Beyond species loss: How anthropogenic disturbances drive functional and phylogenetic homogenization of Neotropical dung beetles

Anthropogenic activities drive tropical forest loss and biodiversity decay. However, few studies have addressed how the biodiversity response varies between disturbance-adapted species (i.e., winners) and those highly susceptible to disturbance (i.e., losers), or whether such responses differ between the taxonomic, functional, or phylogenetic dimensions of diversity. Understanding these dynamics can help prevent or buffer biotic homogenization processes. Using a meta-analytical approach with dung beetles as model organisms, we evaluated how anthropogenic habitat disturbances influence the multiple diversity dimensions of winner and loser species relative to conserved forest sites in the Neotropics. Habitats were organized according to a disturbance gradient ranging from second-growth forests, shaded agroforestry, lowly-shaded agroforestry, living fences, and pastures. Our database included 30 studies, from which we calculated nine metrics divided into three alfa diversity aspects: richness, evenness, and divergence. We also evaluated the beta-diversity response to disturbance and forest protection. All dimensions of dung beetle diversity decreased significantly with increasing disturbance levels, with phylogenetic diversity showing the highest losses, whereas evenness metrics increased in second-growth forests and agroforestry systems. Loser dung beetles showed high diversity loss as well as functional and phylogenetic clustering, reflecting a pervasive biotic homogenization in the most severely disturbed habitats, whereas winner species were insensitive to anthropogenic disturbances. Beta diversity increased significantly with disturbance and forest protection. Our study showed that heavy disturbances erode and homogenized all diversity dimensions of loser dung beetles. However, second-growth forests and agroforestry systems mitigated diversity loss and homogenization processes by favoring the coexistence between functional and phylogenetically distant species and maintaining assemblages compositionally similar to those in conserved forests, highlighting their importance for conservation. We encourage natural resource managers to consider protection of disturbed off-reserve forests in management schemes as these are essential for maintaining biodiversity in an increasingly anthropized world.

Friend or Foe? The Role of Animal-Source Foods in Healthy and Environmentally Sustainable Diets

Scientific and political discussions around the role of animal-source foods (ASFs) in healthy and environmentally sustainable diets are often polarizing. To bring clarity to this important topic, we critically reviewed the evidence on the health and environmental benefits and risks of ASFs, focusing on primary trade-offs and tensions, and summarized the evidence on alternative proteins and protein-rich foods. ASFs are rich in bioavailable nutrients commonly lacking globally and can make important contributions to food and nutrition security. Many populations in Sub-Saharan Africa and South Asia could benefit from increased consumption of ASFs through improved nutrient intakes and reduced undernutrition. Where consumption is high, processed meat should be limited, and red meat and saturated fat should be moderated to lower noncommunicable disease risk-this could also have cobenefits for environmental sustainability. ASF production generally has a large environmental impact; yet, when produced at the appropriate scale and in accordance with local ecosystems and contexts, ASFs can play an important role in circular and diverse agroecosystems that, in certain circumstances, can help restore biodiversity and degraded land and mitigate greenhouse gas emissions from food production. The amount and type of ASF that is healthy and environmentally sustainable will depend on the local context and health priorities and will change over time as populations develop, nutritional concerns evolve, and alternative foods from new technologies become more available and acceptable. Efforts by governments and civil society organizations to increase or decrease ASF consumption should be considered in light of the nutritional and environmental needs and risks in the local context and, importantly, integrally involve the local stakeholders impacted by any changes. Policies, programs, and incentives are needed to ensure best practices in production, curb excess consumption where high, and sustainably increase consumption where low.