Land-use and climate risk assessment for Earth's remaining wilderness.

Earth's wilderness areas are reservoirs of genetic information and carbon storage systems, and are vital to reducing extinction risks. Retaining the conservation value of these areas is fundamental to achieving global biodiversity conservation goals; however, climate and land-use risk can undermine their ability to provide these functions. The extent to which wilderness areas are likely to be impacted by these drivers has not previously been quantified. Using climate and land-use change during baseline (1971-2005) and future (2016-2050) periods, we estimate that these stressors within wilderness areas will increase by ca. 60% and 39%, respectively, under a scenario of high emission and land-use change (SSP5-RCP8.5). Nearly half (49%) of all wilderness areas could experience substantial climate change by 2050 under this scenario, potentially limiting their capacity to shelter biodiversity. Notable climate (>5 km year-1) and land-use (>0.25 km year-1) changes are expected to occur more rapidly in the unprotected wilderness, including the edges of the Amazonian wilderness, Northern Russia, and Central Africa, which support unique assemblages of species and are critical for the preservation of biodiversity. However, an alternative scenario of sustainable development (SSP1-RCP2.6) would attenuate the projected climate velocity and land-use instability by 54% and 6%, respectively. Mitigating greenhouse gas emissions and preserving the remaining intact natural ecosystems can help fortify these bastions of biodiversity.

Humid tropical vertebrates are at lower risk of extinction and population decline in forests with higher structural integrity.

Reducing deforestation underpins global biodiversity conservation efforts. However, this focus on retaining forest cover overlooks the multitude of anthropogenic pressures that can degrade forest quality and imperil biodiversity. We use remotely sensed indices of tropical rainforest structural condition and associated human pressures to quantify the relative importance of forest cover, structural condition and integrity (the cumulative effect of condition and pressures) on vertebrate species extinction risk and population trends across the global humid tropics. We found that tropical rainforests of high integrity (structurally intact and under low pressures) were associated with lower likelihood of species being threatened and having declining populations, compared with forest cover alone (without consideration of condition and pressures). Further, species were more likely to be threatened or have declining populations if their geographic ranges contained high proportions of degraded forest than if their ranges contained lower proportions of forest cover but of high quality. Our work suggests that biodiversity conservation policies to preserve forest integrity are now urgently required alongside ongoing efforts to halt deforestation in the hyperdiverse humid tropics.

Tropical forests are home to over half of the world's vertebrate species.

Tropical forests are renowned for their astonishing diversity of life, but the fundamental question of how many species occur in tropical forests remains unanswered. Using geographic range maps and data on species habitat associations, we determined that tropical forests harbor 62% of global terrestrial vertebrate species, more than twice the number found in any other terrestrial biome on Earth. Up to 29% of global vertebrate species are endemic to tropical forests, with more than 20% of these species at risk of extinction. Humid tropical forests (also known as tropical rainforests) and the Neotropics dominate as centers of species diversity, harboring more than 90% and nearly half of all tropical forest vertebrates, respectively. To maintain the biodiversity that underpins the ecosystem functions and services essential for human well-being, we emphasize the critical importance of environmental policies aimed at reducing tropical deforestation and mitigating deleterious anthropogenic pressures on these imperiled ecosystems.

Matrix condition mediates the effects of habitat fragmentation on species extinction risk.

Habitat loss is the leading cause of the global decline in biodiversity, but the influence of human pressure within the matrix surrounding habitat fragments remains poorly understood. Here, we measure the relationship between fragmentation (the degree of fragmentation and the degree of patch isolation), matrix condition (measured as the extent of high human footprint levels), and the change in extinction risk of 4,426 terrestrial mammals. We find that the degree of fragmentation is strongly associated with changes in extinction risk, with higher predictive importance than life-history traits and human pressure variables. Importantly, we discover that fragmentation and the matrix condition are stronger predictors of risk than habitat loss and habitat amount. Moreover, the importance of fragmentation increases with an increasing deterioration of the matrix condition. These findings suggest that restoration of the habitat matrix may be an important conservation action for mitigating the negative effects of fragmentation on biodiversity.

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.

Wilderness forms and their implications for global environmental policy and conservation.

With the intention of securing industry-free land and seascapes, protecting wilderness entered international policy as a formal target for the first time in the zero draft of the Post-2020 Global Biodiversity Framework under the Convention on Biological Diversity. Given this increased prominence in international policy, it is timely to consider the extent to which the construct of wilderness supports global conservation objectives. We evaluated the construct by overlaying recently updated cumulative human pressure maps that offer a global-scale delineation of industry-free land as wilderness with maps of carbon stock, species richness, and ground travel time from urban centers. Wilderness areas took variable forms in relation to carbon stock, species richness, and proximity to urban centers, where 10% of wilderness areas represented high carbon and species richness, 20% low carbon and species richness, and 3% high levels of remoteness (>48 h), carbon, and species richness. Approximately 35% of all remaining wilderness in 2013 was accessible in <24 h of travel time from urban centers. Although the construct of wilderness can be used to secure benefits in specific contexts, its application in conservation must account for contextual and social implications. The diverse characterization of wilderness under a global environmental conservation lens shows that a nuanced framing and application of the construct is needed to improve understanding, communication, and retention of its variable forms as industry-free places.

Formas de las Áreas Silvestres y sus Implicaciones para las Políticas y la Conservación Mundial Resumen Con la intención de asegurar paisajes terrestres y marinos libres de la industria, la protección de las áreas silvestres entró a la política internacional por primera vez como un objetivo formal en el primer borrador del Marco de Trabajo para la Biodiversidad Mundial Post-2020 bajo el Convenio sobre la Diversidad Biológica. Con este incremento en la presencia dentro de la política internacional, es oportuno considerar el grado al que el concepto de área silvestre ayuda a los objetivos de conservación mundial. Evaluamos este concepto mediante la superposición de mapas de la presión humana acumulada recientemente actualizados que brindan una definición a escala mundial de las tierras libres de industria con mapas del stock de carbono, riqueza de especies y el tiempo de traslado terrestre desde los centros urbanos. Las áreas silvestres mostraron formas variables con respecto al stock de carbono, la riqueza de especies y la cercanía a los centros urbanos, de las cuales el 10% representó una elevada riqueza de especies y presencia de carbono, el 20% una baja riqueza de especies y presencia de carbono y el 3% una elevada lejanía (>48 horas), presencia de carbono y riqueza de especies. Aproximadamente el 35% de todas las áreas silvestres en 2013 era accesible en <24 horas de traslado desde los centros urbanos. Aunque el concepto de áreas silvestres puede usarse para garantizar beneficios en contextos específicos, su aplicación en la conservación debe considerar las implicaciones contextuales y sociales. La caracterización diversa de las áreas silvestres bajo el lente de la conservación ambiental mundial muestra que un encuadre matizado y la aplicación de este concepto son necesarios para aumentar el conocimiento, la comunicación y la retención de sus formas variables como lugares libres de industria.

Wilderness.

James Watson and Oscar Venter introduce the concept of wilderness and its role in conservation efforts.

The importance of Indigenous Peoples' lands for the conservation of terrestrial mammals.

Indigenous Peoples' lands cover over one-quarter of Earth's surface, a significant proportion of which is still free from industrial-level human impacts. As a result, Indigenous Peoples and their lands are crucial for the long-term persistence of Earth's biodiversity and ecosystem services. Yet, information on species composition on these lands globally remains largely unknown. We conducted the first comprehensive analysis of terrestrial mammal composition across mapped Indigenous lands based on data on area of habitat (AOH) for 4460 mammal species assessed by the International Union for Conservation of Nature. We overlaid each species' AOH on a current map of Indigenous lands and found that 2695 species (60% of assessed mammals) had ≥10% of their ranges on Indigenous Peoples' lands and 1009 species (23%) had >50% of their ranges on these lands. For threatened species, 473 (47%) occurred on Indigenous lands with 26% having >50% of their habitat on these lands. We also found that 935 mammal species (131 categorized as threatened) had ≥ 10% of their range on Indigenous Peoples' lands that had low human pressure. Our results show how important Indigenous Peoples' lands are to the successful implementation of conservation and sustainable development agendas worldwide.

La Importancia de las Tierras de los Pueblos Indígenas para la Conservación de los Mamíferos Terrestres Resumen Las tierras pertenecientes a pueblos indígenas cubren más de un cuarto de la superficie del planeta, una proporción importante que se encuentra aún libre de impactos humanos a nivel industrial. Como resultado, los pueblos indígenas y sus tierras son cruciales para la persistencia a largo plazo de la biodiversidad en la Tierra y de los servicios ecosistemicos. Sin embargo, la información sobre la composición de especies en estas tierras a nivel mundial todavía permanece desconocida en su mayoría. Realizamos el primer análisis integral de la composición de mamíferos terrestres a lo largo de las tierras indígenas mapeadas con base en los datos sobre el área del hábitat (ADH) de 4,460 especies de mamíferos valorados por la Unión Internacional para la Conservación de la Naturaleza. Sobrepusimos el ADH de cada especie en un mapa actual de tierras indígenas y encontramos que 2,695 especies (60% de los mamíferos valorados) tienen ≥10% de su distribución dentro de tierras de pueblos indígenas y que 1,009 especies (23%) tienen >50% de su distribución dentro de estas tierras. De las especies amenazadas, 473 (47%) ocurrieron en tierras indígenas.También descubrimos que 935 especies de mamíferos (131 categorizadas como amenazadas) tienen ≥ 10% de su distribución dentro de tierras de pueblos indígenas con baja presión humana. Nuestros resultados muestran cuán importantes son las tierras de los pueblos indígenas para la implementación exitosa de la conservación y las agendas globales de desarrollo sustentable.

Author Correction: Area-based conservation in the twenty-first century.

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

Area-based conservation in the twenty-first century.

Humanity will soon define a new era for nature-one that seeks to transform decades of underwhelming responses to the global biodiversity crisis. Area-based conservation efforts, which include both protected areas and other effective area-based conservation measures, are likely to extend and diversify. However, persistent shortfalls in ecological representation and management effectiveness diminish the potential role of area-based conservation in stemming biodiversity loss. Here we show how the expansion of protected areas by national governments since 2010 has had limited success in increasing the coverage across different elements of biodiversity (ecoregions, 12,056 threatened species, 'Key Biodiversity Areas' and wilderness areas) and ecosystem services (productive fisheries, and carbon services on land and sea). To be more successful after 2020, area-based conservation must contribute more effectively to meeting global biodiversity goals-ranging from preventing extinctions to retaining the most-intact ecosystems-and must better collaborate with the many Indigenous peoples, community groups and private initiatives that are central to the successful conservation of biodiversity. The long-term success of area-based conservation requires parties to the Convention on Biological Diversity to secure adequate financing, plan for climate change and make biodiversity conservation a far stronger part of land, water and sea management policies.

Just ten percent of the global terrestrial protected area network is structurally connected via intact land.

Land free of direct anthropogenic disturbance is considered essential for achieving biodiversity conservation outcomes but is rapidly eroding. In response, many nations are increasing their protected area (PA) estates, but little consideration is given to the context of the surrounding landscape. This is despite the fact that structural connectivity between PAs is critical in a changing climate and mandated by international conservation targets. Using a high-resolution assessment of human pressure, we show that while ~40% of the terrestrial planet is intact, only 9.7% of Earth's terrestrial protected network can be considered structurally connected. On average, 11% of each country or territory's PA estate can be considered connected. As the global community commits to bolder action on abating biodiversity loss, placement of future PAs will be critical, as will an increased focus on landscape-scale habitat retention and restoration efforts to ensure those important areas set aside for conservation outcomes will remain (or become) connected.

A policy-driven framework for conserving the best of Earth's remaining moist tropical forests.

Tropical forests vary in composition, structure and function such that not all forests have similar ecological value. This variability is caused by natural and anthropogenic disturbance regimes, which influence the ability of forests to support biodiversity, store carbon, mediate water yield and facilitate human well-being. While international environmental agreements mandate protecting and restoring forests, only forest extent is typically considered, while forest quality is ignored. Consequently, the locations and loss rates of forests of high ecological value are unknown and coordinated strategies for conserving these forests remain undeveloped. Here, we map locations high in forest structural integrity as a measure of ecological quality on the basis of recently developed fine-resolution maps of three-dimensional forest structure, integrated with human pressure across the global moist tropics. Our analyses reveal that tall forests with closed canopies and low human pressure typical of natural conditions comprise half of the global humid or moist tropical forest estate, largely limited to the Amazon and Congo basins. Most of these forests have no formal protection and, given recent rates of loss, are at substantial risk. With the rapid disappearance of these 'best of the last' forests at stake, we provide a policy-driven framework for their conservation and restoration, and recommend locations to maintain protections, add new protections, mitigate deleterious human impacts and restore forest structure.

Global human influence maps reveal clear opportunities in conserving Earth's remaining intact terrestrial ecosystems.

Leading up to the Convention on Biological Diversity Conference of the Parties 15, there is momentum around setting bold conservation targets. Yet, it remains unclear how much of Earth's land area remains without significant human influence and where this land is located. We compare four recent global maps of human influences across Earth's land, Anthromes, Global Human Modification, Human Footprint and Low Impact Areas, to answer these questions. Despite using various methodologies and data, these different spatial assessments independently estimate similar percentages of the Earth's terrestrial surface as having very low (20%-34%) and low (48%-56%) human influence. Three out of four spatial assessments agree on 46% of the non-permanent ice- or snow-covered land as having low human influence. However, much of the very low and low influence portions of the planet are comprised of cold (e.g., boreal forests, montane grasslands and tundra) or arid (e.g., deserts) landscapes. Only four biomes (boreal forests, deserts, temperate coniferous forests and tundra) have a majority of datasets agreeing that at least half of their area has very low human influence. More concerning, <1% of temperate grasslands, tropical coniferous forests and tropical dry forests have very low human influence across most datasets, and tropical grasslands, mangroves and montane grasslands also have <1% of land identified as very low influence across all datasets. These findings suggest that about half of Earth's terrestrial surface has relatively low human influence and offers opportunities for proactive conservation actions to retain the last intact ecosystems on the planet. However, though the relative abundance of ecosystem areas with low human influence varies widely by biome, conserving these last intact areas should be a high priority before they are completely lost.

Reconciling global priorities for conserving biodiversity habitat.

Degradation and loss of natural habitat is the major driver of the current global biodiversity crisis. Most habitat conservation efforts to date have targeted small areas of highly threatened habitat, but emerging debate suggests that retaining large intact natural systems may be just as important. We reconcile these perspectives by integrating fine-resolution global data on habitat condition and species assemblage turnover to identify Earth's high-value biodiversity habitat. These are areas in better condition than most other locations predicted to have once supported a similar assemblage of species and are found within both intact regions and human-dominated landscapes. However, only 18.6% of this high-value habitat is currently protected globally. Averting permanent biodiversity loss requires clear, spatially explicit targets for retaining these unprotected high-value habitats.

Global opportunities and challenges for transboundary conservation.

Rapid biodiversity loss has prompted global action to prevent further declines, yet coordinated conservation action among nations remains elusive. As a result, species with ranges that span international borders-which include 53.8% of terrestrial birds, mammals and amphibians-are in increasing peril through uncoordinated management and artificial barriers to human movement, such as border fences. Transboundary conservation initiatives represent a unique opportunity to better protect species through coordinated management across national borders. Using metrics of governance, collaboration and human pressure, we provide an index of transboundary conservation feasibility to assess global opportunities and challenges for different nations. While the transboundary conservation potential of securing multinational threatened species varied substantially, there are distinct opportunities in South-East Asia, Northern Europe, North America and South America. But to successfully avert the loss of transboundary species, the global community must be prepared to invest in some regions facing greater implementation challenges, including the nations of Central Africa, where efforts may necessitate establishing rapid conservation interventions postconflict that align with local socio-cultural opportunities and constraints. Sanctioned and coordinated approaches towards managing transboundary species are now essential to prevent further declines of many endangered species, and global policy efforts must do more to produce and enact legitimate mechanisms for collaborative action in conservation.

Renewable energy development threatens many globally important biodiversity areas.

Transitioning from fossil fuels to renewable energy is fundamental for halting anthropogenic climate change. However, renewable energy facilities can be land-use intensive and impact conservation areas, and little attention has been given to whether the aggregated effect of energy transitions poses a substantial threat to global biodiversity. Here, we assess the extent of current and likely future renewable energy infrastructure associated with onshore wind, hydropower and solar photovoltaic generation, within three important conservation areas: protected areas (PAs), Key Biodiversity Areas (KBAs) and Earth's remaining wilderness. We identified 2,206 fully operational renewable energy facilities within the boundaries of these conservation areas, with another 922 facilities under development. Combined, these facilities span and are degrading 886 PAs, 749 KBAs and 40 distinct wilderness areas. Two trends are particularly concerning. First, while the majority of historical overlap occurs in Western Europe, the renewable electricity facilities under development increasingly overlap with conservation areas in Southeast Asia, a globally important region for biodiversity. Second, this next wave of renewable energy infrastructure represents a ~30% increase in the number of PAs and KBAs impacted and could increase the number of compromised wilderness areas by ~60%. If the world continues to rapidly transition towards renewable energy these areas will face increasing pressure to allow infrastructure expansion. Coordinated planning of renewable energy expansion and biodiversity conservation is essential to avoid conflicts that compromise their respective objectives.

The human footprint represents observable human pressures: Reply to Kennedy et al.

The Human Modification map differs in important ways from the map of the human footprint, such as its mapping of widespread direct modification of much of the world's polar regions. An extensive validation reveals large inaccuracies in the Human Modification map, and that the human footprint tends to better represent actual observable human pressures on the ground. This article is a commentary on Kennedy et al., 25, 811-826; See also the Commentary on this article by Kennedy et al., 26, 333-336.

Correction: Hotspots of human impact on threatened terrestrial vertebrates.

[This corrects the article DOI: 10.1371/journal.pbio.3000158.].