Perspectives on area-based conservation and its meaning for future biodiversity policy.

During 2021, Parties to the Convention on Biological Diversity (CBD) are expected to meet in Kunming, China, to agree on a new global biodiversity framework aimed at halting and reversing biodiversity loss, encouraging the sustainable use of biodiversity, and ensuring the equitable sharing of its benefits. As the post-2020 global biodiversity framework evolves, parties to the convention are being exposed to a range of perspectives on the conservation and sustainable use of biodiversity, relating to the future framework as a whole or to aspects of it. Area-based conservation measures are one such aspect, and there are diverse perspectives on how new targets might be framed in relation to these measures. These perspectives represent different outlooks on the relationship between human and nonhuman life on Earth. However, in most cases there is a lack of clarity on how they would be implemented in practice, the implications this would have for biodiversity and human well-being, and how they would contribute to achieving the 2050 Vision for Biodiversity of "living in harmony with nature." We sought to clarify these issues by summarizing some of these perspectives in relation to the future of area-based biodiversity conservation. We identified these perspectives through a review of the literature and expert consultation workshops and compiled them into 4 main groups: Aichi+, ambitious area-based conservation perspectives, new conservation, and whole-earth conservation. We found that although the perspectives Aichi+ and whole earth are in some cases at odds with one another, they also have commonalities, and all perspectives have elements that can contribute to developing and implementing the post-2020 global biodiversity framework and achieving the longer term CBD 2050 Vision.

Perspectivas de la Conservación Basada en el Área y su Significado para las Futuras Políticas de Biodiversidad Resumen Durante 2021, se espera que las partes miembro del Convenio sobre la Diversidad Biológica (CBD) se reúnan en Kunming, China, para acordar un nuevo marco de trabajo global para la biodiversidad enfocado en detener y revertir la pérdida de la biodiversidad, promover el uso sustentable de la biodiversidad y asegurar la repartición equitativa de sus beneficios. Conforme evoluciona el marco de trabajo global para la biodiversidad post-2020, las partes miembro del convenio están conociendo una gama de perspectivas de la conservación y el uso sustentable de la biodiversidad, relacionándolas con el futuro marco de trabajo en su totalidad o sólo con algunos aspectos del marco de trabajo. Las medidas de conservación basadas en el área son uno de dichos aspectos y existen diversas perspectivas sobre cómo los nuevos objetivos podrían estar enmarcados en relación a estas medidas. Estas perspectivas representan diferentes puntos de vista sobre la relación entre la vida humana y no humana en la Tierra. Sin embargo, en la mayoría de los casos existe una falta de claridad sobre cómo se implementarían en la práctica, las implicaciones que ésto tendría para la biodiversidad y el bienestar humano y cómo contribuirían para alcanzar la Visión para la Biodiversidad 2050 de "vivir en armonía con la naturaleza". Buscamos aclarar estos temas al resumir algunas de estas perspectivas en relación al futuro de la conservación de la biodiversidad basada en el área. Identificamos estas perspectivas por medio de una revisión de la literatura y talleres de consulta a expertos y las compilamos en cuatro grupos principales: Aichi+, perspectivas ambiciosas de conservación basada en el área, conservación nueva y conservación del mundo entero. Descubrimos que aunque las perspectivas Aichi+ y conservación del mundo entero entran en conflicto en algunos casos, también tienen puntos comunes, y todas las perspectivas tienen elementos que pueden contribuir al desarrollo e implementación del marco de trabajo global para la biodiversidad post-2020 y para alcanzar la Visión CBD 2050 de mayor plazo.

Mapping the planet's critical areas for biodiversity and nature's contributions to people.

Meeting global commitments to conservation, climate, and sustainable development requires consideration of synergies and tradeoffs among targets. We evaluate the spatial congruence of ecosystems providing globally high levels of nature's contributions to people, biodiversity, and areas with high development potential across several sectors. We find that conserving approximately half of global land area through protection or sustainable management could provide 90% of the current levels of ten of nature's contributions to people and meet minimum representation targets for 26,709 terrestrial vertebrate species. This finding supports recent commitments by national governments under the Global Biodiversity Framework to conserve at least 30% of global lands and waters, and proposals to conserve half of the Earth. More than one-third of areas required for conserving nature's contributions to people and species are also highly suitable for agriculture, renewable energy, oil and gas, mining, or urban expansion. This indicates potential conflicts among conservation, climate and development goals.

The Global Dam Watch database of river barrier and reservoir information for large-scale applications.

There are millions of river barriers worldwide, ranging from wooden locks to concrete dams, many of which form associated impoundments to store water in small ponds or large reservoirs. Besides their benefits, there is growing recognition of important environmental and social trade-offs related to these artificial structures. However, global datasets describing their characteristics and geographical distribution are often biased towards particular regions or specific applications, such as hydropower dams affecting fish migration, and are thus not globally consistent. Here, we present a new river barrier and reservoir database developed by the Global Dam Watch (GDW) consortium that integrates, harmonizes, and augments existing global datasets to support large-scale analyses. Data curation involved extensive quality control processes to create a single, globally consistent data repository of instream barriers and reservoirs that are co-registered to a digital river network. Version 1.0 of the GDW database contains 41,145 barrier locations and 35,295 associated reservoir polygons representing a cumulative storage capacity of 7,420 km3 and an artificial terrestrial surface water area of 304,600 km2.

Mapping the planet's critical natural assets.

Sustaining the organisms, ecosystems and processes that underpin human wellbeing is necessary to achieve sustainable development. Here we define critical natural assets as the natural and semi-natural ecosystems that provide 90% of the total current magnitude of 14 types of nature's contributions to people (NCP), and we map the global locations of these critical natural assets at 2 km resolution. Critical natural assets for maintaining local-scale NCP (12 of the 14 NCP) account for 30% of total global land area and 24% of national territorial waters, while 44% of land area is required to also maintain two global-scale NCP (carbon storage and moisture recycling). These areas overlap substantially with cultural diversity (areas containing 96% of global languages) and biodiversity (covering area requirements for 73% of birds and 66% of mammals). At least 87% of the world's population live in the areas benefitting from critical natural assets for local-scale NCP, while only 16% live on the lands containing these assets. Many of the NCP mapped here are left out of international agreements focused on conserving species or mitigating climate change, yet this analysis shows that explicitly prioritizing critical natural assets and the NCP they provide could simultaneously advance development, climate and conservation goals.

Areas of global importance for conserving terrestrial biodiversity, carbon and water.

To meet the ambitious objectives of biodiversity and climate conventions, the international community requires clarity on how these objectives can be operationalized spatially and how multiple targets can be pursued concurrently. To support goal setting and the implementation of international strategies and action plans, spatial guidance is needed to identify which land areas have the potential to generate the greatest synergies between conserving biodiversity and nature's contributions to people. Here we present results from a joint optimization that minimizes the number of threatened species, maximizes carbon retention and water quality regulation, and ranks terrestrial conservation priorities globally. We found that selecting the top-ranked 30% and 50% of terrestrial land area would conserve respectively 60.7% and 85.3% of the estimated total carbon stock and 66% and 89.8% of all clean water, in addition to meeting conservation targets for 57.9% and 79% of all species considered. Our data and prioritization further suggest that adequately conserving all species considered (vertebrates and plants) would require giving conservation attention to ~70% of the terrestrial land surface. If priority was given to biodiversity only, managing 30% of optimally located land area for conservation may be sufficient to meet conservation targets for 81.3% of the terrestrial plant and vertebrate species considered. Our results provide a global assessment of where land could be optimally managed for conservation. We discuss how such a spatial prioritization framework can support the implementation of the biodiversity and climate conventions.

GOODD, a global dataset of more than 38,000 georeferenced dams.

By presenting the most comprehensive GlObal geOreferenced Database of Dams to date containing more than 38,000 dams as well as their associated catchments, we enable new and improved global analyses of the impact of dams on society and environment and the impact of environmental change (for example land use and climate change) on the catchments of dams. This paper presents the development of the global database through systematic digitisation of satellite imagery globally by a small team and highlights the various approaches to bias estimation and to validation of the data. The following datasets are provided (a) raw digitised coordinates for the location of dam walls (that may be useful for example in machine learning approaches to dam identification from imagery), (b) a global vector file of the watershed for each dam.

The environmental consequences of climate-driven agricultural frontiers.

Growing conditions for crops such as coffee and wine grapes are shifting to track climate change. Research on these crop responses has focused principally on impacts to food production impacts, but evidence is emerging that they may have serious environmental consequences as well. Recent research has documented potential environmental impacts of shifting cropping patterns, including impacts on water, wildlife, pollinator interaction, carbon storage and nature conservation, on national to global scales. Multiple crops will be moving in response to shifting climatic suitability, and the cumulative environmental effects of these multi-crop shifts at global scales is not known. Here we model for the first time multiple major global commodity crop suitability changes due to climate change, to estimate the impacts of new crop suitability on water, biodiversity and carbon storage. Areas that become newly suitable for one or more crops are Climate-driven Agricultural Frontiers. These frontiers cover an area equivalent to over 30% of the current agricultural land on the planet and have major potential impacts on biodiversity in tropical mountains, on water resources downstream and on carbon storage in high latitude lands. Frontier soils contain up to 177 Gt of C, which might be subject to release, which is the equivalent of over a century of current United States CO2 emissions. Watersheds serving over 1.8 billion people would be impacted by the cultivation of the climate-driven frontiers. Frontiers intersect 19 global biodiversity hotspots and the habitat of 20% of all global restricted range birds. Sound planning and management of climate-driven agricultural frontiers can therefore help reduce globally significant impacts on people, ecosystems and the climate system.

Can forests buffer negative impacts of land-use and climate changes on water ecosystem services? The case of a Brazilian megalopolis.

While the role of land-use conversion on water quality is reasonably understood, its role on water quantity is controversial. Climate change is also expected to impact water availability. Here we explore the interplay of hydrology, land-use change and climate change in one of the most populous urban areas in the world. We examined the potential of forests to buffer the negative impacts of land-use and climate changes on water-related ecosystem services in Tietê Basin, Brazil, which supplies water to the São Paulo megalopolis. We modelled six hydrological parameters using the WaterWorld Policy Support System, simulating the current baseline and six future scenarios (with different land-use and climate changes). Our results corroborate the general trend that increased forest cover improves water quality. Our modelling also predicts that increased forest cover increases water quantity in the southern part of the basin. The effects of climate change are observed mainly in urban areas, with a reduction in water quality. Because urban areas are not eligible for reforestation, they cannot benefit from its buffering effect on climate change. The increase in water availability is the greatest benefit of reforestation as a strategy to improve water-related ecosystem services in the region. Reforestation, however, will not suffice to restore all hydrological parameters in the basin, and additional sustainable agricultural practices are needed to mitigate impacts on water quality.