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For a better production, agriculture areas need to recover at least 20% of natural habitat

International agreements aim to conserve 17% of Earth's land area by 2020 but include no area-based conservation targets within the working landscapes that support human needs through farming, ranching, and forestry. Through a review of country-level legislation, this study found that just 38% of countries have minimum area requirements for conserving native habitats within working landscapes. The study argues for increasing native habitats to at least 20% of working landscape area where it is below this minimum. Such target has benefits for food security, nature's contributions to people, and the connectivity and effectiveness of protected area networks in biomes in which protected areas are underrepresented. Other urgings of the review include maintaining native habitat at higher levels where it currently exceeds the 20% minimum, and a literature review shows that even more than 50% native habitat restoration is needed in particular landscapes. Including a >20% native habitats within working landscapes restoration target offers an unrivaled opportunity to simultaneously enhance biodiversity, food security and quality of life. The post-2020 Global Biodiversity Framework is an opportune moment to include a minimum habitat restoration target for working landscapes that contributes to, but does not compete with, initiatives for expanding protected areas, the UN Decade on Ecosystem Restoration (2021–2030) and the UN Sustainable Development Goals. informacion[at] Garibaldi et al (2020) Working landscapes need at least 20% native habitat. Conserv Letter DOI: 10.1111/conl.12773
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Disentangling the abundance–impact relationship for invasive species

Disentangling the abundance–impact relationship for invasive species

To predict the threat of biological invasions to native species, it is critical to understand how increasing abundance of invasive alien species (IAS) affects native populations and communities. The form of this relationship across taxa and ecosystems is unknown, but is expected to depend strongly on the trophic position of the IAS relative to the native species. Using a global metaanalysis based on 1,258 empirical studies presented in 201 scientific publications, the authors assessed the shape, direction, and strength of native responses to increasing invader abundance. They also tested how native responses varied with relative trophic position and for responses at the population vs. community levels. As IAS abundance increased, native populations declined nonlinearly by 20%, on average, and community metrics declined linearly by 25%. When at higher trophic levels, invaders tended to cause a strong, nonlinear decline in native populations and communities, with the greatest impacts occurring at low invader abundance. In contrast, invaders at the same trophic level tended to cause a linear decline in native populations and communities, while invaders at lower trophic levels had no consistent impacts. At the community level, increasing invader abundance had significantly larger effects on species evenness and diversity than on species richness. These results show that native responses to invasion depend critically on invasive species' abundance and trophic position. Further, these general abundance–impact relationships reveal how IAS impacts are likely to develop during the invasion process and when to best manage them. información[at] Bradley et al (2019) Disentangling the abundance–impact relationship for invasive species. Proc Natl Acad Sci USA