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The ability of dry forests to deliver ecosystem services of both local and global relevance depends on the capacity of those forests to recover from constant disturbances in human-modified landscapes. Here we examine the effects posed by biomass, chronic human disturbances and aridity on the recovery of reproductive functional diversity by edible fruit plant assemblages following slash-and-burn agriculture in a Caatinga dry forest, in northeastern Brazil. The edible fruit plant assemblages were described across 24 forest stands, including regenerating stands of varying age (4 to 50 yr old) and old-growth stands, adopting a large set of reproductive traits as floral sizes, reproductive systems, and pollination systems. Such a chronosequence covered a gradient relative to aboveground biomass, aridity, and chronic anthropogenic disturbances (CAD). We observed that edible fruit plant assemblages across both regenerating and old-growth forest stands exhibited similar taxonomic diversity scores. This pattern is also figured in the recovery of reproductive traits, which is relatively fast as regenerating forest scores are generally similar or higher to those in old-growth forests. Generally, regenerating forest stands support more specialized reproductive traits and strategies than old-growth forest stands [e.g., edible fruit plants with very large flowers (>30 mm), specialized pollination systems, large fruits (>1.5 ≤3.0 mm), and medium-sized seeds (>0.6 ≤1.5 cm). However, the functional diversity of specialist reproductive traits decreased with increases in the levels of biomass and aridity, isolated, but was also impacted by the interactive effect. Considering the effects of biomass, CAD or aridity individually, we observed that biomass itself was responsible for most of the effects (42.8%), while 52.3% of the reproductive traits were negatively affected by CAD or aridity, which seems to be a major force against the recovery. [Display omitted] • Secondary forests harbor similar abundance of edible fruit plants as mature forests. • Aridity reduces the species richness of edible fruit plant assemblages. • Secondary forests harbor more specialized traits and strategies than mature forests. • The successional trajectory goes from specialized to generalist traits. • Aridity act as a strong environmental filter against regeneration. [ABSTRACT FROM AUTHOR]

• Longer flowering and fruiting in urban trees of brazilwood in comparison to forest remnant. • Larger flowers with less pollen in urban trees of Paubrasilia echinata. • Impairment in the pollination process of Paubrasilia echinata in urban ecosystem. • Reduced reproductive success of brazilwood in urban compared to natural ecosystem. Human activities have drastically altered natural ecosystems, mostly by converting forests into agricultural and urban areas. Brazilwood (Paubrasilia echinata) is an endangered tree endemic to the Brazilian Atlantic forest originally occurring along the whole coast. The species is largely planted in urban areas due to its ornamental potential. In this paper, we compared the phenology, floral traits and the reproductive success of P. echinata between urban and natural ecosystems. We have hypothesized that individuals in urban ecosystem will have: i) reproductive phenophases lasting longer than in natural, ii) lower number of pollen grains and ovules per flower, iii) lower richness and frequency of flower visitors, and iv) lower natural fruit and seed set. The study was carried out in urban green spaces of the city of Recife and in an Atlantic forest remnant, both in Pernambuco State, northeastern Brazil. The species flowered and fruited practically all year round in the urban ecosystem, contrasting with the annual pattern of flowering and fruiting observed in the natural area. We documented that brazilwood trees in urban areas had smaller inflorescences, fewer flowers/inflorescences, larger flowers, less pollen/flower, lower richness of floral visitors and lower fruit and seed set when compared to natural ecosystem. Also, when considering the most frequent effective pollinator, the invasive bee Apis mellifera predominated in urban, whereas the autochthonous pollinator Centris aenea prevailed in natural. Moreover, C. aenea acted as occasional pollinator in urban area because the flowers of P. echinata are larger in this ecosystem. Independent of the underlying mechanism, the brazilwood had an impoverished richness of native pollinators and a significant reduction in the reproductive success in urban ecosystem, indicating an impairment in the pollination process. The viability of planting trees in tropical urban areas as an ex-situ conservation alternative for species obligatory dependent on cross-pollination, such as P. echinata , may be compromised. [ABSTRACT FROM AUTHOR]

In the last decades several approaches have been adopted for tropical assisted forest restoration from monospecific plantations to the establishment of highly-diverse tree stands. However, the long-term viability of restored forest and their capacity to provide the required services demand continuous evaluation to guide future initiatives. We aimed to evaluate the existence of pollination recovery in monospecific tree plantations in a hyper fragmented landscape of the Atlantic forest in northeast Brazil. By using Inga vera as a model species, we compared several relevant aspects relative to tree reproduction such as reproductive phenology, floral structures, nectar consumption, fruit- and seed-set, between monospecific plantations and native conspecific populations. Populations of I. vera from both native forest stands and planted areas flowered in overlapping periods in the dry season, while fruiting occurred at the beginning of the rainy season. Flowers of planted populations were significantly larger (11% in the size of the calyx, corolla and androecium – staminal tube and filaments) relative to natural populations. Flowers of both planted and natural populations secrete ca. 46 μl of nectar with concentration of 20.2% and 45.8 mg of sugars throughout the anthesis. However, the average volume of nectar consumed by visitors per flower in planted populations was 30% lower than in natural populations. The frequency of pistils with pollen tubes and the average number of seeds per fruit were similar between natural and planted populations. Nevertheless, surprisingly, the natural fruit set was 49% lower in planted relative to natural populations. Lower consumption of nectar and natural fruit set in planted populations of I. vera , in relation to the natural populations, indicate a partial recovery of the pollination process through the practice of planting single species of a tree in clusters of individuals. Our results add some doubts about the long-term viability and the ability of monospecific plantations in delivering services such as increased pollination capacity in human-modified landscapes. [ABSTRACT FROM AUTHOR]

[Display omitted] • Woody plant assemblages along forest regeneration had a higher occurrence of specialized traits and strategies. • Regenerating forest stands also supported a higher (30%) functional diversity of reproductive traits than old-growth stands. • Forest biomass and aridity correlated negatively with reproductive trait diversity. • The Caatinga dry forest regeneration as examined in the community-level plant reproductive context is marked by high resilience. • Aridity and chronic human disturbances did not alter the regeneration trajectory in the Caatinga dry forest. • The Caatinga dry forest regeneration, in the context of slash-and-burn agriculture, is traits-dependent. Tropical forest regeneration across old fields has been mainly described as a predictable sequence of functional plant assemblages in response to environmental filtering. However, the way plant reproductive diversity is organized along forest regeneration and how the reproductive profile of woody flora may impact regeneration have been poorly investigated. This paper examines the organization of plant assemblages throughout the regeneration of a Caatinga dry forest in the context of slash-and-burn agriculture with a focus on reproductive plant traits and strategies. We hypothesized a recovery and directional changes in specialist reproductive traits/strategies along forest regeneration but with aridity and chronic anthropogenic disturbances posing contrary forces to this recovery process. This study was carried out in a human-modified landscape of Caatinga dry forest in northeast Brazil. We compiled information on woody plant assemblages inhabiting a forest chronosequence consisting of 28 forest stands of varying age: 14 regenerating (4–50-yr old) and 14 old-growth forests. Woody plant assemblages along forest regeneration had higher occurrence of specialized traits and strategies, such as pollination by vertebrates (16.6%) and dispersion by animals (47.8%). Regenerating forest stands exhibited a higher occurrence of species with specialized floral size (19%) and pollination by vertebrates (26.5%) as compared to old-growth forests. Regenerating forest stands also supported a higher (30%) functional diversity of reproductive traits than old-growth stands. Biomass, aridity, and chronic anthropogenic disturbances affected a myriad of traits/strategies: pollination by birds and animal dispersion increased with increases in biomass while total functional diversity responded negatively; pollination by Sphingids and beetles negatively responded to aridity, while very large fruit size species negatively responded to chronic anthropogenic disturbances. Both forest biomass and aridity correlated negatively with reproductive trait diversity. The Caatinga dry forest regeneration suggests high resilience, no directional/predictable changes (although regenerating vs. old-growth differ in some traits) and aridity imposed to the successional mosaics as a driver. This pattern probably emerges conditioned by the reproductive traits posed by the plant species able to thrive in such stressful environments, including those species that persist through the entire regeneration process, i.e., the regeneration process is marked by high complexity and low predictive power. Although rapid recovery represents good news, the plant-assemblage reproductive profile imposed by disturbance-adapted species may drastically alter resource availability for a myriad of plant attendants (e.g., pollinators and thief) and, consequently, the complex/diverse plant-animal interactions typical of dry forests. This working hypothesis has both theoretical and applied implications in the context of dry forest regeneration in human-modified landscapes. [ABSTRACT FROM AUTHOR]

• Chronic anthropogenic disturbances and aridity pose negative or positive effects on reproductive traits of edible fruit assemblages in a Caatinga dry forest. • Seventy-five percent of the edible fruit species have specialized reproductive strategies that are negatively affected by chronic disturbances and/or aridity. • Chronic disturbances and aridity negatively affect specialized reproductive traits and strategies of edible fruit assemblages. • Aridity mediates the effects of chronic disturbances mainly on the abundance of specialized reproductive strategies of edible fruit assemblages. • The functional diversity of specialized reproductive strategies of edible fruit assemblages was negatively affected by aridity. Chronic anthropogenic disturbances and climate change are the main threats to biodiversity, acting as potential drivers of assembly reorganization in human-modified tropical landscapes. We aimed to understand how the reproductive traits of edible fruit plant assemblages respond to chronic disturbances and aridity in the Caatinga, a dry forest in northeastern Brazil housing a human population that greatly depends on natural resources for subsistence and is threatened by increasing aridity. The study was carried out across 20 permanent plots of Caatinga, covering gradients of chronic disturbances (livestock grazing, wood extraction and non-timber product exploitation) and aridity (1051 mm to 664 mm). We registered 24 native plant species with fruits that are edible for humans, which were classified according to their flowering/fruiting pattern, floral size and reward, sexual and reproductive systems, pollination systems, and fruit types. They were also grouped into two categories of reproductive strategies (generalists and specialists). We documented that chronic disturbances and aridity pose more negative than positive effects on the reproductive traits of edible fruit plants in terms of trait richness (negative: 29% of the traits; positive: 3.2%) and abundance (negative: 19.3%; positive: 3.2%). In general, we observed that 79.2% of the studied species had at least one reproductive trait that was negatively reduced by increased chronic disturbance and/or aridity in terms of trait richness and abundance. Overall, 75% of the edible fruit species have specialized reproductive strategies that were negatively affected by chronic disturbances and/or aridity. Specifically, individual or combined effects of chronic anthropogenic disturbances or aridity negatively impacted the richness and abundance of specialized reproductive traits such as supra-annual flowering and fruiting patterns and obligatory cross-pollinated edible fruit species. Also, in terms of richness, the reproductive functional diversity of specialized reproductive strategies was negatively affected by increasing aridity. Our findings indicate that in the expected future scenarios of increased land-use and climate change, the Caatinga could face a collapse in the offer of edible fruits to local human communities by impacting the provision of this ecosystem service. [ABSTRACT FROM AUTHOR]

Animal pollination services provide multiple benefits to humanity as they contribute to 35% of global food production and directly account for up to 40% of the dietary nutrient supply to humanity worldwide. Population declines of vertebrate and invertebrate pollination vectors may threaten human nutrition and well-being, particularly where agriculture relies heavily on animal pollinators. We examined the relative differences in nutrient concentrations of 45 leading crops produced throughout Brazil, the world's largest tropical agricultural producer and exporter. We also estimated the overall reductions in nutrient yields under different scenarios of pollinator declines, based on annual agricultural production. Of the 45 top-ranking crops, 29 and 16 were classified as pollinator-dependent and non-dependent, respectively. Pollinator-dependent crops provided 47% of all dietary nutrients supplied in 2017, which had significantly higher concentrations of lipids, vitamin B9, and potassium, while pollinator non-dependent crops provided higher carbohydrate content. Under either a best- or worst-case pollinator declines scenario, we estimate overall nutritional losses of 7.9% and 29.5%, respectively. These losses ranged from 4% to 18% for all macronutrients, 6.8%–26.2% for all minerals, and 2.4%–31.5% for all vitamins. We emphasize the need for land-use strategies that sustain, if not increase pollinator abundance and species diversity to ensure agricultural viability and future food security. [Display omitted] • Nutrient production is heavily associated with pollinator-dependent crops. • Pollinator-dependent crops in Brazil outnumber non-dependent crops. • Concentrations of lipids, vitamin B9 and potassium are higher in pollinator-dependent crops. • Pollinator-dependent crops provide 47% of all nutrients for humans and livestock feed. • Nutritional losses between 7.9% and 29.5% are expected under a pollinator declines scenario. [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.

• Exotic trees predominate in tropical urban spaces. • 100 % of self-incompatible exotic trees set fruit in tropical urban ecosystem. • Exotic trees pose risk to native species and threaten urban and natural ecosystems. • Native plants should be the first choice in tropical urban ecosystems. Urban ecosystems provide green landscapes that are important to global biodiversity conservation. In tropical urban ecosystems, exotic plants are widely used in landscaping and this can have several negative effects on the native plant and pollinator communities. Here, we aimed to investigate the origin (native or exotic to Brazil, and native or exotic to the phytogeographic dominium where the urban space is inserted), sexual and reproductive systems and fruiting of tree species occurring in 17 urban green spaces in the city of Recife, Pernambuco, located in the northeastern Brazilian Atlantic forest. A total of 114 tree species were registered in the urban green spaces, 78 out of them were observed for fruiting. Overall, 49.1 % of the species are native to Brazil and 50.9 % are exotic, while 86 % do not occur naturally in the northeastern Brazilian Atlantic forest. In terms of abundance of individuals, these values were 37 % native, 63 % exotic and 80.5 % not occurring in the northeastern Brazilian Atlantic forest. Most of the species, native or exotic, are hermaphrodite and self-incompatible (i.e. obligatory cross-pollinated). From the 78 species observed for fruiting, 77 set fruits, 43.7 % had sub-annual pattern; all exotic species (43 spp.) set fruits, even the 13 exotic species that are self-incompatible. Our results reveal that factors such as the high use of exotic species that successfully set fruits in tropical urban green spaces may indicate risks for plant-animal interactions (e.g. pollination; dispersion), threaten the reproductive success of native plant species, increase the risk of biological invasion, and consequently impair the maintenance of biodiversity. We suggest that decision makers pay attention and consider the impacts of using exotic plant species in the dynamic of tropical urban ecosystems. [ABSTRACT FROM AUTHOR]