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.

Evaluating and expanding the European Union's protected-area network toward potential post-2020 coverage targets.

The Convention on Biological Diversity's (CBD) strategic plan will expire in 2020, but biodiversity loss is ongoing. Scientists call for more ambitious targets in the next agreement. The nature-needs-half movement, for example, has advocated conserving half of Earth to solve the biodiversity crisis, which has been translated to protecting 50% of each ecoregion. We evaluated current protection levels of ecoregions in the territory of one of the CBD's signatories, the European Union (EU). We also explored the possible enlargement of the Natura 2000 network to implement 30% or 50% ecoregion coverage in the EU member states' protected area (PA) network. Based on the most recent land-use data, we examined whether ecoregions have enough natural area left to reach such high coverage targets. We used a spatially explicit mixed integer programing model to estimate the least-cost expansion of the PA network based on 3 scenarios that put different emphasis on total conservation cost, ecological representation of ecosystems, or emphasize an equal share of the burden among member states. To realize 30% and 50% ecoregion coverage, the EU would need to add 6.6% and 24.2%, respectively, of its terrestrial area to its PA network. For all 3 scenarios, the EU would need to designate most recommended new PAs in seminatural forests and other semi- or natural ecosystems. Because 15 ecoregions did not have enough natural area left to implement the ecoregion-coverage targets, some member states would also need to establish new PAs on productive land, allocating the largest share to arable land. Thirty percent ecoregion coverage was met by protecting remaining natural areas in all ecoregions except 3, where productive land would also need to be included. Our results support discussions of higher ecoregions protection targets for post-2020 biodiversity frameworks.

Evaluación y Expansión de la Red de Áreas Protegidas de la Unión Europea hacia Objetivos Potenciales de Cobertura Post 2020 Resumen El plan estratégico del Convenio sobre la Diversidad Biológica (CBD) expirará en 2020, pero la pérdida de la biodiversidad continúa. Los científicos exigen objetivos más ambiciosos para el siguiente acuerdo. Por ejemplo, la corriente la-naturaleza-necesita-la-mitad ha abogado por la conservación de la mitad del planeta para resolver la crisis de la biodiversidad, lo que se ha traducido a la protección del 50% de cada ecoregión. Evaluamos los niveles actuales de protección de las ecoregiones en el territorio de uno de los signatarios de la CBD, la Unión Europea (UE). También exploramos el posible crecimiento de la red Natura 2000 para implementar una cobertura del 30% o 50% de las ecoregiones en la red de áreas protegidas (AP) de los estados miembros de la UE. Con base en los datos más recientes de uso de suelo, examinamos si las ecoregiones todavía tienen suficiente área natural como para alcanzar tales objetivos tan altos de cobertura. Usamos un modelo de programación entera mixta espacialmente explícito para estimar la expansión más asequible de la red de AP con base en tres escenarios que colocan un énfasis diferente sobre el costo total de la conservación, la representación ecológica de los ecosistemas o que enfaticen un porcentaje equitativo de la carga entre los estados miembros. Para alcanzar una cobertura del 30% y 50% de las ecoregiones, la UE necesitaría añadir 6.6% y 24.2%, respectivamente, de su área terrestre a la red de AP. Para los tres escenarios, la UE necesitaría designar la mayoría de las nuevas AP recomendadas en bosques seminaturales y en otros ecosistemas semi- o totalmente naturales. Debido a que 15 ecoregiones no tenían ya suficiente área natural para implementar los objetivos de cobertura de ecoregiones, algunos estados miembros también necesitarían establecer nuevas AP en suelo productivo, asignando la proporción mayor al suelo arable. La cobertura del 30% de las ecoregiones se alcanzó con la protección de las áreas naturales permanecientes en todas las ecoregiones salvo tres, en donde el suelo productivo también necesitaría estar incluido. Nuestros resultados respaldan las discusiones sobre objetivos más altos de protección de ecoregiones para los marcos de trabajo post 2020 para la biodiversidad.

Managing the middle: A shift in conservation priorities based on the global human modification gradient.

An increasing number of international initiatives aim to reconcile development with conservation. Crucial to successful implementation of these initiatives is a comprehensive understanding of the current ecological condition of landscapes and their spatial distributions. Here, we provide a cumulative measure of human modification of terrestrial lands based on modeling the physical extents of 13 anthropogenic stressors and their estimated impacts using spatially explicit global datasets with a median year of 2016. We quantified the degree of land modification and the amount and spatial configuration of low modified lands (i.e., natural areas relatively free from human alteration) across all ecoregions and biomes. We identified that fewer unmodified lands remain than previously reported and that most of the world is in a state of intermediate modification, with 52% of ecoregions classified as moderately modified. Given that these moderately modified ecoregions fall within critical land use thresholds, we propose that they warrant elevated attention and require proactive spatial planning to maintain biodiversity and ecosystem function before important environmental values are lost.

Identifying conservation priorities for threatened Eastern Himalayan mammals.

To augment mammal conservation in the Eastern Himalayan region, we assessed the resident 255 terrestrial mammal species and identified the 50 most threatened species based on conservation status, endemism, range size, and evolutionary distinctiveness. By using the spatial analysis package letsR and the complementarity core-area method in the conservation planning software Zonation, we assessed the current efficacy of their protection and identified priority conservation areas by comparing protected areas (PAs), land cover, and global ecoregion 2017 maps at a 100 × 100 m spatial scale. The 50 species that were most threatened, geographically restricted, and evolutionarily distinct faced a greater extinction risk than globally nonthreatened and wide-ranging species and species with several close relatives. Small, medium-sized, and data-deficient species faced extinction from inadequate protection in PAs relative to wide-ranging charismatic species. There was a mismatch between current PA distribution and priority areas for conservation of the 50 most endangered species. To protect these species, the skewed regional PA distribution would require expansion. Where possible, new PAs and transboundary reserves in the 35 priority areas we identified should be established. There are adequate remaining natural areas in which to expand current Eastern Himalayan PAs. Consolidation and expansion of PAs in the EH requires strengthening national and regional transboundary collaboration, formulating comprehensive regional land-use plans, diversifying conservation funding, and enhancing information sharing through a consolidated regional database.

Wild, connected, and diverse: building a more resilient system of protected areas.

Current systems of conservation reserves may be insufficient to sustain biodiversity in the face of climate change and habitat losses. Consequently, calls have been made to protect Earth's remaining wildlands and complete the system of protected areas by establishing conservation reserves that (1) better represent ecosystems, (2) increase connectivity to facilitate biota movement in response to stressors including climate change, and (3) promote species persistence within intact landscapes. Using geospatial data, we conducted an assessment for expanding protected areas within the contiguous United States to include the least human-modified wildlands, establish a connected network, and better represent ecosystem diversity and hotspots of biodiversity. Our composite map highlights areas of high value to achieve these goals in the western United States, where existing protected areas and lands with high ecological integrity are concentrated. We also identified important areas in the East rich in species and containing ecosystems that are poorly represented in the existing protected area system. Expanding protection to these priority areas is ultimately expected to create a more resilient system for protecting the nation's biological heritage. This expectation should be subject to rigorous testing prior to implementation, and regional monitoring will ensure areas and actions are adjusted over time.