The foraging range of bees determines the spatial scale over which each species can provide pollination services. In agricultural ecosystems, productivity is related not only to the taxonomic diversity of bees per se, but also to the location of their nesting sites, which reflects on their flying range. Within this context, the present study sought to assess how wild bee assemblages affect the yield of Brassica napus at three different distances (25 m, 175 m, 325 m) from forest remnants in Southern Brazil. Bees were sampled by means of pan traps and findings were analyzed using the Shannon diversity index and generalized linear models. We identified 11 species of native bees, both solitary and social, as well as the exotic species Apis mellifera, which was most abundant. Our findings show that canola crop yield were positively influenced by the diversity of bee species. This demonstrates that native bees, not only A. mellifera, can contribute significantly to the productivity of canola crops. In addition, we found that bee body size is significantly associated with flight distance traveled within the canola fields, and demonstrated a relationship with nesting sites. Thus, we hypothesize that canola yields are associated with the presence of wild bee species, both social and solitary, and that maintenance of these pollinators is directly dependent on practices adopted in rural areas, whether within plantation fields per se or in forest remnants used as nesting sites by wild bees.

Invasive species can reach high abundances and dominate native environments. One of the most impressive examples of ecological invasions is the spread of the African sub-species of the honey bee throughout the Americas, starting from its introduction in a single locality in Brazil. The invasive honey bee is expected to more negatively impact bee community abundance and diversity than native dominant species, but this has not been tested previously. We developed a comprehensive and systematic bee sampling scheme, using a protocol deploying 11,520 pan traps across regions and crops for three years in Brazil. We found that invasive honey bees are now the single most dominant bee species. Such dominance has not only negative consequences for abundance and species richness of native bees but also for overall bee abundance (i.e., strong "numerical" effects of honey bees). Contrary to expectations, honey bees did not have stronger negative impacts than other native bees achieving similar levels of dominance (i.e., lack of negative "identity" effects of honey bees). These effects were remarkably consistent across crop species, seasons and years, and were independent from land-use effects. Dominance could be a proxy of bee community degradation and more generally of the severity of ecological invasions.

Ecosystem services are fundamental to the maintenance of biodiversity, food security, livestock and biofuel production. Here, we analyze the impact of the distance between forest fragments and oilseed crops (Brassica napus) on the crops' yield (kg/ha) and economic value (US$). For crop yield, the total loss field −1 was calculated as the difference between the most lucrative parcel and the least lucrative parcel. Hypothetical models were developed to estimate the potential changes in crop incomes due to progressive replacement of the lowest income crop area(s) by natural vegetation. Our findings demonstrate a significant decrease in the mean number of seeds per silique and in seed production as the distance from forest fragment progressively increases. The productivity loss throughout this gradient may reach up to 2760 kg/ha (i.e. US$804.08). Our models indicate that parcels further than 325 m from forest fragments were poorly pollinated. Our models also demonstrated that farmers could boost their yields if more natural areas (as small as 5%) were included inside crop fields, even though this reduces their arable area. In conclusion, adding small natural patches within crop fields will most likely lead to a higher seed production and successive increases in the economic value of canola crops.

Seventy five percent of fruit production of the major global crops benefit from insect pollination. Hence, there has been increased interest in how global change drivers impact this critical ecosystem service. Because standardized data on crop pollination are rarely available, we are limited in our capacity to understand the variation in pollination benefits to crop yield, as well as to anticipate changes in this service, develop predictions, and inform management actions. Here, we present CropPol, a dynamic, open and global database on crop pollination. It contains measurements recorded from 189 crop studies, covering 3,216 field observations, 2,421 yield measurements (i.e. berry weight, number of fruits and kg per hectare, among others), and 46,262 insect records from 49 commercial crops distributed around the globe. CropPol comprises 32 of the 87 leading global crops and commodities that are pollinator dependent. Malus domestica is the most represented crop (25 studies), followed by Brassica napus (22 studies), Vaccinium corymbosum (13 studies), and Citrullus lanatus (12 studies). The most abundant pollinator guilds recorded are honey bees (33.12% counts), bumblebees (18.65%), flies other than Syrphidae and Bombyliidae (13.76%), other wild bees (13.51%), beetles (11.47%), Syrphidae (4.86%), and Bombyliidae (0.06%). Locations comprise 32 countries distributed among European (70 studies), Northern America (59), Latin America and the Caribbean (27), Asia (22), Oceania (10), and Africa (7). Sampling spans three decades and is concentrated on 2001-05 (21 studies), 2006-10 (38), 2011-15 (87), 2016-20 (40). This is the most comprehensive open global data set on measurements of crop flower visitors, crop pollinators and pollination to date and we encourage researchers to add more datasets to this database in the future. No copyright restrictions are associated with the use of this dataset. Please cite this data paper when the data are used in publications and cite individual studies when appropriate.

Most cultivars of apple trees are highly dependent on insects for successful pollination and fruit production. In this study, we evaluated the insect diversity in apple orchards of southern Brazil and verified whether or not there is a relationship between the diversity of insect visitors and the characteristics (weight, seed number, and symmetry) of the fruits of 'Fuji' and 'Gala' apples produced by the orchards. We also evaluated the diversity of insects on flowering weeds within apple orchards and compared it with the apple flowers. Diversity of anthophilous insects was low, in general, and differed between the regions. Furthermore, regarding insect diversity, orchards were grouped by management system: organic orchards were more similar to each other than to conventional orchards. The insect diversity of weed flowers was higher than apple flowers, but insect abundance was greater on apple flowers, suggesting that weeds may increase insect diversity within apple orchards and may sustain pollinators. We found a positive effect of insect diversity on the number of seeds of 'Fuji' apples and of honeybee abundance on their weight, suggesting that honeybee management is important in the studied areas. In contrast, we found no significant effect of insect diversity and abundance on 'Gala' apple characteristics. Despite this, the analyses of the seeds of 'Gala' apples indicate that the orchards may suffer a pollination deficit, which could be overcome by improving insect pollination. These results reinforce previous findings that insect diversity is important for apple yield, but its influence varies with cultivar.