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Pollinator diversity plays an important role in improving the resilience of pollination services. However, agricultural intensification is causing declines in pollinator diversity. Such losses could be mitigated and even reversed by agroforestry systems, whose structural complexity exceeds that of intensive agricultural systems. Research, primarily conducted in tropical regions, suggests that efficiently managing agroforestry systems can increase pollinator diversity. We performed a global meta‐analysis to explore how coffee agroforestry management practices affect the diversity of bee pollinators. We employed 137 sets of results from 20 studies that had been conducted at widely distributed locations across four of the seven continents. More specifically, we investigated the impact of augmenting floral resources (60 sets of results) and shade‐tree cover (43 sets of results) and reducing the distance to natural forests (34 sets of results). Additionally, we examined key moderating factors, including climatic conditions, pollinator sociality, the metrics used to describe pollinator diversity, pollinator sampling methods, the metrics used to characterise the effects of management practices and floral resource type. We observed that bee pollinator diversity broadly increased as local floral resources increased in tropical coffee agroforestry systems. Shade‐tree cover and proximity to natural forests did not broadly influence bee pollinator diversity. However, the strength and direction of the relationships between the agroforestry management practices and bee pollinator diversity were moderated by different factors, mainly climatic conditions and pollinator sociality. Our findings underscore the importance of managing coffee agroforestry systems to maximise bee diversity, which is crucial for coffee plant pollination. The broader objective should be to ensure the availability of resources that promote pollinator fitness, effective pollination and, as a consequence, crop yields. [ABSTRACT FROM AUTHOR]

Plant reproduction is influenced by resource availability, environment and interactions with pollinators, pathogens and herbivores. In the Neotropical region, the leaf‐cutting ants are voracious herbivores and soil engineers, potentially affecting plant performance. This study investigated the effects of herbivory and soil changes via nest construction and maintenance linked to Atta opaciceps (Hymenoptera: Formicidae) (Bormeier, 1939) on the reproductive success of two Leguminosae species (Cenostigma pyramidale (Tul.) E. Gagnon & G.P. Lewis and Indigofera suffruticosa Mill. Mill.) widely distributed in the Caatinga dry forest.We selected eight nests from A. opaciceps colonies, with both plant species nearby. For each colony, we selected similar‐sized adult plants from foraging trail ends, where ants concentrate foraging efforts and herbivory is pronounced. We also selected plants located 20 m away from the foraging trail ends, representing herbivory‐protected scenarios, secured by tanglefoot barriers. Additionally, to assess ant‐related soil effects, we selected individuals from different nest‐associated soils (i.e., nest mounds and external refuse dumps) and from locations 20 m away from the aforementioned locations. All these individuals were shielded with tanglefoot barriers.Herbivory and soil changes from A. opaciceps did not affect any metric evaluated of C. pyramidale. Yet, for I. suffruticosa, ant herbivory boosted fruit set, and nest‐related soil changes, notably from refuse dumps, increased the number of flowers and fruits.Our findings indicate that leaf‐cutting ant effects on plant performance are species‐specific and may eventually benefit plant reproduction. Given the proliferation of leaf‐cutting ants in human‐modified landscapes of the Caatinga dry forest, positive interactions with plants might be vital to improving plant recruitment and forest regeneration dynamics. [ABSTRACT FROM AUTHOR]

Chronic anthropogenic disturbances and climate change have been recognized as drivers of biological reorganization across human‐modified tropical landscapes, also negatively affecting the reproductive output of some plant species. Here, we investigated to what extent these drivers affect the reproductive output of Cenostigma microphyllum, a disturbance‐adapted tree species endemic to the Caatinga dry forest. The production of flowers/inflorescence, fruits and seeds was estimated for 105 plants (≥3 cm diameter at soil height) across 11 forest stands (20 × 50 m each), covering gradients of chronic disturbances (e.g. goat and livestock herbivory; wood extraction; and removal of non‐timber forest products) and aridity at the Catimbau National Park. We documented that when the drivers were analysed in isolation, the fruit‐set was positively associated with increased wood extraction, and the fruit‐set and total number of seeds/plots were reduced under increasing aridity. We also verified a complex interaction between wood extraction and aridity emerged. In forest stands, the combination of high levels of aridity and wood extraction leads to a decrease in the fruit‐set and total number of seeds/plots. Conversely, the fruit‐set and total number of seeds/plots increased in stands exposed to lower aridity but high levels of wood extraction. Our results suggest that chronic disturbances and aridity affect plant fitness in a complex way including both negative and positive effects on attributes related to plant reproductive performance, which could result in both proliferation and population decline in the same landscape. Although C. microphyllum benefits from anthropogenic disturbances and is considered a disturbance‐adapted species, it apparently does not benefit from increases in aridity, which is an expected future scenario for the Caatinga dry forest. [ABSTRACT FROM AUTHOR]

It's raining fragrant nectar in the Caatinga: evidence of nectar olfactory signaling in bat-pollinated flowers The physiology of bat-pollinated flowers is particularly striking because the flowers secrete large amounts of nectar and emit peculiar odors (Fleming et al. [2]). To measure nectar production, we first quantified the total volume produced and the concentration of nectar in individual flowers ( I n i = 100 flowers; 10 flowers per individual). To characterize the nectar scent, we collected separate samples of volatile compounds emitted only by flowers without nectar ( I n i = 10 samples, each one collected from three to five flowers, from which we have completely removed the nectar) and only by nectar ( I n i = 10 samples, each one with the nectar we had been removed from the previously mentioned flowers). [Extracted from the article]

Abstract: Aim: We examined the effects of space, climate, phylogeny and species traits on module composition in a cross‐biomes plant–hummingbird network. Location: Brazil, except Amazonian region. Methods: We compiled 31 local binary plant–hummingbird networks, combining them into one cross‐biomes metanetwork. We conducted a modularity analysis and tested the relationship between species’ module membership with traits, geographical location, climatic conditions and range sizes, employing random forest models. We fitted reduced models containing groups of related variables (climatic, spatial, phylogenetic, traits) and combinations of groups to partition the variance explained by these sets into unique and shared components. Results: The Brazilian cross‐biomes network was composed of 479 plant and 42 hummingbird species, and showed significant modularity. The resulting six modules conformed well to vegetation domains. Only plant traits, not hummingbird traits, differed between modules, notably plants’ growth form, corolla length, flower shape and colour. Some modules included plant species with very restricted distributions, whereas others encompassed more widespread ones. Widespread hummingbirds were the most connected, both within and between modules, whereas widespread plants were the most connected between modules. Among traits, only nectar concentration had a weak effect on among‐module connectivity. Main conclusions: Climate and spatial filters were the main determinants of module composition for hummingbirds and plants, potentially related to resource seasonality, especially for hummingbirds. Historical dispersal‐linked contingency, or environmental variations not accounted for by the explanatory factors here evaluated, could also contribute to the spatial component. Phylogeny and morphological traits had no unique effects on the assignment of species to modules. Widespread species showed higher within‐ and/or among‐module connectivity, indicating their key role connecting biomes, and, in the case of hummingbirds, communities within biomes. Our results indicate that biogeography and climate not only determine the variation of modularity in local plant–animal networks, as previously shown, but also affect the cross‐biomes network structure. [ABSTRACT FROM AUTHOR]

Mimosa lewisii (Section Batocaulon), a shrub of the NE-Brazilian Caatinga, presents huge (pseudo-)racemes that form a separate storey overtopping the foliage. Racemes persist, developing intermittently pedunculate capitula over a period of more than one year. The brush-type, whitish flower heads are nocturnal in anthesis and active only a single night. Florets are relatively large and stout for the genus, hermaphroditic, with stiff filaments and style, and converge towards the periphery of the raceme. When expanding at dusk, the heads produce large nectar drops (up to 173 µl per head), that averages 25-29% sucrose. Production starts sequentially among florets of a capitulum. The drops are freely exposed, held between the filaments. The glossophagine bat Lonchophylla mordax was observed as the only legitimate visitor; hummingbirds exploited worn capitula at daytime, but did not pollinate. The bats lapped the nectar while hovering without apparently putting out their tongues. Pollen transmission was by the snout and probably by touching neighbouring flower heads with the wings. The blossoms, of a genus predominantly entomophilous, reveal habitual adaptation to bat pollination in most of their features. Small size (14 mm in diam.) and lack of a perceptible scent suggest that an evolutionary shift towards chiropterophily is still incomplete. A brief survey of the known distribution of bat pollination in Mimosaceae is appended. [ABSTRACT FROM AUTHOR]

Reports on the adaptation of Acanthaceae (Harpochilus neesianus) to the pollination by glossophaga soricina in Brazil. Release of sour, cabbage-like odor and secretion of nectar during pollination of bats to Acanthacaea; Examination on the occurrence of pollination of the flower in other genera of its family; Reduction of chiropterophily in Ruellia eurycodon.