la importancia de la definición de cuáles grupos de especies son el objetivo de conservación. Una estrategia novedosa de tres compartimentos (combina la agricultura de alto rendimiento, el hábitat natural y la agricultura de bajo rendimiento) muchas veces tuvo un mejor desempeño que la dosificación o la partición del suelo. Nuestros resultados respaldan a las estrategias de dosificación de suelo intermedias o de tres compartimentos para maximizar las poblaciones de aves en todos los paisajes agrícolas de las tierras bajas. Para brindar resultados de conservación, cualquier cambio hacia la dosificación del suelo, sin embargo, debe asegurar que los incrementos en el rendimiento son sustentables a largo plazo, no conllevan un incremento de efectos negativos en las áreas circundantes, y que están vinculados a la asignación de suelo para la naturaleza.

Walk on the wild side: estimating the global magnitude of visits to protected areas.

How often do people visit the world's protected areas (PAs)? Despite PAs covering one-eighth of the land and being a major focus of nature-based recreation and tourism, we don't know. To address this, we compiled a globally-representative database of visits to PAs and built region-specific models predicting visit rates from PA size, local population size, remoteness, natural attractiveness, and national income. Applying these models to all but the very smallest of the world's terrestrial PAs suggests that together they receive roughly 8 billion (8 x 109) visits/y-of which more than 80% are in Europe and North America. Linking our region-specific visit estimates to valuation studies indicates that these visits generate approximately US $600 billion/y in direct in-country expenditure and US $250 billion/y in consumer surplus. These figures dwarf current, typically inadequate spending on conserving PAs. Thus, even without considering the many other ecosystem services that PAs provide to people, our findings underscore calls for greatly increased investment in their conservation.