Global climate change alters the dynamic of natural ecosystems and directly affects species distributions, persistence and diversity. The impacts of climate change may lead to dramatic changes in biotic interactions, such as pollination and seed dispersal. Life history traits are extremely important to consider the vulnerability of a species to climate change, producing more robust models than those based primarily on species distributions. Here, we hypothesized that rising temperatures and aridity will reduce suitable habitats for the endemic flora of the Caatinga, the most diverse dry tropical forest on Earth. Specifically, species with specialized reproductive traits (e.g. vertebrate pollination, biotic dispersal, obligatory cross-pollination) should be more affected by climate change than those with generalist traits. We performed two ecological niche models (current and future) to simulate the effects of climate change on the distribution area of endemic species in relation to life-history traits. We used the MIROC-ESM and CCSM4 models for both intermediate (RCP4.5) and highest predicted (RCP8.5) GHG emission scenarios, with a resolution of 30' (~1 km 2 ). Habitat with high occurrence probability (>80%) of endemic species will be reduced (up to ~10% for trees, ~13% for non-arboreous, 10–28% for species with any pollination/reproductive system), with the greatest reductions for species with specialized reproductive traits. In addition, the likely concentration of endemic plants in the extreme northeastern portion of the Caatinga, in more mesic areas, coincides with the currently most human-modified areas of the ecosystem, which combined with climate change will further contract suitable habitats of endemic species. In conclusion, plant species endemic to the Caatinga are highly vulnerable to even conservative scenarios of future climate change and may lose much of their climatic envelopes. New protected areas should be located in the northeastern portion of the Caatinga, which hosts a more favorable climate, but is currently exposed to escalating agricultural intensification.

Urbanization has rapidly increased in recent decades and the negative effects on biodiversity have been widely reported. Urban green areas can contribute to improving human well-being, maintaining biodiversity, and ecosystem services (e.g. pollination). Here we examine the evolution of studies on plant-pollinator interactions in urban ecosystems worldwide, reviewing also research funding and policy actions. We documented a significant increase in the scientific production on the theme in recent years, especially in the temperate region; tropical urban ecosystems are still neglected. Plant-pollinator interactions are threatened by urbanization in complex ways, depending on the studied group (plant or pollinator [generalist or specialist]) and landscape characteristics. Several research opportunities emerge from our review. Research funding and policy actions to pollination/pollinator in urban ecosystems are still scarce and concentrated in developed countries/temperate regions. To make urban green spaces contribute to the maintenance of biodiversity and the provision of ecosystem services, transdisciplinary approaches (ecological-social-economic-cultural) are needed.

This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

No abstract

No abstract

No abstract

Pollinators provide essential ecosystem services worldwide, but dependence on biotic pollination is higher in the tropics, where urbanization is expected to impact biodiversity more severely. Here, we present a global review on urban pollinator studies with emphasis on the tropics. From the 308 published studies that included information on pollinator groups, only ~25 % were conducted in tropical regions, while ~65 % were carried out in the non-tropical northern hemisphere. This overall trend was similar for all the major insect pollinator groups, but not for vertebrates, which were overall less studied in both tropical and non-tropical regions. The effects of urbanization on tropical pollinators are diverse and complex and likely depend on the extent and type of urbanization, as well as the pollinator taxa studied. For both insect and vertebrate pollinators, the existing studies suggest that tropical cities can support generalist species tolerant of human activity, but the lack of studies hampers other general conclusions. The underrepresentation of pollinator studies in tropical cities undermines the value of urban biodiversity conservation in the most biodiverse regions of the world and highlights a missing opportunity. Since promoting urban biodiversity benefits both nature and people, it could be especially relevant in the Global South, where economic and social inequalities are severe and pollinator conservation may contribute to sustainability goals. In this context, initiatives that foster more international collaborations and research in the tropics are essential for a better understanding of the effects of urbanization and the value of pollinators in urban areas. Such knowledge can provide the basis for better urban planning strategies that contribute to the conservation of biodiversity and maintenance of pollination services in tropical cities.

No abstract