Ecological intensification, or the improvement of crop yield through enhancement of biodiversity, may be a sustainable pathway toward greater food supplies. Such sustainable increases may be especially important for the 2 billion people reliant on small farms, many of which are undernourished, yet we know little about the efficacy of this approach. Using a coordinated protocol across regions and crops, we quantify to what degree enhancing pollinator density and richness can improve yields on 344 fields from 33 pollinator-dependent crop systems in small and large farms from Africa, Asia, and Latin America. For fields less than 2 hectares, we found that yield gaps could be closed by a median of 24% through higher flower-visitor density. For larger fields, such benefits only occurred at high flower-visitor richness. Worldwide, our study demonstrates that ecological intensification can create synchronous biodiversity and yield outcomes.

Surveys of local assemblages of plants and their pollinators are among the most useful ways to evaluate specialization in pollination and to discuss the patterns of plant-pollinator interactions among ecosystems. The high-altitude grasslands from southeastern Brazil constitute diminutive island-like formations surrounded by montane rainforests. We registered the floral traits of 124 species from the Serra da Bocaina grasslands (about 60% of the animal-pollinated species of this flora), and determined the pollinators of 106 of them. Asteraceae (40 species) and Melastomataceae (10 species) were prominent, while most families were represented by few species. The predominant floral traits were: dish or short-tubular shape; nectar as a reward; and greenish or violaceous colors. Pollinators were divided into eight functional groups (small bees, syrphids, other dipterans, etc.) and small bees, wasps, and large bees were the most important pollinators. Butterflies, beetles, and hummingbirds were poorly represented, and no bats, hawkmoths, or odor-collecting bees were detected. Plants were grouped in nine pollination systems, among which nectar-flowers pollinated by bees (28%), by wasps or wasps and flies (21%), or by several insect groups (19%) were the most representative. With regard to the degree of specialization, plant species were classified according to their number of pollinator groups. About 33% of the species were monophilous and 30% were oligophilous (i.e., pollinated by one or two functional groups, respectively). The remaining species were either polyphilous (17%) or holophilous (19%), a highly generalist system in which at least three groups act as indistinct pollinators. The general trends of the floral traits and plant-pollinator interactions at the Bocaina grasslands resemble those of biogeographicconnected ecosystems, such as the Venezuelan arbustal, and the Brazilian campo rupestre and cerrado. However, in the Bocaina grasslands, the mean number of pollinator types per plant was 2.09, one of the highest values obtained for worldwide floras. The origin of the high-altitude grasslands is linked to episodes of expansion and retraction due to glacial events. Such a situation may have favored species able to quickly occupy new habitats, including those that do not depend on a few highly specialized pollinators. The prevalence of Asteraceae may also be linked to more generalized pollination systems. Alternatively, some floral traits, such as spontaneous self-pollination and long-lived flowers, may be advantageous for species with more specialized systems in these grasslands with harsh climatic conditions and low rates of pollinator visitation.

Colour is one of the most obvious advertisements of flowers, and occurs in a huge diversity among the angiosperms. Flower colour is responsible for attraction from a distance, whereas contrasting colour patterns within flowers aid orientation of flower visitors after approaching the flowers. Due to the striking differences in colour vision systems and neural processing across animal taxa, flower colours evoke specific behavioural responses by different flower visitors. We tested whether and how yellow flowers differ in their spectral reflectance depending on the main pollinator. We focused on bees and birds and examined whether the presence or absence of the widespread UV reflectance pattern of yellow flowers predicts the main pollinator. Most bee-pollinated flowers displayed a pattern with UV-absorbing centres and UV-reflecting peripheries, whereas the majority of bird-pollinated flowers are entirely UV- absorbing. In choice experiments we found that bees did not show consistent preferences for any colour or pattern types. However, all tested bee species made their first antennal contact preferably at the UV-absorbing area of the artificial flower, irrespective of its spatial position within the flower. The appearance of UV patterns within flowers is the main difference in spectral reflectance between yellow bee- and bird-pollinated flowers, and affects the foraging behaviour of flower visitors. The results support the hypothesis that flower colours and the visual capabilities of their efficient pollinators are adapted to each other.

The concept of pollination syndromes has been widely questioned, since plant–pollinator interactions have proved to be more generalist than was previously thought. We examined whether the network of a tropical high‐altitude grassland contained groups of plants and pollinators that interact preferentially with each other. A general binary matrix was created. To assess the robustness of myophily, in all analyses we considered: 1) the whole network, 2) the network after the wasps were removed, and 3) the network after the flies were removed. For each network we evaluated whether: 1) the observed interactions were more related to syndromes than expected by chance, compared to an expected matrix; 2) there was a modular structure; 3) the modules found were more related to syndromes than expected by chance, compared to another expected matrix; 4) the syndromes were equally robust. For this analysis, the general matrix was subdivided into smaller matrices that included each pollination syndrome separately. To test the influence of the functional groups of pollinators and the phylogeny of plants, in addition to the general matrix, we also considered the first expected matrix, a quantitative functional group and a plant phylogeny matrix. The pollination syndromes determined the pattern of interactions in the network: 69% of the total interactions resulted from the functional group of pollinators predicted by the plant syndrome. The network showed greater modularity (13 modules) than expected by chance, mostly consisting of the expected functional groups of pollinators and plant syndromes. The modules were associated with pollination syndromes more than was predicted by chance. Most of the variation in interactions was explained by functional groups of pollinators or by plant syndromes. Plant phylogeny did not account for a significant amount of variation in the interactions. Our findings support the concept of pollination syndromes. However, the interactions were not equally predicted by different pollination syndromes, and the accuracy of the prediction was strongest for ornithophily and melittophily.

Land use change, by disrupting the co-evolved interactions between plants and their pollinators, could be causing plant reproduction to be limited by pollen supply. Using a phylogenetically controlled meta-analysis on over 2200 experimental studies and more than 1200 wild plants, we ask if land use intensification is causing plant reproduction to be pollen limited at global scales. Here we report that plants reliant on pollinators in urban settings are more pollen limited than similarly pollinator-reliant plants in other landscapes. Plants functionally specialized on bee pollinators are more pollen limited in natural than managed vegetation, but the reverse is true for plants pollinated exclusively by a non-bee functional group or those pollinated by multiple functional groups. Plants ecologically specialized on a single pollinator taxon were extremely pollen limited across land use types. These results suggest that while urbanization intensifies pollen limitation, ecologically and functionally specialized plants are at risk of pollen limitation across land use categories.

Despite evidence of pollinator declines from many regions across the globe, the threat this poses to plant populations is not clear because plants can often produce seeds without animal pollinators. Here, we quantify pollinator contribution to seed production by comparing fertility in the presence versus the absence of pollinators for a global dataset of 1174 plant species. We estimate that, without pollinators, a third of flowering plant species would produce no seeds and half would suffer an 80% or more reduction in fertility. Pollinator contribution to plant reproduction is higher in plants with tree growth form, multiple reproductive episodes, more specialized pollination systems, and tropical distributions, making these groups especially vulnerable to reduced service from pollinators. These results suggest that, without mitigating efforts, pollinator declines have the potential to reduce reproduction for most plant species, increasing the risk of population declines.

Within Apocynaceae, interactions with pollinators are highly structured both phylogenetically and biogeographically. Variation in transition rates between pollination systems suggest constraints on their evolution, whereas regional differences point to environmental effects such as filtering of certain pollinators from habitats. This is the most extensive analysis of its type so far attempted and gives important insights into the diversity and evolution of pollination systems in large clades.

Knowledge of the geographic distribution of plants is essential to underpin the understanding of global biodiversity patterns. Vascular epiphytes are important components of diversity and functionality of Neotropical forests but, unlike their terrestrial counterparts, they are under-represented in large-scale diversity and biogeographic analyses. This is the case for the Atlantic Forest - one of the most diverse and threatened biomes worldwide. We provide the first comprehensive species list of Atlantic Forest vascular epiphytes; their endemism patterns and threatened species occurrence have also been analyzed. A list with 2,256 species of (hemi-)epiphytes - distributed in 240 genera and 33 families - is presented based on the updated Brazilian Flora Checklist. This represents more than 15% of the total vascular plant richness in the Atlantic Forest. Moreover, 256 species are included on the Brazilian Red List. More than 93% of the overall richness is concentrated in ten families, with 73% represented by Orchidaceae and Bromeliaceae species alone. A total of 78% of epiphytic species are endemic to the Atlantic Forest, in contrast to overall vascular plant endemism in this biome estimated at 57%. Among the non-endemics, 13% of epiphytic species also occur either in the Amazon or in the Cerrado - the other two largest biomes of Brazil – and only 8% are found in two or more Brazilian biomes. This pattern of endemism, in addition to available dated phylogenies of some genera, indicate the dominance of recent radiations of epiphytic groups in the Atlantic Forest, showing that the majority of divergences dating from the Pliocene onwards are similar to those that were recently reported for other Neotropical plants.