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Bees decrease in abundance and richness along elevation gradients, while flies replace bees as the dominant flower visitors in higher elevation systems. We reviewed the existing literature to determine if this global phenomenon of pollinator communities switching from bees to flies occurs at the same place along a temperature gradient. Here we examined five studies that have documented this bee-to-fly transition in the North America, South America, Europe & Australia. We determined where the bee-to-fly transition occurred along a temperature/elevation gradient for each study that ranged from 1.1 to 8.3°C. We found that pollinator communities shifted from bee dominated to fly dominated communities between 4.9 and 5.7°C on all elevation gradients worldwide. This shift in pollinators could substantially impact ecological systems reliant on fly pollination as temperatures continue to warm.

The severe consequences of human disruptions to the global carbon cycle have prompted intense interest in strategies to reduce atmospheric CO2 concentrations. Because growing forests capture CO2 in their biomass and soils, large-scale tree planting efforts have been advertised as a viable way to counteract anthropogenic emissions as part of net-zero emission strategies. Here, we assess the potential impact of reforestation and afforestation on the global climate system, and identify ecological, economic, and societal implications of such efforts.

The United Nations Conference on Environment and Development (UNCED) held in Rio de Janeiro in June 1992 was, without a doubt, a landmark event of contemporary multilateral cooperation. As the largest multilateral gathering ever at the time, the event left a permanent impression on the institutional architecture dealing with environmental issues and shaped the institutions resulting from the Stockholm Conference on the Human Environment. The Rio Conference was thus the starting point of a new institutional era and a new approach to multilateral cooperation for environmental protection. The institutional dimension of the sustainable development question has to address the progress that needs to be accomplished in order to have a better understanding of the sustainable development approach at the national level. It also translates the difficulty in adapting the original mandate of existing institutions to the multifaceted requirements of integration of environmental issues in the economic and social development processes. The institutional dimension requires above all a concerted action towards greater coherence in international action in service of a new multifaceted approach to environmental issues and of a development respectful of the ecological balance of our planet.

More diverse communities are thought to be more stable—the diversity–stability hypothesis—due to increased resistance to and recovery from disturbances. For example, high diversity can make the presence of resilient or fast growing species and key facilitations among species more likely. How natural, geographic biodiversity patterns and changes in biodiversity due to human activities mediate community-level disturbance dynamics is largely unknown, especially in diverse systems. For example, few studies have explored the role of diversity in tropical marine communities, especially at large scales. We tested the diversity–stability hypothesis by asking whether coral richness is related to resistance to and recovery from disturbances including storms, predator outbreaks, and coral bleaching on tropical coral reefs. We synthesized the results of 41 field studies conducted on 82 reefs, documenting changes in coral cover due to disturbance, across a global gradient of coral richness. Our results indicate that coral reefs in more species-rich regions were marginally less resistant to disturbance and did not recover more quickly. Coral community resistance was also highly dependent on pre-disturbance coral cover, probably due in part to the sensitivity of fast-growing and often dominant plating acroporid corals to disturbance. Our results suggest that coral communities in biodiverse regions, such as the western Pacific, may not be more resistant and resilient to natural and anthropogenic disturbances. Further analyses controlling for disturbance intensity and other drivers of coral loss and recovery could improve our understanding of the influence of diversity on community stability in coral reef ecosystems.