Biodiversité

Area-based conservation, including protected areas and OECMs, is the primary approach used to address biodiversity decline and now covers 8% of the world’s oceans and 17% of its lands. As it is set to diversify and expand under the 30x30 target to protect30% of the planet by 2030, we take stock of the approach, including its history in global policy and performance. We outline three priority directions to ensure area-based
conservation contributes to securing a sustainable and just future.

A ‘Blueprint’ to save critical ecosystems and stabilize the Earth’s climate.

More than two years in development, the Global Safety Net is the first comprehensive global-scale analysis of terrestrial areas essential for biodiversity and climate resilience, totaling 50.4% of the Earth's land. The report was published in Science Advances and highlights the importance of protecting and restoring the natural world to address three converging crises -- climate change, the loss of biodiversity, and the emergence of novel viruses such as COVID-19.

It is no secret that habitat destruction and fragmentation are the leading causes of biodiversity loss worldwide, and climate change is only making it worse. Species blinking out, shrinking populations and significant range contractions caused by human activities have negative impacts on biodiversity as well as ecosystem functions and services. Extinction events have happened before […]

Fragmentation of ecosystems leads to loss of biodiversity in the remaining habitat patches, but retaining connecting corridors can reduce these losses. Using long-term data from a large, replicated experiment, Damschen et al. show quantitatively how these losses are reduced. In their pine savanna system, corridors reduced the likelihood of plant extinction in patches by about 2% per year and increased the likelihood of patch colonization by about 5% per year. These benefits continued to accrue over the course of the 18-year experiment.

Expansive development for urbanization, agriculture, and resource extraction has resulted in much of the Earth’s vegetation existing as fragmented, isolated patches. Conservation planning typically deprioritizes small, isolated patches, as they are assumed to be of relatively little ecological value, instead focusing attention on conserving large, highly connected areas. Yet, our global analysis shows that, if we gave up on small patches of vegetation, we would stand to lose many species that are confined to those environments, and biodiversity would decline as a result. We should rethink the way we prioritize conservation to recognize the critical role that small, isolated patches play in conserving the world’s biodiversity. Restoring and reconnecting small isolated vegetation patches should be an immediate conservation priority.

Abstract

Le « filet de sécurité mondial » décrit comment une conservation étendue de la nature répond à ces deux menaces globales. Les auteurs identifient 50% du domaine terrestre qui, s’il était conservé, inverserait la tendance future à la perte de biodiversité, empêcherait les émissions de CO2 dues au changement d’usage des terres et renforcerait le […]

Habitat connectivity is essential for maintaining populations of wildlife species, especially as climate changes. Knowledge about the fate of existing habitat networks in a changing climate and in light of land-use change is critical for determining which types of conservation actions must be taken to maintain those networks. However, information is lacking about how multiple focal species that use similar habitats overlap in the degree and geographic patterns of threats to linkages among currently suitable habitat patches. We sought to address that gap. We assessed climate change threat to existing linkages in the southeastern United States for three wildlife species that use similar habitats but differ in the degree to which their ranges are limited by climate, habitat specificity, and dispersal ability.

Face à l’inefficacité des zonages classiques de protection pour enrayer la perte de biodiversité, la mise en connexion des habitats naturels pour permettre aux espèces animales et végétales de se déplacer est devenue un enjeu majeur des politiques environnementales. L’identification et la gestion des réseaux écologiques soulève néanmoins des difficultés face à la diversité des méthodes pour analyser la connectivité et le manque de données harmonisées à l’échelle d’un pays. L’objectif de cette étude est d’utiliser la théorie des graphes pour intégrer plus finement la connectivité fonctionnelle du paysage dans la modélisation des réseaux écologiques à différentes échelles spatiales.