Article
To read the full-text of this research, you can request a copy directly from the authors.

Abstract

Global pollinator declines and land-use change can lead to pollination limitation with implications for agricultural productivity. Hand pollination is used in agricultural production as a technique to manually pollinate crops. But the prevalence of hand pollination, as well as benefits and costs, remain unknown. We systematically reviewed the literature for examples, methods, drivers, and economic motivations of hand pollination. Furthermore, we discuss the risks, constraints, and opportunities of hand pollination. We found evidence for 20 hand-pollinated crops, including minor but also economically important crops (e.g. apple, oil palm, cacao). The lack of pollinators was the most important reason for the application of hand pollination (50% of crops), while insufficient proportion or proximity of pollinizers (8% of crops) and skewed sex ratio or dichogamy (8% of crops) were second most important. The main economic motivations for practicing or recommending hand pollination were to increase fruit set, and/or fruit quality (78% of crops). Hand pollination is practiced in large- and small-scale farming, home gardens, and greenhouses. Opportunities of hand pollination are the control of pollen origin and quantity, pollination timing and frequency as well as independence from environmental fluctuations. Farmers can increase yields, improve fruit quality, avoid fruit abortion, increase employment, and secure subsistence food. The main constraints of hand pollination are high labor inputs, high material costs, and required skills. Major risks of hand pollination include management ignoring pollinator conservation, high food prices, over-pollination, labor accidents, and unfair labor. We conclude that in the face of global change, hand pollination allows improved control of pollination and is likely to increase in importance. The benefits of hand pollination need to outweigh the costs and fair labor is essential. Altogether, hand pollination can be a valuable tool for crop systems where pollinators are absent or are not reliable for sustaining high-quality crop production.

No full-text available

Request Full-text Paper PDF

To read the full-text of this research,
you can request a copy directly from the authors.

... However, more recently, regions where oil palm has been introduced have observed fluctuations in weevil populations and fruit set rates, while drivers of oil palm pollination variability are still little understood (Donough et al., 1996;Wahid and Kamarudin, 1997). The alternative to pollination ecosystem services historically has been hand pollination, which is labor and resource intensive (Wurz et al., 2021). The loss of these pollination services would have a significant impact on producers, especially smallholder farmers, who have fewer resources to implement hand pollination methods, and make up 40% of growers in the region of our study (Qaim et al., 2020). ...
... Coefficient estimates and their 95% confidence interval (CI) are reported in the logodds scale, with the open pollination treatment as the baseline. typical definition of pollination limitation (Wurz et al., 2021). However, because oil palm produces parthenocarpic fruit types from unpollinated flowers, the sum of the pollinated and unpollinated fruits can be used to estimate a theoretical maximum fruit set for each fruit bunch (Lecoustre and Reffye, 1987). ...
Article
Natural habitat plays a role in many agroecosystems as a source of pollination services and other ecological spillover, but these effects are largely unquantified in oil palm (Elaeis guineensis), a globally important crop linked to deforestation. In a field experiment in Sumatra, Indonesia, we manipulated floral visitor access to female oil palm inflorescences over a 100 m distance gradient from forest into oil palm and sampled insects with sticky traps placed above male and female inflorescences. Full exclusion of floral visitors decreased mean oil palm fruit set to 12%, demonstrating that insect pollination was necessary to maintain favorable fruit set and yield. Treatment group means of fruit set under open pollination (62%) and when excluding large (>1.4 mm diameter) organisms (72%), did not differ significantly from open pollination augmented with hand pollination (61%), suggesting no difference in pollen limitation. In contrast, when we examined change in fruit set with distance from forest, we found a significant trend of higher fruit set in oil palms closer to the forest when large organisms were excluded, which increased estimated fruit set at the forest edge to 87%, compared to open-pollinated palms (70%). This trend with distance from forest was absent when we fully excluded floral visitors, showing that the effect of forest was not likely due to an abiotic gradient (e.g., changing soil nutrients). Of the arthropod taxa collected from sticky traps, Drosophilidae (Diptera) and Gelechiidae (Lepidoptera) decreased and increased with distance from forest, respectively. The taxa Elaeidobius kamerunicus (Coleoptera: Curculionidae), Gelechiidae, and the families Thripidae and Phlaeothripidae (Thysanoptera) were abundant on both male and female inflores-cence sticky traps. Elaeidobius kamerunicus, an introduced oil palm pollinator, had the only significant relationship with fruit set. Our results confirm pollination by insects as a key ecosystem service for oil palm production. Although further work is needed to clarify the relationship between fruit set, biodiversity, and distance from forest, we speculate that excluding large organisms could have increased fruit set closer to forest by mediating interactions between pollinators, forest predators, and farm mesopredators. Understanding the relationships between nearby forest and pollination services could better connect oil palm production to its landscape context and associated biodiversity. This would be important for landscape-scale conservation planning that considers both the ecosystem service needs and ecological impacts of oil palm agriculture.
... these technologies are being marketed as eco-friendly alternatives to managed pollinators when wild pollination services are insuf cient, although they still need to be benchmarked against them for ef ciency and cost-effectiveness. There is always a lowtech fallback: hand-pollination by humans is still widespread [144], especially when labor costs are low [145]. Although this approach is largely unsustainable in the long term, it provides an alternative to ameliorate losses of wild or managed pollination services, or sudden changes in the cost-bene t balance of certain crops [144]. ...
... There is always a lowtech fallback: hand-pollination by humans is still widespread [144], especially when labor costs are low [145]. Although this approach is largely unsustainable in the long term, it provides an alternative to ameliorate losses of wild or managed pollination services, or sudden changes in the cost-bene t balance of certain crops [144]. ...
Article
Adequate pollination is fundamental to optimize reproduction and yield of most flowering plants, including many staple food crops. Plants depending on insect pollination rely heavily on many wild species of solitary and social bees, and declines or absence of bees often hampers crop productivity, prompting supplementation of pollination services with managed bees. Though honeybees are the most widely deployed managed pollinators, many high-value crops are pollinated more efficiently by bumblebees ( Bombus spp.), prompting domestication and commercial rearing of several species. This led to a blooming international trade that translocated species outside their native range, where they escaped management and invaded the ecosystems around their deployment sites. Here, we briefly review the history of bumblebee invasions and their main impacts on invaded ecosystems, and close by discussing alternatives to the use of commercially reared bumblebees to enhance crop pollination. As evidence of widespread negative effects on local ecosystems of bumblebee invasions builds up, bumblebee trade adds to the list of examples of "biological" strategies devised to solve agricultural problems that ended up being far from the "green," eco-friendly solutions they were expected to be.
... 1,5 In such situations, hand pollination can become a promising alternative for food security. 14 Advantages of hand pollination in the case of limited fruit set include high yields, the control of pollen origin and quantity, pollination timing and frequency, as well as independence from environmental fluctuations. 14 The concept of ecological intensification of agriculture has been introduced to mitigate current drivers of pollinator decline by promoting management practices such as intercropping, crop rotations, and reduced agrochemical use. ...
... 14 Advantages of hand pollination in the case of limited fruit set include high yields, the control of pollen origin and quantity, pollination timing and frequency, as well as independence from environmental fluctuations. 14 The concept of ecological intensification of agriculture has been introduced to mitigate current drivers of pollinator decline by promoting management practices such as intercropping, crop rotations, and reduced agrochemical use. 5,9 Successful agricultural measures to enhance biodiversity on farmland include diversifying crops and reducing field size, which can multiply biodiversity and multiple ecosystem services while sustaining high yields in both conventional and organic systems. ...
Article
Global environmental change is critically endangering plant-pollinator interactions, as shown in this issue of One Earth by Huang et al., who combine phenomenological models with empirical plant-pollinator networks. Losses of pollination services in agricultural landscapes also endanger global food security but meeting the challenge of better understanding and sustaining crop pollination needs new approaches and policies.
... Low natural fruit set (around 1%) has been reported for V. planifolia, even in Mexico, where vanilla is native and natural pollinators are present [55][56][57]. Therefore, hand pollination is required for fruit production and, since its emergence in the XIX century (see Section 2), was adopted worldwide and remains essential in vanilla culture [55,58]. Low rates of fructification under natural conditions were also observed in other species: V. humblotii (0.62-1.2%) [39]; V. ribeiroi (1.1%) [49]; V. bahiana (2.35%) [40]; V. pompona (2.42% and 5%) [41,57]; V. bosseri (3.96%) [37]; V. cristato-callosa (6.6%) [49]; V. poitaei (6.4%); V. dilloniana (14.5%); ...
Article
Full-text available
Vanilla is a worldwide cherished condiment, and its volatile market is associated with the so-called “vanilla crisis”. Even though only two species (Vanilla planifolia and V. × tahitensis) are cultivated on a large scale for commercial purposes, the Vanilla genus is comprised of 140 species. The present review article discusses the facets of this crisis, and vanilla crop wild relatives (WRs) are showcased as alternatives to overcome them. Historical, taxonomic, and reproductive biology aspects of the group were covered. Emphasis was given to the metabolic characterization of the vanilla crop WRs, highlighting their main chemical classes and the potential flavor descriptors. Many of these species can produce important flavor compounds such as vanillin, vanillic acid, and acetovanillone, among others. Overall, this review compiles valuable information that can help unravel new chapters of the history of this treasured product by evidencing the biotechnological potential of vanilla crop WRs.
... Moreover, for pollination studies we identified the aspect of pollination studied either as "mating system", "pollination success" (degree of pollen limitation/sufficiency), or "pollinator diversity" (pollinators/flower visitors of shea, or their foraging behaviour). Pollinators were classified based on Wurz et al. [81] ei- ther as "bees" (honeybees, stingless bees or other bees), "non-bee insects" (wasps, butterflies, beetles, flies and bugs), or "vertebrate pollinators" (mammals and birds). ...
Article
Full-text available
Vitellaria paradoxa (shea) has interannual variability in fruit yield patterns, which results in unpredictable export volumes. Research on factors accounting for this inconsistency is needed to manage tree stands for optimum yield, but existing studies on the topic have shown conflicting results. In order to synthesize research approaches used in examining determinants of shea reproductive success, and to identify research gaps, we reviewed the existing literature on the subject available in Scopus and Google Scholar from 2000 to 2021. Out of 119 primary research articles identified in our literature search, 40 articles met our predefined inclusion criteria. Geographically, most studies (75%) were conducted in West Africa, and six times as many studies used quantitative approaches compared with either qualitative or mixed method approaches. Fruiting emerged as the most studied aspect of shea reproductive biology (73% of studies), whereas less is known on floral biology and pollination. All studies that assessed the effect of agro-ecology, seasonality, pollination, and altitude reported significant effect of these factors on fruit yield. However, there were divergent outcomes on land use/management, dendrometry and parkland tree diversity on fruit yield. The majority of the studies examined single factor effects on yield for one flowering/fruiting season, which is a major weakness of the existing research. We recommended several strategies to improve the reliability of future studies on determinants of shea reproductive success, such as designing multi-factorial experiments to cater for extraneous variables, profiling land use history of the shea parkland and conducting experiments for multiple seasons.
... pollen spraying or use of a paint brush) and climatic differences could affect the success of artificial pollination (Castro et al., 2016). Hand pollination could suffer from the use of incompatible or otherwise less suitable or low-quality pollen, thus not realizing the full potential of fruit or seed set resulting in a potential underestimation of actual pollination deficits (Aizen & Harder, 2007;Garratt et al., 2021;Wu, Tscharntke, et al., 2021;Wurz et al., 2021). A gradual delivery of pollen by insects may be more effective for fertilizing ovules than the sudden deposition of artificially large amounts of pollen, which may clog stigmas (Ashman et al., 2004). ...
Article
Full-text available
Apple is one of the most widely cultivated fruit crops worldwide, and apple yield benefits from pollination by insects. The global decline in wild pollinator populations raises concern about the adequacy of pollination services in apple production. Here, we present a global meta‐analysis of pollination in apple. We assembled from the literature a dataset comprising results of 48 studies across five continents on fruit set and seed set in apple with insect pollination, artificial pollination and pollinator exclusion, and analysed the effects of explanatory factors such as variety and continent. Fruit set was on average 41% lower with open pollination than with artificial pollination, while seed set was 20% lower. These pollination deficits varied across continents and cultivars. Pollination deficits for fruit set were greatest in Asia (63%) followed by Europe (30%), whereas pollination deficits for seed set were greatest in Asia (47%) and South America (40%). Important differences in pollination deficit were also identified between cultivars but these differences were confounded with continent effects. Fruit set and seed set were 71% and 62% higher, respectively, when insects had open access to flowers than when they were artificially excluded, while results varied among cultivars. Synthesis and Applications. Globally, there are substantial contributions of pollinators to fruit set and seed set in apple, as well as considerable limitations in apple pollination services, particularly in Asia, Europe and South America. Several management strategies could be applied to reduce the pollination deficits in apple production: (1) conserving wild bees and enhancing their abundance and diversity, (2) using managed bees for pollination, (3) using varieties with low pollinator dependency, and/or (4) artificial pollination. These strategies should be tailored to the regional situation, considering the potential of landscapes for restoring wild pollinators, the acceptability of cultivated varieties for available pollinators, the acceptance in the market of self‐compatible varieties, and the costs of management, such as artificial pollination, pollinator conservation, beekeeping and planting self‐compatible varieties. Conservation of wild pollinators is preferred in regions with sufficient potential for wild pollinators as it contributes to biodiversity conservation and improves pollination in both crops and wild plants.
... Of course, the direct benefits of these animal trends for agricultural pollination will likely be tempered by detrimental effects of managed and introduced pollinators on native pollinators (see subsection 'Pollinator decline'). Third, increasing demand for pollination services or absence of pollinators in some cases has motivated the use of laborious hand-pollination (Wurz et al. 2021) or the more recent development of futuristic pollinating drones (Potts et al. 2018). Nevertheless, these artificial pollination techniques are not as costeffective in practice as natural pollination and for many crops might not replace the quality and stability of the pollination services provided by diverse pollinator assemblages (see subsection 'Wild pollinators are essential for maintaining high yields'). ...
Article
Full-text available
ABSTRACT. Mounting evidence shows that pollinators are declining as a result of widespread environmental degradation. This loss raises concerns that a global pollination crisis could threaten the human food supply by decreasing crop yield and even promote famine under a hypothetical scenario of total pollinator extinction. This catastrophic possibility has prompted intense interest from scientists, politicians and the general public. However, three lines of evidence do not support such an apocalyptic scenario. First, even though the abundance and diversity of wild pollinators are declining worldwide, the global population of managed honey-bee hives has increased by ~80% since the early 1960s. Second, agricultural production would decrease by <10% in the total absence of bees because relatively few crops are completely pollinator dependent. Lastly, despite widespread pollination deficits, current evidence is inconsistent with deceleration in yield growth with increasing pollinator dependence at a global scale, probably due to improvements in crop breeding and external agricultural subsidies. Overall, this evidence refutes simplistic claims of human starvation caused by a hypothetical total pollinator extinction. Nevertheless, pollination problems may loom. Although pollinators are responsible for a minor fraction of global agriculture production, this fraction has increased ~600% since 1961, greatly outpacing human population growth and the growth of the global population of managed honey bees. This large production increase is explained to a considerable extent by the rapid expansion of pollinator-dependent monocultures at the expense of natural and diverse agricultural habitats. By driving pollinator decline, this land-use transformation could worsen pollination deficits and promote further crop expansion given sustained market demands. Therefore, although the human food supply is not currently subject to a global pollination crisis, a spiraling positive-feedback between the impacts of agriculture expansion and pollinator decline on crop yield could accelerate precipitous biodiversity loss by promoting further habitat destruction and homogenization.
... The coefficient of the variable representing hand pollination also had a negative relationship with profit inefficiency. Thus, farmers who engaged in hand pollination had higher profit efficiencies than those who did not [81]. Hand pollination is a recent policy by the government aimed at improving cocoa output in the country. ...
Article
The study examined the effect of hybrid cocoa seedling adoption on the profit efficiency of cocoa production in Ghana using cross-sectional data collected from 150 farming households in the Wassa Amenfi West district of Ghana. Cragg's Double Hurdle model, stochastic frontier profit function and propensity score matching were the methods of analysis. The results showed that whereas tree density and age of farm had negative influences on hybrid cocoa seedling adoption, farming experience exerted a positive effect. Also, the intensity of adoption of hybrid cocoa seedling was influenced by being a male farmer, tree density, access to extension as well as access to technological information. The mean estimated profit efficiency was 89.9% and this was positively influenced by male gender, hand pollination, age of cocoa tree, access to technological information and education even though farming experience exerted a negative effect. Finally, the study revealed that hybrid cocoa seedlings adopters are 0.101 more profit efficient than non-adopters. Farmers are therefore encouraged to adopt hybrid cocoa seedlings in their cocoa farms. It is also important for government to put measures in place to introduce agricultural programmes on radio and other media to enable farmers get access to technological information.
... In some highly pollinator-dependent crops, lack or mismatch of pollinators forces artificial pollination, supplementary management of bees, or wind / self-pollination are required to increase seed setting in production (Westerkamp and Gottsberger, 2000;Dai et al., 2016;Abrol, 2011c;Wizenberg et al., 2020;Wurz et al., 2021). Pollination affects the temporal and spatial stability of crop pollination during flowering, thereby affecting fruit / seed growth, seed setting and quality, especially commercial flowering crops grown on a large scale (Stein et al., 2017;Bashir et al., 2017;Samnegård et al., 2019;Sáez et al., 2019;Jing et al., 2021). ...
Article
Insufficient pollination reduces the fruit and seed setting rate and limits the chance of outcrossing in crop plants that are highly dependent on insect pollination, thus affecting the quality and growth rate of progenies. To investigate the effect of pollination methods on the fruit growth rate, fruit yield, oil yield and seed oil quality, four pollination methods, such as (1) in cages with honeybees (Apis mellifera L.), the control in cages with (2) hand pollination, (3) wind pollination, and (4) self-pollination were used to pollinate the flowers of oil tree peony (Paeonia ostii T. Hong et J.X. Zhang). Results showed that the mean growth rate and cumulative growth rate of fruit diameter, follicle length and diameter pollinated by honeybees were significantly higher than that of the control group (hand, wind and self-pollination). Fruit development ratio, seed setting rate and the number of seeds per fruit pollinated by honeybees were significantly higher than self-pollination. Moreover, pollination by honeybees increased yield per fruit by 56.28%, 59.42% and 126.27% compared to the hand, wind and self-pollination, respectively. Compared with hand pollination, the oil yield of honeybee-pollinated tree peony increased by 12.24%. However, the total unsaturated fatty acidcontent of seed oil was not significantly changed with different pollination methods. Our study demonstrated that bee pollination is essential to reach rapid fruit development and high seed yield in oil tree peony.
... Griggs and Vansell (1949) first mentioned the use of honey bee-collected pollen for artificial pollination of deciduous fruit trees in the first half of the 20th Century. To date, hand pollination is known to have been employed for 20 different crops (Wurz et al., 2021). Artificial pollination with blowers and vibrating devices was an established method for the pollination of tomatoes grown under cover that, because it was labour-intensive and expensive, has nowadays largely been replaced by managed bumble bees (Velthuis and van Doorn, 2006). ...
Article
Cultivation of pollinator-dependent crops has expanded globally, increasing our reliance on insect pollination. This essential ecosystem service is provided by a wide range of managed and wild pollinators whose abundance and diversity are thought to be in decline, threatening sustainable food production. The Western honey bee (Apis mellifera) is amongst the best-monitored insects but the state of other managed pollinators is less well known. Here, we review the status and trends of all managed pollinators based on publicly accessible databases and the published literature. We found that, on a global scale, the number of managed A. mellifera colonies has increased by 85% since 1961, driven mainly by Asia. This contrasts with high reported colony overwinter mortality, especially in North America (average 26% since 2007) and Europe (average 16% since 2007). Increasing agricultural dependency on pollinators as well as threats associated with managing non-native pollinators have likely spurred interest in the management of alternative species for pollination, including bumble bees, stingless bees, solitary bees, and flies that have higher efficiency in pollinating specific crops. We identify 66 insect species that have been, or are considered to have the potential to be, managed for crop pollination, including seven bumble bee species and subspecies currently commercially produced mainly for the pollination of greenhouse-grown tomatoes and two species that are trap-nested in New Zealand. Other managed pollinators currently in use include eight solitary bee species (mainly for pollination services in orchards or alfalfa fields) and three fly species (mainly used in enclosures and for seed production). Additional species in each taxonomic category are under consideration for pollinator management. Examples include 15 stingless bee species that are able to buzz-pollinate, will fly in enclosures, and some of which have a history of management for honey production; their use for pollination is not yet established. To ensure sustainable, integrated pollination management in agricultural landscapes, the risks, as well as the benefits of novel managed pollinator species must be considered. We,
Chapter
Pollinators are crucial to biodiversity conservation, ecosystem protection, agriculture, and climate change adaptation. Crop pollination has a global annual value of US $235–577 billion. In Morocco, insect pollinators contributed USD $1235.06 M to main crop production, accounting for 8.52% of total agricultural GDP. In response to climate change, the geographical range and phenology of insect pollinators shift, their interactions with plants and other taxa are altered, and in some cases, pollination services are reduced. As a result, a decrease in pollination activity clearly compromises adequate crop production for a growing human population. Consequently, other plant species that rely on insect pollinators for outcrossing may also face extinction, putting human health and crop production at risk. The effects of elevated temperature on flowering plants and insect pollinators may have an impact on pollinator floral resources and plant pollination success, respectively. Plant reactions to global warming, irregular rainfall, and other environmental conditions may include altered blooming, nectar, and pollen production, as well as changes in floral resource availability, distribution, visitation quality, pollinator reproductive output, and threat from insect pests and diseases. Pollinator responses, such as changes in foraging spatial scale, body size, and lifetime, may also influence pollen flow patterns and pollination efficiency. Climate change must be considered because it has the potential to have a substantial influence on pollinator populations, resulting in lower productivity and imperiling food security. Efforts should therefore be directed toward the preservation of pollinators. One solution for improving agriculture in Morocco and rising its resilience to climate change is to take an integrated agroecological and socioeconomic approach to pollinator conservation. Thus, monitoring the status and trends of insect pollinators and assessing pollination functions and services are needed to address the potential effects of climate change and inform adaptive management of ecosystems that could help ensure food security and agricultural sustainability. Recommended actions include as well doing more research to fill knowledge gaps, expanding studies to cover a wider range of pollinators, and promoting coordinated follow-up work at the local, regional, and national levels.
Chapter
Mit dem Szenario „Economy First – Business as usual” wird eine Zukunft beschrieben, die aktuelle Entwicklungen pointiert und geradlinig in die Zukunft extrapoliert. Die Segregation verschiedener Bevölkerungsteile dominiert in diesem Szenario. So konnten zwar die katastrophalen Klimafolgen abgewendet werden, dabei sind soziale und politische Gleichberechtigung wirtschaftlicher Entwicklung zum Opfer gefallen. Einkommensschwache Bevölkerungsteile leben in den veralteten, energetisch ineffizienten Innenstädten, während sich wohlhabende Teile der Gesellschaft in sogenannten Gated Communities absondern. Diese werden zum Großteil von Großkonzernen finanziert, verwaltet und befinden sich auf den technisch aktuellsten Stand. Diese Nähe der Unternehmen drückt sich auch an der Einflussnahme auf wichtige gesellschaftliche Bereiche aus. So nehmen Unternehmensvertreter:innen nicht nur direkten Einfluss auf politische Entscheidungsprozesse, sondern auch auf die Ausgestaltung des Bildungssystems. Damit ist die Hoffnung verbunden, dass durch Aufstiegschancen Einzelner der Unmut in der Gesellschaft besänftigen lässt.
Article
Full-text available
Resolving ecological-economic trade-offs between biodiversity and yields is a key challenge when addressing the biodiversity crisis in tropical agricultural landscapes. Here, we focused on the relation between seven different taxa (trees, herbaceous plants, birds, amphibians, reptiles, butterflies, and ants) and yields in vanilla agroforests in Madagascar. Agroforests established in forests supported overall 23% fewer species and 47% fewer endemic species than old-growth forests, and 14% fewer endemic species than forest fragments. In contrast, agroforests established on fallows had overall 12% more species and 38% more endemic species than fallows. While yields increased with vanilla vine density and length, non-yield related variables largely determined biodiversity. Nonetheless, trade-offs existed between yields and butterflies as well as reptiles. Vanilla yields were generally unrelated to richness of trees, herbaceous plants, birds, amphibians, reptiles, and ants, opening up possibilities for conservation outside of protected areas and restoring degraded land to benefit farmers and biodiversity alike.
Article
Full-text available
Objective Date palm is mostly cultivated in Western Asia and North Africa and is the main wealth for the people of these regions. Traditional date palm crown access via manual climbing, as the main activity in date fruit production, suffers from occupational hazards. Mitigation of these problems through interventions or new designs initially needs to complete knowledge of safety and health aspects and relationships between them and characters of date palm climbers. This study provided detailed information about this concern. Methods A questionnaire consisting of personal, operational, safety, satisfaction, financial and ergonomic demographics was used for data collection. 117 climbers participated in the study. Nonparametric correlations using Spearman’s coefficient and logistic regressions investigated the linkage between characters obtained by the questionnaire. Results The annual mortality rate of falls from height was calculated by 3.4 per one thousand men. Fall was a major challenge in traditional date palm crown access and its rate was highly greater in comparison with the estimation of International Labor Office (ILO) about fatal agricultural injuries. Safety and health condition was the main contributing factor in the status of date palm climbing and was significantly linked to job satisfaction. Safety risk-taking and non-awareness of technology had a significant linkage with together (r = − 0.195, p = 0.035). Safety risk-taking, also, had significant correlations with discomfort in back (r = − 0.201, p = 0.030). Regressions showed heavier climbers (> 75 kg) were expected about 4.3 (1/0.230) times than more lightweight ones to have an upper leg discomfort with high severity relative to low severity (p = 0.018). Conclusion Obesity, senescence, and awareness of technology as three personal characteristics of climbers need to be addressed. Future strategies are required to improve the safety condition of climbing and manage the workforces as well as governmental decision making to address the financial aspects of climbers for sustainable date production and reduction in reasons causing unemployment. Considering current status and modification of the present tool and equipment is recommended.
Article
Full-text available
Bees provide key pollination services for a wide range of crops. Accumulating evidence shows the effect of semi-natural habitats at the landscape level and local management practices on bee diversity in fields. However, most of the evidence is derived from studies in North America and Europe. Whether this paradigm is applicable in China, which is characterized by smallholder-dominated agricultural landscapes, has rarely been studied. In this study, we aimed to investigate how bee diversity affected apple production, and how landscape and local variables affected bee diversity and species composition on the Northern China Plain. The results showed that bees significantly increased apple fruit set compared to bagged controls. Wild bee diversity was positively related to apple seed numbers. Higher seed numbers reduced the proportion of deformed apples and thus increased fruit quality. Wild bee abundance was positively correlated with flowering ground cover, and both the abundance and species richness of wild bees were positively affected by the percentage of semi-natural habitats. We conclude that apple quality can benefit from ecological intensification comprising the augmentation of wild bees by semi-natural habitats and flowering ground cover. Future pollination management should therefore reduce the intensification level of management at both the local and landscape scales.
Article
Full-text available
Interspecific OxG hybrids of African palm Elaeis guineensis Jacq. and the American palm Elaeis oleifera Cortes produce high-oleic palm oil (HOPO) with low saturated fatty acid content. OxG hybrids are highly productive, grow slowly, and are resistant to bud rot disease. However, OxG hybrid pollen presents low viability and germinability, so assisted pollination is a must. Hybrids can produce parthenocarpic or seedless fruits, with the exogenous application of plant growth regulators. Thus, naphthalene acetic acid (NAA) effects on parthenocarpic fruits induction, bunch formation, and oil quality were evaluated. The OxG hybrid Coari x La Mé was used. NAA doses, frequency, number of applications, and the phenological stages for the treatments were defined. A total dose of 1200 mg L-1 NAA applied three or four times produced bunches with better fruit set, similar average bunch weight, and oil to dry mesocarp than those obtained with assisted pollination. At a semi-commercial scale, 1200 mg L-1 NAA induced bunches that consisted of 93% or more of seedless fruits. Bunch number (2208 +/- 84 versus 1690 +/- 129) and oil to bunch (32.2 +/- 0.7 versus 25.3 +/- 0.8) were higher in the NAA induced bunches than in the assisted pollination. However, the average bunch weight was lower (12.2+/- 0.4 versus 14.9 +/- 0.6). NAA increased oil to bunch in 36% (8.7 +/- 0.1 versus 6.4 +/- 0.3). Thus, with this technology, it is plausible to reach more than 10 tons per hectare per year of HOPO. Potentially, without increasing the planted oil palm area, OxG hybrids and NAA applications could alone meet the world’s fats and oil demands.
Article
Full-text available
Pollination by insects is critical for the production of many crops worldwide. Crop cultivars vary in a number of traits, but their differing pollination requirements are often overlooked. Kiwifruit (Actinidia chinensis) is reliant on pollen movement between male and female plants, but there has been disagreement in the literature about what its pollination requirements are. Additionally, there is little information about how time-of-day might affect fruit and seed set, and how this may alter the efficacy of pollination management strategies. In this study, we compare the pollination requirements of A. chinensis var. deliciosa ‘Hayward’ (a hexaploid green-fleshed variety) and A. chinensis var. chinensis ‘Zesy002’ (a tetraploid gold-fleshed variety). We find that ‘Zesy002’ requires fewer pollen grains than ‘Hayward’ for full seed set. Kiwifruit appears to be equally able to set fruit at any time of the day, meaning that insects which forage outside the peak hours of 0900–1500 h may play an important supporting role in fruit production, and that artificial pollination could profitably be applied into the evening hours rather than being limited to the period of peak pollinator activity.
Preprint
Full-text available
Pollinator decline has attracted global attention, and substantial efforts are underway to respond, through national pollinator strategies and action plans. These policy responses require clarity on what is driving pollinator decline, and what risks it generates for society, in different parts of the world. Using a formal expert elicitation process, we evaluated relative regional and global importance of eight pressures driving pollinator decline, and ten consequent risks to human well-being. Our results indicate that global policy responses should focus on reducing pressure from changes in land cover and configuration, land management, and pesticides, as these were considered very important drivers in most regions. We quantify for the first time how the importance of drivers, and risks from pollinator decline, differ among regions. For example, losing access to managed pollinators was only considered a serious risk to people in North America, whereas yield instability in pollinator-dependent crops, classed as a serious or high risk in four regions, presented only moderate risk in Europe and North America. Overall, perceived risks were substantially higher in the Global South. Despite extensive, research on pollinator decline, our analysis reveals considerable scientific uncertainty about what this means for human society.
Article
Full-text available
The main objective of the research study was to compare a locally developed date palm pollination machine to manual pollination during two successive seasons. Two pressures were used to operate the machine. The parameters measured were, rate of work, pollen application rate, crop yield and cost of pollination. The results indicated that the field capacity (rate of work) of the pollination machine was 18 tree/hr, while for the manual pollination it was 5 tree/hr. The machine pollen application rate was 0.5-1 gm/tree as compared to manual pollination which consumed higher amount of pollen 8 gm/tree. There was no significant difference between the effect of using the three methods of pollination on physical and chemical characteristics of date fruits. There was significant effect of treatments on quantity of date yield in the two seasons for the three methods of pollination at 5% level of significance. The pollination machine at high pressure produced higher yield than other treatments which were 605 kg, 1206 kg for the two seasons respectively, while the lowest yield was recorded by manual pollination as 233 kg and 818 kg for the two seasons in sequence. The pollination cost of the machine was 9.1 SDG /tree which was less than the manual pollination that costs 60 SDG /tree. The manual pollination needed two labors to pollinate 200 trees per season, while mechanical pollinator needed one operator to pollinate 760 trees per year. The pollination machine reached up to 10 meters in height. In addition, considerable reduction of time requirements, and pollination cost were observed. It was concluded that the pollination machine is highly reliable and efficient in control over pollen application rate, thus reducing pollen loss to minimum, saving cost and time and overcoming defects associated with manual pollination.
Article
Full-text available
We discuss comparative static partial equilibrium approaches for large-scale monetary valuations of animal-mediated crop pollination. These approaches rely upon reported crop production values, own-price elasticities of demand and experimentally found dependence ratios that express crop-specific yield shares due to pollinators. We dismiss the established long-term approach given the difficulty of anticipating the adaptation of the bioeconomic system to changes of pollinator abundance. Instead, we suggest another more parsimonious method, which assesses the short-term welfare effects following a sudden change in pollinator abundance. Using 2016-2018 data on agricultural production, we estimate the worldwide welfare effects due to a pollinator collapse for a range of plausible own-price elasticities, both from short-term and long-term perspectives. For the former we also simulate a global recovery scenario. Depending on the overall price elasticity assumed, the short-term effects of a total pollinator loss lie between 1 and 2 % of global GDP. We also apply the different valuation approaches to more detailed German 2006-2016 crop production data, where we account for crop-specific demand. As the reported dependence ratios vary in wide ranges, we rely upon stochastic simulations to obtain likely distributions of the German welfare effects.
Article
Full-text available
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. An insufficient amount of pollen transfer by pollinators (pollen limitation) could reduce plant reproduction in human-impacted landscapes. Here the authors conduct a global meta-analysis and find that pollen limitation is high in urban environments and depends of plant traits such as pollinator dependency.
Article
Full-text available
Most of the world’s crops depend on pollinators, so declines in both managedand wild bees raise concerns about food security. However, the degree towhich insect pollination is actually limiting current crop production ispoorly understood, as is the role of wild species (as opposed to managed hon-eybees) in pollinating crops, particularly in intensive production areas. Weestablished a nationwide study to assess the extent of pollinator limitation inseven crops at 131 locations situated across major crop-producing areas ofthe USA. We found that five out of seven crops showed evidence of pollinatorlimitation. Wild bees and honeybees provided comparable amounts of pollina-tion for most crops, even in agriculturally intensive regions. We estimated thenationwide annual production value of wild pollinators to the seven crops westudied at over $1.5 billion; the value of wild bee pollination of all pollinator-dependent crops would be much greater. Our findings show that pollinatordeclines could translate directly into decreased yields or production formost of the crops studied, and that wild species contribute substantially topollination of most study crops in major crop-producing regions.
Article
Full-text available
Shea Vitellaria paradoxa trees bear fruit and seeds of considerable economic, nutritional and cultural value in the African Sudano‐Sahelian zone. In much of West Africa, shea exists within an agroforestry system referred to as ‘parkland’, where social changes, including migration, have resulted in expanding areas of crop cultivation, reductions in both the area of fallow land and the duration of fallow periods, and reduced diversity of habitats and woody species. Shea benefits strongly from pollination by bees and the loss of Parkland biodiversity may reduce the availability of pollinators, leading to pollen limitation and reductions in fruit yields. We investigated whether shea trees in southern Burkina Faso experienced pollination limitation, and whether local‐ and landscape‐scale diversity were linked to visitation by bees, the degree of limitation observed and the weight of fruit produced. Honeybees Apis mellifera were observed more frequently in diverse sites, whereas non‐Apis species were generally widespread but visited trees in greater numbers at diverse sites. We found that shea fruit production was significantly limited due to lack of pollination and that the degree of pollination limitation was greater in sites with lower levels of tree and shrub diversity. Synthesis and applications. Sites with greater diversity of tree and shrub species had more bee visits and less extreme pollination limitation than less diverse sites, indicating that small‐scale diversity is associated with more efficient pollination services. Consequently, shea yields are likely to benefit from retention of a range of different tree and shrub species in parklands. We recommend that when fallows are cleared for cultivation, such beneficial plants are retained within cultivated fields, and that measures to conserve pollinators in the region should target both A. mellifera and non‐Apis bee species. Les arbres du karité Vitellaria paradoxa portent des fruits et des graines qui ont une importance considérable au niveau économique, nutritif et culturel dans la zone Soudano‐Sahélienne de l'Afrique. Le karité fait partie d'un système agroforestier dit ‘parkland’ ou savane arborée, là où, suite aux changements sociaux, la surface cultivée a augmenté alors que les jachères ont vu leur surface et durée diminuer entrainant une réduction de la diversité des habitats et des espèces ligneuses. Le karité bénéfice fortement de la pollinisation par les abeilles, et il se peut que la perte de diversité dans les savanes arborées réduise la disponibilité des insectes pollinisateurs, ce qui mène à la limitation de la pollinisation et aux réductions des rendements de fruits. Ici, nous étudions si les arbres du karité dans le sud du Burkina Faso sont affectés par la limitation de pollinisation, et s'il y a un lien entre la diversité au niveau du site ou du paysage et le niveau de limitation de pollinisation, la présence des abeilles et le poids des fruits rendus par les arbres. Nous avons trouvé que les Apis mellifera visitent plus souvent, et les autres espèces d'abeilles sauvages (particulièrement les Hypotrigona ruspoldii) visitent plus abondamment, les karités dans les sites où la diversité des espèces ligneuses est plus grande. En plus, nous avons trouvé que la production de fruit du karité est significativement limitée par le manque de pollinisation, et que la limitation est plus importante dans les sites où la diversité des espèces ligneuses est plus petite. Synthèse et applications. Nous concluons qu'il est probable que les rendements de karité soient améliorés par la préservation d'une diversité d'arbres et d'arbustes dans le paysage, et nous recommandons que lorsque les jachères sont cultivées, ces plants avantageux soient préservés. Dans le futur, la gestion devrait soutenir la conservation des A. mellifera ainsi que les abeilles d'autres espèces. Sites with greater diversity of tree and shrub species had more bee visits and less extreme pollination limitation than less diverse sites, indicating that small‐scale diversity is associated with more efficient pollination services. Consequently, shea yields are likely to benefit from retention of a range of different tree and shrub species in parklands. We recommend that when fallows are cleared for cultivation, such beneficial plants are retained within cultivated fields, and that measures to conserve pollinators in the region should target both Apis mellifera and non‐Apis bee species.
Article
Full-text available
The fruit set in monovarietal ‘Manzanillo’ olive orchards is significantly increased under cross-pollination. This response lead to pollination designs including pollinizer selection, the number of pollinizer trees per hectare and their distribution in the orchard. However, the assignment of a substantial area to pollinizers of lesser commercial value might decrease profits. The strong influence of variable climates on the overlap of the blooming phenology of ‘Manzanillo’ and its pollinizer, and on pollen production and dispersal, are also notable risks. Artificial pollination is a feasible alternative to pollination designs, especially for wind-pollination crops such as olives. Here, we present the effects of treatments with different number (zero, one, two or four) of mechanical applications of ‘Barouni’ pollen on fruit set, size, yield, and cost–benefit ratios in heavy- and light-flowering trees of ‘Manzanillo’ trees situated in monovarietal orchards in Sonora, Mexico. Our results showed that, in “on” years (seasons where most trees display abundant flowering), a larger number of cross-pollen artificial applications increased more the final fruit set, yield and, hence, the profits. Fruit size was scarcely affected by the number of applications, although treatments with lower fruit sets had a higher proportion of large-sized fruit and less fruit of petite size. Despite its higher costs, the higher increase in yield made it more profitable to apply cross-pollination four times throughout the blooming period. On the other hand, no significant differences were observed among treatments, regardless of the number of pollinations, in the “off” season (the season in which most trees had a light flowering level).
Article
Full-text available
Population declines of pollinators constitute a major concern for the fate of biodiversity and associated ecosystem services in a context of global change. Massive declines of pollinator populations driven by habitat loss, pollution, and climate change have been reported, whose consequences at community and ecosystem levels remain elusive. We conducted a mathematical modeling and computer simulation study to assess the dynamic consequences of pollinator declines for the biodiversity of plants and pollinators. Specifically, we evaluated the effects of increased mortality and decreased carrying capacity of specialist vs. generalist and effective vs. ineffective pollinators visiting specialist vs. generalist plants on long‐term community biomass and species persistence. Our results reveal that increased larval mortality and increased competition for space among larvae had the greatest impacts on the decline of pollinator diversity. In contrast, the largest sustained decreases in pollinator biomass were driven by increased adult mortality in spite of a small increase in pollinator species persistence. Decreased pollinator diversity led in turn to decreased plant diversity. Attacking pollinators with high degree and connected mostly to low‐degree plants produced the greatest losses of plant diversity. Pollinator effectiveness had no noticeable effect on persistence. Our results illuminate our understanding of the consequences of pollinator declines for the maintenance of biodiversity.
Article
Full-text available
Urban expansion is considered to be one of the main threats to global biodiversity yet some pollinator groups, particularly bees, can do well in urban areas. Recent studies indicate that both local and landscape-level drivers can influence urban pollinator communities, with local floral resources and the amount of impervious cover in the landscape affecting pollinator abundance, richness and community composition. Urban intensification, chemicals, climate change and increased honey bee colony densities all negatively affect urban pollinators. Maintaining good areas of habitat for pollinators, such as those found in allotments (community gardens) and domestic gardens, and improving management approaches in urban greenspace and highly urbanised areas (e.g. by increasing floral resources and nesting sites) will benefit pollinator conservation. Opportunities for pollinator conservation exist via multiple stakeholders including policymakers, urban residents, urban planners and landscape architects.
Article
Full-text available
Understanding diversity in flower-visitor assemblages helps us improve pollination of crops and support better biodiversity conservation outcomes. Much recent research has focused on drivers of crop-visitor diversity operating over spatial scales from fields to landscapes, such as pesticide and habitat management, while drivers operating over larger scales of continents and biogeographic realms are virtually unknown. Flower and visitor traits influence attraction of pollinators to flowers, and evolve in the context of associations that can be ancient or recent. Plants that have been adopted into agriculture have been moved widely around the world and thereby exposed to new flower visitors. Remarkably little is known of the consequence of these historical patterns for present-day crop-visiting bee diversity. We analyse data from 317 studies of 27 crops worldwide and find that crops are visited by fewer bee genera outside their region of origin and outside their family's region of origin. Thus, recent human history and the deeper evolutionary history of crops and bees appear to be important determinants of flower-visitor diversity at large scales that constrain the levels of visitor diversity that can be influenced by field- and landscape-scale interventions.
Article
Full-text available
Food security and the sustainability of native ecosystems depends on plant-insect interactions in countless ways. Recently reported rapid and immense declines in insect numbers due to climate change, the use of pesticides and herbicides, the introduction of agricultural monocultures, and the destruction of insect native habitat, are all potential contributors to this grave situation. Some researchers are working towards a future where natural insect pollinators might be replaced with free-flying robotic bees, an ecologically problematic proposal. We argue instead that creating environments that are friendly to bees and exploring the use of other species for pollination and bio-control, particularly in non-European countries, are more ecologically sound approaches. The computer simulation of insect-plant interactions is a far more measured application of technology that may assist in managing, or averting, ‘Insect Armageddon' from both practical and ethical viewpoints.
Article
Full-text available
The global increase in the proportion of land cultivated with pollinator‐dependent crops implies increased reliance on pollination services. Yet agricultural practices themselves can profoundly affect pollinator supply and pollination. Extensive monocultures are associated with a limited pollinator supply and reduced pollination, whereas agricultural diversification can enhance both. Therefore, areas where agricultural diversity has increased, or at least been maintained, may better sustain high and more stable productivity of pollinator‐dependent crops. Given that >80% of all crops depend, to varying extents, on insect pollination, a global increase in agricultural pollinator dependence over recent decades might have led to a concomitant increase in agricultural diversification. We evaluated whether an increase in the area of pollinator‐dependent crops has indeed been associated with an increase in agricultural diversity, measured here as crop diversity, at the global, regional, and country scales for the period 1961–2016. Globally, results show a relatively weak and decelerating rise in agricultural diversity over time that was largely decoupled from the strong and continually increasing trend in agricultural dependency on pollinators. At regional and country levels, there was no consistent relationship between temporal changes in pollinator dependence and crop diversification. Instead, our results show heterogeneous responses in which increasing pollinator dependence for some countries and regions has been associated with either an increase or a decrease in agricultural diversity. Particularly worrisome is a rapid expansion of pollinator‐dependent oilseed crops in several countries of the Americas and Asia that has resulted in a decrease in agricultural diversity. In these regions, reliance on pollinators is increasing, yet agricultural practices that undermine pollination services are expanding. Our analysis has thereby identified world regions of particular concern where environmentally damaging practices associated with large‐scale, industrial agriculture threaten key ecosystem services that underlie productivity, in addition to other benefits provided by biodiversity. Increasing cultivation of pollinator‐dependent crops has placed a stress on global pollination capacity, which could have been ameliorated by a concomitant increase in agricultural diversification. However, this study reports a relatively weak and decelerating rise in agricultural diversity over time that was largely decoupled from the strong and continually increasing trend in agricultural dependency on pollinators. Particularly worrisome is a rapid expansion of pollinator‐dependent monocultures in several countries of the Americas and Asia that has resulted in a decrease in agricultural diversity. In these regions, reliance on pollinators is increasing, yet agricultural practices that undermine pollination services are expanding.
Article
Full-text available
Pollinators are key agents for ecosystems and humankind concerning biodiversity, agriculture, climate change adaptation and all other ecosystem services. Particularly in industrialized countries pollinator diversity is in decline. The bulk of research is on entomological or plant‐pollinator network related topics, but the broad range of impacts of pollinator loss on coupled human and natural systems is not yet studied. As 87% of all flowering plants depend on pollinators, they are basic for all ecosystem services to some extent. Therefore, pollinator loss might cause simultaneous degradation of ecosystem services inducing counterproductive human responses and interlinked poverty spirals. The interaction of climate change, a main risk factor for pollinators and unadvised human responses to pollinator decline are rarely studied. Tipping points of pollinator loss are not yet identified. Can counterproductive human responses to pollinator deficiency upscale pollinator decline towards a Pollinator‐loss Syndrome in the course of climate change? The article argues for research on the impacts of pollinator loss on other ecosystem services, useful and counterproductive human strategies on pollinator‐loss induced degradation and the integration of pollinator protection into all terrestrial restoration efforts. This article is protected by copyright. All rights reserved.
Article
Full-text available
The foraging activities of insect visitors on cucumber (Cucumis sativus L.) were studied. The insect visitors in decreasing order of abundance were: Formica sp.>Apis mellifera>Apis cerana>syrphids≥Apis dorstata. The activity of insects was peaked at 08.00-09.00 am. The foraging behaviour of A. mellifera was also studied. The bees spent significantly more time per flower during morning hours (sec/flower) and foraged significantly fewer flowers (7.9 flowers/min) compared to evening hours. There were significantly more nectar foragers (6.03/m²/10 min) than pollen foragers (5.16/m²/10 min). Most pollen foragers were observed during morning hours (6.59/m²/10 min) whereas nectar foragers were most active during noon hours (6.63/m²/10 min). Highest fruit set was observed in hand pollination (70.68%). Percentage of misshapen fruits was maximum in without honey bee pollination (24.35%). Without honey bee pollination resulted in significantly lowest percentage of healthy fruits (75.25%). Hand pollination ranked highest among the three forms of pollination in respective of fruits (985.13 g), number of seeds per fruit (425.22), fruit diameter (27.1 cm), fruit length (26.7 cm) and weight of 1000-seeds (28.64 g). J. Biodivers. Conserv. Bioresour. Manag. 2018, 4(2): 81-88
Chapter
Full-text available
This chapter presents current knowledge of observed and projected impacts from extreme weather events, based on recorded events and their losses, as well as studies that project future impacts from anthropogenic climate change. The attribution of past changes in such impacts focuses on the three key drivers: changes in extreme weather hazards that can be due to natural climate variability and anthropogenic climate change, changes in exposure and vulnerability, and risk reduction efforts. The chapter builds on previous assessments of attribution of extreme weather events, to drivers of changes in weather hazard, exposure and vulnerability. Most records of losses from extreme weather consist of information on monetary losses, while several other types of impacts are underrepresented, complicating the assessment of losses and damages. Studies into drivers of losses from extreme weather show that increasing exposure is the most important driver through increasing population and capital assets. Residual losses (after risk reduction and adaptation) from extreme weather have not yet been attributed to anthropogenic climate change. For the Loss and Damage debate, this implies that overall it will remain difficult to attribute this type of losses to greenhouse gas emissions. For the future, anthropogenic climate change is projected to become more important for driving future weather losses upward. However, drivers of exposure and especially changes in vulnerability will interplay. Exposure will continue to lead to risk increases. Vulnerability on the other hand may be further reduced through disaster risk reduction and adaptation. This would reduce additional losses and damages from extreme weather. Yet, at the country scale and particularly in developing countries, there is ample evidence of increasing risk, which calls for significant improvement in climate risk management efforts.
Article
Full-text available
China is one of most biodiverse countries in the world, containing at least 10% of all angiosperm species. Therefore, we should anticipate a diverse, pollinator fauna. China also has a long history of applied ethnobiology, including a sustainable agriculture based on apiculture and plant-pollinator interactions. However, the science of pollination ecology is a far younger sub-discipline in China, compared to in the West. Chinese studies in pollination ecology began in the 1970s. For this review, we compiled a complete reference database (>600 publications) of pollination studies in China. Using this database, we identified and analyzed gaps and limitations in research on the pollination systems of native and naturalized species. Specifically, we asked the following questions: 1) What do we know about the pollination systems of native, Chinese species? 2) How does Chinese pollination ecology compare with the development of pollination research abroad and which aspects of research should be pursued by Chinese anthecologists in the near future? 3) What research on pollination in China will advance our understanding and contribute to our ongoing analyses of endemism and conservation? Subsequently, we segregated and identified prospective lines of future research that are unique to China and can only be done in China. This requires discussing priorities within a systematic approach.
Article
Full-text available
The contribution of wild pollinators to food production has recently been assessed for many crops, although it remains unclear for several tropical crops. Granadilla (Passiflora ligularis Juss), a crop native to the tropical Andes, is one such crop where a gap exists regarding comprehensive knowledge about its pollination system. In a field experiment in the Colombian Andes, we 1) describe flower visitors in terms of visit quantity (visitation rate) and quality (touches of flower-reproductive structures), 2) assess the pollination system by comparing fruit set and fruit weight per flower in three pollination treatments: pollinator exclusion, open pollination, and supplementary pollination, and 3) evaluate pollination deficits (difference between open and supplementary pollination) in relation to pollinator density. We observed 12 bee species visiting granadilla flowers, with Apis mellifera Linnaeus being the most frequent species. However, large bees such as Xylocopa lachnea Moure and Epicharis rustica Olivier touched stigmata and anthers more often. Fruit set and fruit weight per flower were significantly lower in the pollinator exclusion treatment compared to open and supplementary pollination, while the latter treatments showed nonsignificant differences. Pollination deficit significantly decreased with the increasing density of large bees and wasps. Our results illustrate the high dependency of granadilla on wild pollinating insects and highlight the crucial role of large insects to granadilla production. This stresses the need to maintain or increase the density of large pollinators in granadilla production areas, which in turn will necessitate better knowledge on their ecological requirements to inform landscape planning and population-management programs.
Article
Full-text available
Agricultural intensification is one of the main causes for the current biodiversity crisis. While reversing habitat loss on agricultural land is challenging, increasing the farmland configurational heterogeneity (higher field border density) and farmland compositional heterogeneity (higher crop diversity) has been proposed to counteract some habitat loss. Here, we tested whether increased farmland configurational and compositional heterogeneity promote wild pollinators and plant reproduction in 229 landscapes located in four major western European agricultural regions. High-field border density consistently increased wild bee abundance and seed set of radish (Raphanus sativus), probably through enhanced connectivity. In particular, we demonstrate the importance of crop-crop borders for pollinator movement as an additional experiment showed higher transfer of a pollen analogue along crop-crop borders than across fields or along semi-natural crop borders. By contrast, high crop diversity reduced bee abundance, probably due to an increase of crop types with particularly intensive management. This highlights the importance of crop identity when higher crop diversity is promoted. Our results show that small-scale agricultural systems can boost pollinators and plant reproduction. Agri-environmental policies should therefore aim to halt and reverse the current trend of increasing field sizes and to reduce the amount of crop types with particularly intensive management.
Article
Full-text available
Global declines in insects have sparked wide interest among scientists, politicians, and the general public. Loss of insect diversity and abundance is expected to provoke cascading effects on food webs and to jeopardize ecosystem services. Our understanding of the extent and underlying causes of this decline is based on the abundance of single species or taxo-nomic groups only, rather than changes in insect biomass which is more relevant for ecological functioning. Here, we used a standardized protocol to measure total insect biomass using Malaise traps, deployed over 27 years in 63 nature protection areas in Germany (96 unique location-year combinations) to infer on the status and trend of local entomofauna. Our analysis estimates a seasonal decline of 76%, and midsummer decline of 82% in flying insect biomass over the 27 years of study. We show that this decline is apparent regardless of habitat type, while changes in weather, land use, and habitat characteristics cannot explain this overall decline. This yet unrecognized loss of insect biomass must be taken into account in evaluating declines in abundance of species depending on insects as a food source, and ecosystem functioning in the European landscape.
Article
Full-text available
Reports of world-wide decline of pollinators, and of bees in particular, raise increasing concerns about maintenance of pollination interactions. While local factors of bee decline are relatively well known and potential mitigation strategies at the landscape scale have been outlined, the regional and continental-scale threats to bee diversity have only been marginally explored. Here we document large-scale spatial patterns for a representative bee subfamily, the determinants of its species richness, and assess major threats to these pollinators. Using a comprehensive global dataset of Colletinae (genera Colletes, also called “polyester” or “cellophane” bees for their underground nests lined with a polyester secretion, and Mourecotelles), a species-rich subfamily whose organismal and physiological ecology is representative of many bees, we measured species richness and endemism on global to continental scales. We explored the relationships between bee species richness and potential environmental stress factors grouped into three categories: contemporary climate, habitat heterogeneity, and anthropogenic pressure. Bees of the subfamily Colletinae demonstrate the reversed latitudinal gradient in species richness and endemism suggested for bees; the highest species richness of Colletinae was found between 30° and 50° latitude in both the northern and southern hemispheres. Centres of endemism largely overlapped with those of species richness. The importance of the Greater Cape Floristic Region, previously identified as a centre of richness and endemism of bees, was confirmed for Colletinae. On the global scale, present-day climate was a significant predictor of species richness as was flowering plant diversity represented by vascular plant species richness and centres of plant diversity. Our main conclusion is that climate change constitutes a potential threat to bee diversity, as does declining diversity of vascular plants. However, a significant overlap between centres of bee richness and plant diversity might increase chances for developing conservation strategies.
Article
Full-text available
Approximately one-third of our food globally comes from insect-pollinated crops. The dependence on pollinators has been linked to yield instability, which could potentially become worse in a changing climate. Insect-pollinated crops produced via hybrid breeding (20% of fruit and vegetable production globally) are especially at risk as they are even more reliant on pollinators than open-pollinated plants. We already observe a wide range of fruit and seed yields between different cultivars of the same crop species, and it is unknown how existing variation will be affected in a changing climate. In this study, we examined how three hybrid carrot varieties with differential performance in the field responded to three temperature regimes (cooler than the historical average, average, and warmer that the historical average). We tested how temperature affected the plants' ability to set seed (seed set, pollen viability) as well as attract pollinators (nectar composition, floral volatiles). We found that there were significant intrinsic differences in nectar phenolics, pollen viability, and seed set between the carrot varieties, and that higher temperatures did not exaggerate those differences. However, elevated temperature did negatively affect several characteristics relating to the attraction and reward of pollinators (lower volatile production and higher nectar sugar concentration) across all varieties, which may decrease the attractiveness of this already pollinator-limited crop. Given existing predictions of lower pollinator populations in a warmer climate, reduced attractiveness would add yet another challenge to future food production.
Article
Full-text available
Pollination is indispensable for the reproduction of native and agricultural plant species. Current data underline the fragility of pollinator populations, mainly bees, which are threatened by increasing habitat fragmentation and use of agrochemicals. In this scenario, traditional communities in rural areas represent an important source of information, acquired upon direct observation of the biology and the ecology of animal species in these regions. The aim of this study was to evaluate the local environmental knowledge of students in elementary schools in rural areas about bees and pollination at two moments, before and after the use of specific educational activities. Initially 110 students were interviewed and they mentioned a relatively low number of ethnospecies. After the educational activities, we noticed a marked increase in this number, besides the significant learning of important concepts. Rural school communities lack information about pollination and insect pollinators and the insects, pollinators or not, still constitute animals of negative reputation for people. We believe that a deeper knowledge of pollination and pollinators may improve sustainable activities in the region.
Article
Over the past two decades, the cultivated area of oilseed rape (Brassica napus L. or OSR), a mass-flowering crop, has markedly increased in Europe in response to bioenergy demands. As well as representing a major shift in floral composition across the landscape, mass-flowering OSR may alter pollination services to other simultaneously blooming crops, either decreasing pollination via competition for pollinators or facilitating it via pollinator spill-over. Apple (Malus domestica Borkh.) is an economically important, obligately insect-pollinated fruit crop that co-flowers with OSR. Using twelve independent apple orchards varying in the percentage of OSR in the surrounding landscape, we investigated the effect of OSR on pollinators and pollination of co-blooming apple. We collected bees with pan traps and quantified flower visitors during transect walks in both crops and we experimentally measured pollination service provision to apple as fruit and seed set. We confirm that apples are highly dependent on animal pollination and report pollination limitation in our apple orchards. Honey bees were the numerically dominant visitors of apple flowers observed during transect walks. Though their numbers dropped with an increasing percentage of OSR in the landscape, the number of bumble bees visiting apple flowers remained stable and those of other wild bees rose. The pan trapped Shannon diversity of bees remained constant. We could not detect an effect of OSR in the landscape on apple fruit set or seed set, both of which remained stable. Local wild bee populations might compensate for the loss of honey bees in the provision of pollination services in apple, providing especially effective pollination. Our results underscore not only the dominant role of bees in apple pollination but also the importance of wild bee conservation for providing pollination insurance and stability of apple crop yields under changing agricultural policies and cropping practices.
Article
We investigated the fruit set and quality of yellow passion fruit subjected to hand and natural pollination by carpenter bees (Xylocopa spp.) in the Philippines. We also recorded the foraging behavior of the bees. A quadrat measuring 6 m x 7 m was marked in a yellow passion fruit plantation for the investigation. Two groups of 20 flowers that had been either hand pollinated or visited by the bees were followed to determine fruit set and quality. The hand pollinated flowers had significantly greater fruit set (15/20 versus 7/20), fruit weight, transverse diameter, longitudinal diameter, peel weight, number of seeds, and juice yield. Flowers that were self-pollinated by hand produced no fruit. Bee flower visit times and patterns were also investigated. The carpenter bees started visiting the passion fruit flowers from 7:00 AM to 5:00 PM, with peak visitation at 1:00 PM. The greatest mean duration of flower visits was observed at 11:00 AM (304 s), which coincided with the observed peak hour of flower opening. We observed random distances in the flight patterns of the carpenter bees, which was independent of flower distances (Kolmogorov-Smirnov test; µ=3.34 < σ²=7.91 vs. µ=2.40 > σ²=1.20). We conclude that passion fruit farmers can utilize supplemental hand pollination to increase yield when the main pollinators such as Xylocopa spp. are not available in sufficient numbers.
Article
Increasing demand for cocoa and climate-related yield declines have sparked a multi-stakeholder debate on cocoa production strategies. Agrochemical inputs and pollination enhancement through hand pollination are two strategies to increase yields. Here, we test both strategies with field experiments in Indonesia. We show that even partial hand pollination (13% of easily accessible flowers/tree), and not fertilizers or insecticides, increases yield/tree by 51%. The more laborious 100% hand pollination of the entire tree increases yield/tree by 161%, and farmer's annual net income from 994 USD/ha up to 1,677 USD/ha, or 69% in the study area, after accounting for farm operational, hand pollination labor, and opportunity costs. Thus, intensifying cocoa pollination appears to be a potential solution for closing cocoa yield gaps and should be considered in the current industry-led discussion of designing farms for mitigation of climate change.
Article
Pollination services to crops may be worsening because of declines in farmland pollinators, but the consequences for yields have been uncertain. We therefore investigated pollination limitation in four entomophilous crops (oilseed rape, sunflower, pears and pumpkin) by quantifying the difference in harvestable mass between open-pollinated and saturation-pollinated (hand-pollinated) flowers. We also examined whether pollination limitation in the four crops was associated with the number of flower visits by insects. Across 105 commercial fields in six European countries, the average decrease in harvestable mass due to pollination limitation was 2.8 % (SE = 1.15). Among crops, the highest decreases were in sunflowers (8%) and in one of three oilseed rape production regions (6%). We observed substantial variation among crops in the numbers of insect visits received by flowers, but it did not significantly correspond with the levels of pollination limitation. Our results suggest that yields in these crops were not severely pollination-limited in the regions studied and that other factors besides visitation by pollinators influenced the degree of pollination limitation.
Article
• The mutualistic interactions of plant‐pollinator networks provide myriad economic, ecological, and cultural constituents without which there would be severe environmental and societal consequences. Plant‐pollinator networks are becoming increasingly vulnerable to disturbance through intensifying anthropogenic land use and climate change. • Wild bees are central to pollination and documenting unique regional interactions between wild bees and floral hosts provides powerful insights into local ecology and biodiversity in addition to the potential to detect temporal network variation. • This study characterises the changes in a northern New England wild bee plant‐pollinator network over the past 125 years and reveals a striking increase in exotic bee and plant taxa over time. Here we document that declining wild bee species have historic ties to threatened and endangered plant species. These data provide a rare insight into the fragile nature of plant‐pollinator networks. • Notable specialist interactions between native taxa that were recorded in historical networks have been lost, most likely due to local extirpation of these now threatened and endangered plant species. Subsequent monitoring and conservation efforts focused on habitat restoration for declining wild bee and plant taxa are fundamental to the future preservation of regional native diversity.
Article
Wind is an important yet understudied environmental influence on foraging behaviour. We investigated the direct and indirect effects of wind on foraging worker honey bees, Apis mellifera. Bees were trained to an array of artificial flowers providing nectar rewards in a location sheltered from natural wind. To examine the direct effect, fans produced four different wind speeds between 0 and 3 m/s at three different flower spacings: 5 cm (flowers touching) and 10 cm and 20 cm (flowers not touching). To examine the indirect effect of wind moving flowers, flowers were moved 10 cm at three frequencies between 50 and 110 cycles/min at zero wind speed. We recorded the number of successful flower visits, time spent flying, search time on a flower and hesitancy to take off. Bees visited significantly fewer flowers with increasing wind speed which was caused by a significant increase in hesitancy to take off. This difference in flower visits between wind speeds was highest at the 20 cm spacing. Flower movement had no effect on foraging rate; however, there was a significant positive relationship between flower movement and the total time spent flying. This was counterbalanced by a significant reduction in time spent searching for the nectary after landing on a flower at the higher flower frequencies. Our results suggest that it is the direct effect of wind on hesitancy to take off that has the greatest effect on honey bee foraging rate.
Article
Insect pollination plays a vital role for the yield of many crops, such as apples, strawberries and coffee, which are economically significant commodities on the global market. Yet, knowledge about the role of insect pollination is lacking for many cash crops that support the livelihoods of small-scale farmers in developing countries. To assess if yields of watermelon are pollen limited, we conducted a supplemental hand-pollinated experiment (using a pollen mixture of cross and self-pollen) in 13 small-scale farms in an agricultural landscape in the Kilimanjaro and Arusha regions in northern Tanzania. We assessed fruit set, fruit abortion and weight of the mature fruits stemming from hand pollinated and control flowers. To check if differences in yield responses between hand-pollinated and control treatments depended on resource availability, we also accounted for local soil conditions. We found that hand pollination (i) increased the probability of fruit initiation by 30%, (ii) reduced the probability of fruit abortion by 13%, (iii) increased the probability of flowers developing into mature fruits by 42% and (iv) increased average fruit weight by 1.3 kg (±0.15 SE). Our results indicate that our system is pollen limited, due to insufficient visitor frequency and/or inefficient pollinator species. Fruit initiation and fruit weight were positively related to soil carbon, irrespective of treatment. The influence of soil moisture was not consistent across the measured responses, and differed between hand-pollinated and the control treatments. We suggest that farmers in our focal area should focus on improving the quality of the landscape to sustain and enhance healthy pollinator communities ultimately improving yields. We also suggest that farmers should continue current practices with respect to fertilization. The role of soil moisture on fruit initiation and maturation should be investigated to ensure that the positive effects of pollen is not hindered by soil moisture conditions.
Article
Urban areas are growing worldwide and alter landscapes in a persistent fashion, thereby affecting biodiversity and ecosystem services such as pollination in a little understood way. Here we present a systematic review of the peer-reviewed literature to identify the drivers of urban pollinator populations and pollination. A total of 141 studies were reviewed and qualitatively analyzed. Pollinator responses to urbanization were contrasting. We contend that positive responses were often associated with urban sprawl, i.e. moderate levels of urbanization of rural, mostly agricultural land below 50% impervious surface, whereas high levels of densification with high percentages of sealed and built-up area (above 50%), largely led to pollinator declines and loss of pollination services. Further, urbanization generally reduced pollinator diversity when compared to natural or semi-natural areas, but enhanced it when compared to intensified agricultural landscapes. In addition, pollinator responses were commonly highly trait-and scale-specic. Cavity nesters and generalist species usually profited more from urbanization than ground nesters and specialists. Overall, urban pollinator communities still seem to provide sufficient pollination services to wild vegetation and crops. Pollinator diversity generally increased with the amount of urban green spaces at the landscape scale, and locally with availability of nesting resources and flowering plants. Positive effects of floral additions were largely independent of the plant's origin, whether native or non-native. Only a few studies included landscape configuration. Likewise, abiotic urban drivers, e.g. heat island effects and air and light pollution, remain little studied. Tropical and developing regions, most heavily impacted by current and future urbanization, are strongly underrepresented. We conclude that biodiversity friendly urbanization can make a valuable contribution to pollinator conservation, in particular in face of the continued intensification of rural agriculture.
Article
Natural hazards are naturally occurring physical events that can impact human welfare both directly and indirectly, via shocks to ecosystems and the services they provide. Animal‐mediated pollination is critical for sustaining agricultural economies and biodiversity, yet stands to lose both from present exposure to natural hazards, and future climate‐driven shifts in their distribution, frequency, and intensity. In contrast to the depth of knowledge available for anthropogenic‐related threats, our understanding of how naturally occurring extreme events impact pollinators and pollination has not yet been synthesized. We performed a systematic review and meta‐analysis to examine the potential impacts of natural hazards on pollinators and pollination in natural and cultivated systems. From a total of 117 studies (74% of which were observational), we found evidence of community and population‐level impacts to plants and pollinators from seven hazard types, including climatological (extreme heat, fire, drought), hydrological (flooding), meteorological (hurricanes), and geophysical (volcanic activity, tsunamis). Plant and pollinator response depended on the type of natural hazard and level of biological organization observed; 19% of cases reported no significant impact, whereas the majority of hazards held consistent negative impacts. However, the effects of fire were mixed, but taxa specific; meta‐analysis revealed that bee abundance and species richness tended to increase in response to fire, differing significantly from the mainly negative response of Lepidoptera. Building from this synthesis, we highlight important future directions for pollination‐focused natural hazard research, including the need to: (a) advance climate change research beyond static “mean‐level” changes by better incorporating “shock” events; (b) identify impacts at higher levels of organization, including ecological networks and co‐evolutionary history; and (c) address the notable gap in crop pollination services research—particularly in developing regions of the world. We conclude by discussing implications for safeguarding pollination services in the face of global climate change.
Article
This paper estimates the economic value of ecosystem services provided by Brazilian native bee, Xylocopa spp. Latreille (Hymenoptera: Apidae), pollination on a scale relevant to individual smallholder farmers that produce yellow passion fruit (Passiflora edulis Sims). The study areas are located in the vicinity of Pedro de Toledo and Itariri (Sao Paulo State-Brazil), in the Atlantic Forest region. The local economy is based on family farms, small stores, and ecotourism. The value was obtained using the ecological economics Avoided Cost Method, also known as replacement cost. Farms from this region informally hire temporary day laborers to supplement natural pollination with manual pollination of passion fruit flowers, so the cost of contracting temporary laborers was used to estimate the economic value of bee pollination. The value of pollination services was estimated at US$ 2,583.00 per hectare over 2 yr of P. edulis farming. Our estimates based on passion fruit farmer surveys and ecological valuation over 2 yr suggest that manual pollination accounts for 44-48% of production costs and results in a loss of ~58% of profits when wild bee pollination services are not available and manual pollination is required. We suggest that smallholder farmers follow the suggestions of previous studies and conserve adequate forest habitat for bee nesting and foraging, plan pesticide use around flowering and pollination, and supplement bee populations to maximize the benefit of the pollination ecosystem service and profits.
Article
Background: Despite the call for the application of ergonomics in developing countries, the African share of ergonomic studies is modest. Date palm farming is considered one of the most important economic resources in hot and dry areas. In African countries, including Algeria, there exist millions of date palms. Date palm work can be precarious and associated with higher rates of work related musculoskeletal disorders. Objective: This paper aims to:1.Reveal how the workers climb the trunk of the date palm to get to the crown.2.Detect the amount of work related musculoskeletal disorders (WRMSDs) in date palm trees work, and how to combat it. Method: The descriptive method was used. Results: Objective 1, Majority of date palm workers are still using the traditional methods, i.e. free climbing, and belt aided climbing. However, a minority of workers have started using modern methods i.e. ladders, climbing devices, and modern technology (e.g. hydraulic lifts). Objective 2, the workers complained about WRMSDs presence in the shoulders, hands, wrists, lower back, hips knees, and feet. Efforts to combat these WRMSDs are personal, educational and scientific efforts. Conclusion: Regarding climbing, the traditional methods are still dominant, and the use of technology is very limited. As regards WRMSDs, date palm workers complain about their presence in many parts of the body.
Article
In this study, we investigated for the first time the concomitant effect of climate changes on a tropical crop, passion fruit (Passiflora edulis), and its two main pollinator bee species (Xylocopa frontalis and X. grisescens)in the Neotropics considering two of the IPCC environmental scenarios, RCP 4.5; RCP 8.5 (Representative Concentration Pathways), and in the years 2060 and 2080. We have shown that the climate changes may lead to changes in the natural ranges of Xylocopa bees, with considerable loss of habitable area for both bee species, as well as for cropping passion fruit for years 2060 and 2080, respectively. We also predicted a potential reduction over 50% in the overlapping of the remaining suitable areas for the bees and passion fruit, increasing the potential spatial mismatch between the crop and its pollinators. We conclude that the suitable areas to co-occurrence of passion fruit crop and its effective pollinators will be largely affected in the Neotropics and steps to mitigate the effects of the climate changes should be taken to ensure viable population of pollinators in the remaining suitable areas for both bees and the crop.
Technical Report
The SAVA Region in north-eastern Madagascar is the global centre of vanilla production. Here, around 70,000 farmers are estimated to produce 70-80% of all global bourbon vanilla. Yet, little is known about the farming population, their livelihoods, and the impact of vanilla cultivation on biodiversity. This publication presents the results of the Diversity Turn Baseline Survey (DTBS) that was conducted in 2017. The survey provides baseline data on the socio-economic characteristics and living conditions of the local population, and farming of vanilla as well as the most important other crops (n=1,800 households). As international demand for natural vanilla has increased considerably, special emphasis is placed on the vertical integration of vanilla farmers into the global vanilla value chain. This integration is increasingly accomplished through contract farming arrangements between vanilla farmers, collectors and exporters. After a first rise in vanilla prices in 2015, the current vanilla boom took off in 2016 and was still in full swing in 2017. Consequently, the start of the price boom coincides with this survey and its retrospective questions often address the situation in 2016. The large majority of the surveyed households (HHs) in the study region practice vanilla farming (83%). Of these, only 15% conclude formal contracts while the majority of farmers (63%) sell their vanilla in informal spot markets often depending on several middlemen. Our data show that the socio-economic situation of smallholder vanilla farmers has recently improved when considering vanilla prices received, education, access to electricity and ownership of assets. However, under the high vanilla prices, theft and crime are now key constraints for vanilla farmers. In addition to descriptive statistics, this publication compares selected data between male- and female-headed HHs, poor and non-poor HHs, and HHs with- and without contracts. Members of female-headed HHs have significantly lower education, lower labour availability, smaller fields and lower vanilla harvests than male-headed HHs. HHs with contracts possess more assets, are better educated, have higher labour availability, larger vanilla plots, and larger vanilla harvests than HHs without contracts. The DTBS confirms a number of benefits for smallholders who conclude contracts with vanilla exporters or collectors. Among these benefits are the significantly higher vanilla prices even during market peaks. However, the distribution of HHs with or without contracts is skewed indicating entry barriers for certain groups of smallholders. For example, female-headed HHs were significantly less likely to have a contract than male-headed HHs, and it appears that HHs with a contract had already been less poor than HHs without a contract prior to entering contract arrangements.
Article
There is growing demand for pollination services in agricultural production, which contrasts with declines of wild and managed pollinator populations. Macadamia (Macadamia integrifolia) is a mass-flowering crop that depends on pollination services and is increasingly cultivated in South Africa. We studied the crop's pollination in South African orchards considering variation in landscape context and the spatial arrangement of managed honeybees (Apis mellifera). We conducted pollination experiments and pollinator observations on macadamia trees along a distance gradient from orchard edges that bordered either near-natural or human-modified habitats. In addition, we mapped position and density of honeybee apiaries at orchard-level. Nut set of macadamia trees strongly relied on animal-mediated pollination: pollinator exclusion reduced the initial nut set (3 weeks after pollination) by 80% and the final nut set (15 weeks after pollination) by 54%. Supplemental hand-pollination of otherwise untreated flowers increased initial and final nut set by 66% and 44%, respectively, indicating substantial pollination limitation. The landscape context only weakly affected pollinator visitation to macadamia trees, with reduced visitation closer to orchard edges bordering human-modified habitats. Furthermore, we observed almost no wild pollinator species. Instead, honeybees constituted 99% of all visits, whereby honeybee visitation rates increased with a tree's connectivity to apiaries. However, neither initial nor final nut was related to visitation rates, and the final nut set was actually reduced where honeybee colony density was high, with a predicted 50% reduction in final nut set between the lowest and highest colony densities. Our study demonstrates a strong pollination limitation in South African macadamia orchards, where managed honeybees fail at delivering the increasing need for pollination services. Indeed, increasing their colony densities may further limit their pollination efficiency. A pollination management that also includes non-Apis managed pollinators and wild pollinators is possibly needed to increase nut set and provide solutions for increasing pollination service demands. In intensive macadamia orchards, this can also necessitate the need for more pollinator-friendly management practices, including habitat restoration and reduced pesticide application.
Article
The negative effects of climate change on cocoa production are often enhanced through agricultural intensification, while research institutions and enterprises try to minimize yield gaps with production strategies mitigating climate risk. Ecological intensification is such a production strategy, whereby yield increase is promoted through reduced agrochemical inputs and increased regulating ecosystem services such as pollination. However, we still know little about cocoa pollination ecology and services, although they appear to be key to understand yield functions. Here, we provide an extensive literature review on cocoa pollination focusing on three main aspects: non-plant (external) and plant regulated (internal) factors affecting pollination, pollinator agents, and ecological intensification management for enhancing pollination success and yield. Pollination services by many arthropod groups such as ants, bees, and parasitic wasps, and not only ceratopogonids, may be a way to increase cocoa productivity and secure smallholders income, but their role is unknown. Several environmental and socioeconomic factors can blur potential pollination benefits. Current knowledge gaps preclude our understanding of how to (i) identify the major pollinator species, (ii) disentangle the direct or indirect role of ants in pollination, (iii) design effective habitat improvements for pollination (by litter and shade management), and (iv) quantify the yield gaps due to pollination limitation. Optimizing cocoa pollination alone appears to be a powerful ecological tool to increase the yield of smallholders, but experimental research is required to validate these results in a realistic setting. In general, industry, governments and smallholders need to develop more joined efforts to ecological production strategies. In particular, farm-base management innovations based on robust scientific evidence must be designed to meet the increasing demand for chocolate and to mitigate cocoa yield gaps. This review suggests that diversified systems and associated ecosystem services, such as pollination, can help to achieve such goals.
Article
Intensification of agriculture and associated loss of habitat heterogeneity is a key driver of global declines in insect pollinators. Pollinators utilise different habitats to meet resource requirements throughout their life-span and it is widely accepted that their conservation requires a landscape-scale approach. Information on the mechanisms driving insect pollinators at the landscape scale is, however, lacking. To fill this knowledge gap, this novel study explores how pollinators utilise different habitats within a landscape and how utilisation changes over the season. Floral resources and insect pollinators (i.e. bumblebee, butterflies and hoverflies) were monitored during peak pollinator activity periods on a wide range of agricultural and semi-natural habitats in an intensive grassland landscape.
Article
Pollinating insects such as honeybees play a critical role in maintaining the natural environment. The decline in honeybee populations is a global issue with significant repercussions with respect to the pollination of plants. The simultaneous expression of multifunctionality from synthesized ionic liquid gels (ILGs) for biotechnology is presented in this study. We also demonstrate that, when mixed with photochromic organic compounds, ILGs display rapid color changes, similar to light-triggered camouflage, on living Musca domestica specimens. By further exploiting the physicochemical properties of ILGs, we were able to achieve effective pollen adsorption by ILG-functionalized Formica japonica specimens from Tulipa gesneriana flowers with high biocompatibility. In addition, a radiowave-controllable bio-inspired flying robot equipped with ILG-coated vertically aligned animal hairs could be used to successfully pollinate Lilium japonicum flowers. Such materially engineered artificial plant pollinators should lead to the development of high-performance robotics that can help counter the decline in honeybee populations.
Article
The effect of pollen supplementation in pistachio using different suspension media (Control: Open pollination, S: 10% sucrose, A: 0.1% Agar, Zn1: 0.01% zinc sulfate, Zn2: 0.02% zinc sulfate, P: 0.1% Pollen) were investigated in two orchards (A and B). Yield (fruit set and fruit drop) and fruit quality (percent split fruit, nut blank, abnormal fruit and kernel mineral content) were tested based on a block complete randomize design with three replications. The results indicated that kernel dry weight and kernel fresh weight were affected by pollination treatments so that treatments of SAZn1P (10% sucrose + 0.1% agar + 0.01% zinc sulfate + 1 g/L pollen), SAZn2P (10% sucrose + 0.1% agar + 0.02% zinc sulfate + 1 g/L pollen) and SA (10% sucrose + 0.1% agar) decreased kernel fresh weight compared to the control. The results also showed that SAZn1P treatment increased nut thickness and nut split percentage in orchard ‘B’. The highest final fruit set was obtained in orchard ‘A’ with SAZn2 treatment. According the results, when pollination is a limiting factor, supplementary pollination using enriched pollen suspension with Zn can improve yield and increase fruit quality.