@article{MoreauxMeirelesSonneetal.2022, author = {Moreaux, C{\´e}line and Meireles, Desir{\´e}e A. L. and Sonne, Jesper and Badano, Ernesto I. and Classen, Alice and Gonz{\´a}lez-Chaves, Adrian and Hip{\´o}lito, Juliana and Klein, Alexandra-Maria and Maruyama, Pietro K. and Metzger, Jean Paul and Philpott, Stacy M. and Rahbek, Carsten and Saturni, Fernanda T. and Sritongchuay, Tuanjit and Tscharntke, Teja and Uno, Shinsuke and Vergara, Carlos H. and Viana, Blandina F. and Strange, Niels and Dalsgaard, Bo}, title = {The value of biotic pollination and dense forest for fruit set of Arabica coffee: A global assessment}, series = {Agriculture, Ecosystems \& Environment}, volume = {323}, journal = {Agriculture, Ecosystems \& Environment}, doi = {10.1016/j.agee.2021.107680}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-370982}, year = {2022}, abstract = {Animal pollinators are globally threatened by anthropogenic land use change and agricultural intensification. The yield of many food crops is therefore negatively impacted because they benefit from biotic pollination. This is especially the case in the tropics. For instance, fruit set of Coffea arabica has been shown to increase by 10-30\% in plantations with a high richness of bee species, possibly influenced by the availability of surrounding forest habitat. Here, we performed a global literature review to (1) assess how much animal pollination enhances coffee fruit set, and to (2) examine the importance of the amount of forest cover, distance to nearby forest and forest canopy density for bee species richness and coffee fruit set. Using a systematic literature review, we identified eleven case studies with a total of 182 samples where fruit set of C. arabica was assessed. We subsequently gathered forest data for all study sites from satellite imagery. We modelled the effects of open (all forest with a canopy density of ≥25\%), closed (≥50\%) and dense (≥75\%) forests on pollinator richness and fruit set of coffee. Overall, we found that animal pollination increases coffee fruit set by ~18\% on average. In only one of the case studies, regression results indicate a positive effect of dense forest on coffee fruit set, which increased with higher forest cover and shorter distance to the forest. Against expectations, forest cover and distance to open forest were not related to bee species richness and fruit set. In summary, we provide strong empirical support for the notion that animal pollinators increase coffee fruit set. Forest proximity had little overall influence on bee richness and coffee fruit set, except when farms were surrounded by dense tropical forests, potentially because these may provide high-quality habitats for bees pollinating coffee. We, therefore, advocate that more research is done to understand the biodiversity value of dense forest for pollinators, notably assessing the mechanisms underlying the importance of forest for pollinators and their pollination services.}, language = {en} } @article{MaasBrandlHussainetal.2021, author = {Maas, Bea and Brandl, Manuela and Hussain, Raja Imran and Frank, Thomas and Zulka, Klaus Peter and Rabl, Dominik and Walcher, Ronnie and Moser, Dietmar}, title = {Functional traits driving pollinator and predator responses to newly established grassland strips in agricultural landscapes}, series = {Journal of Applied Ecology}, volume = {58}, journal = {Journal of Applied Ecology}, doi = {10.1111/1365-2664.13892}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-369992}, pages = {1728-1737}, year = {2021}, abstract = {Agricultural biodiversity and associated ecosystem functions are declining at alarming rates due to widespread land use intensification. They can only be maintained through targeted landscape management that supports species with different habitat preferences, dispersal capacities and other functional traits that determine their survival. However, we need better understanding whether short-term measures can already improve functional diversity in European agroecosystems. We investigated spatio-temporal responses of bees (solitary bees, bumblebees and honey bees), hoverflies, carabid beetles and spiders to newly established grassland strips in Lower Austria over 3 years, and along a distance gradient to old grasslands. Specifically, we asked if new grasslands, compared to old grasslands and cereal fields, serve as temporal dispersal habitat or corridor, and how species-specific traits affect dispersal patterns. Using a trait-based functional diversity approach, we investigated year and distance effects for nine selected key traits per taxon (e.g. body size, feeding guild and habitat preferences). Our results show that the functional diversity of predators and pollinators (i.e. functional richness and evenness), as well as community-weighted means of selected key traits in new grasslands significantly differed from adjacent cereal fields, but only slowly adjusted to adjacent old grasslands. These effects significantly decreased with increasing distance to old grasslands for carabids and spiders, but not for mobile bees and hoverflies. Synthesis and applications. Over 3 years, newly established grassland strips supported larger sized and actively foraging/hunting species in the agricultural landscape. Adjacent crops likely benefit from such measures through enhanced functional diversity and related ecosystem services. However, our results also suggest that 3-year period is too short to enhance the occurrence of pollinators and epigeic predators in new grasslands. Agri-environment measures need to be complemented by the conservation of permanent habitats to effectively maintain species and functional diversity. Our findings should be acknowledged by European policy and agricultural decision makers for the design of more effective agri-environment schemes, taking into account trait-dependent species responses to land use change.}, language = {en} } @article{KendallRaderGagicetal.2019, author = {Kendall, Liam K. and Rader, Romina and Gagic, Vesna and Cariveau, Daniel P. and Albrecht, Matthias and Baldock, Katherine C. R. and Freitas, Breno M. and Hall, Mark and Holzschuh, Andrea and Molina, Francisco P. and Morten, Joanne M. and Pereira, Janaely S. and Portman, Zachary M. and Roberts, Stuart P. M. and Rodriguez, Juanita and Russo, Laura and Sutter, Louis and Vereecken, Nicolas J. and Bartomeus, Ignasi}, title = {Pollinator size and its consequences: Robust estimates of body size in pollinating insects}, series = {Ecology and Evolution}, volume = {9}, journal = {Ecology and Evolution}, doi = {10.1002/ece3.4835}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-325705}, pages = {1702-1714}, year = {2019}, abstract = {Body size is an integral functional trait that underlies pollination-related ecological processes, yet it is often impractical to measure directly. Allometric scaling laws have been used to overcome this problem. However, most existing models rely upon small sample sizes, geographically restricted sampling and have limited applicability for non-bee taxa. Allometric models that consider biogeography, phylogenetic relatedness, and intraspecific variation are urgently required to ensure greater accuracy. We measured body size as dry weight and intertegular distance (ITD) of 391 bee species (4,035 specimens) and 103 hoverfly species (399 specimens) across four biogeographic regions: Australia, Europe, North America, and South America. We updated existing models within a Bayesian mixed-model framework to test the power of ITD to predict interspecific variation in pollinator dry weight in interaction with different co-variates: phylogeny or taxonomy, sexual dimorphism, and biogeographic region. In addition, we used ordinary least squares regression to assess intraspecific dry weight ~ ITD relationships for ten bees and five hoverfly species. Including co-variates led to more robust interspecific body size predictions for both bees and hoverflies relative to models with the ITD alone. In contrast, at the intraspecific level, our results demonstrate that the ITD is an inconsistent predictor of body size for bees and hoverflies. The use of allometric scaling laws to estimate body size is more suitable for interspecific comparative analyses than assessing intraspecific variation. Collectively, these models form the basis of the dynamic R package, "pollimetry," which provides a comprehensive resource for allometric pollination research worldwide.}, language = {en} } @article{HornickRichterHarpoleetal.2022, author = {Hornick, Thomas and Richter, Anett and Harpole, William Stanley and Bastl, Maximilian and Bohlmann, Stephanie and Bonn, Aletta and Bumberger, Jan and Dietrich, Peter and Gemeinholzer, Birgit and Grote, R{\"u}diger and Heinold, Bernd and Keller, Alexander and Luttkus, Marie L. and M{\"a}der, Patrick and Motivans Švara, Elena and Passonneau, Sarah and Punyasena, Surangi W. and Rakosy, Demetra and Richter, Ronny and Sickel, Wiebke and Steffan-Dewenter, Ingolf and Theodorou, Panagiotis and Treudler, Regina and Werchan, Barbora and Werchan, Matthias and Wolke, Ralf and Dunker, Susanne}, title = {An integrative environmental pollen diversity assessment and its importance for the Sustainable Development Goals}, series = {Plants, People, Planet}, volume = {4}, journal = {Plants, People, Planet}, number = {2}, doi = {10.1002/ppp3.10234}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-276487}, pages = {110 -- 121}, year = {2022}, abstract = {Societal Impact Statement Pollen relates to many aspects of human and environmental health, which protection and improvement are endorsed by the United Nations Sustainable Development Goals. By highlighting these connections in the frame of current challenges in monitoring and research, we discuss the need of more integrative and multidisciplinary pollen research related to societal needs, improving health of humans and our ecosystems for a sustainable future. Summary Pollen is at once intimately part of the reproductive cycle of seed plants and simultaneously highly relevant for the environment (pollinators, vector for nutrients, or organisms), people (food safety and health), and climate (cloud condensation nuclei and climate reconstruction). We provide an interdisciplinary perspective on the many and connected roles of pollen to foster a better integration of the currently disparate fields of pollen research, which would benefit from the sharing of general knowledge, technical advancements, or data processing solutions. We propose a more interdisciplinary and holistic research approach that encompasses total environmental pollen diversity (ePD) (wind and animal and occasionally water distributed pollen) at multiple levels of diversity (genotypic, phenotypic, physiological, chemical, and functional) across space and time. This interdisciplinary approach holds the potential to contribute to pressing human issues, including addressing United Nations Sustainable Development Goals, fostering social and political awareness of these tiny yet important and fascinating particles.}, language = {en} } @article{SchenkKraussHolzschuh2018, author = {Schenk, Mariela and Krauss, Jochen and Holzschuh, Andrea}, title = {Desynchronizations in bee-plant interactions cause severe fitness losses in solitary bees}, series = {Journal of Animal Ecology}, volume = {87}, journal = {Journal of Animal Ecology}, number = {1}, doi = {10.1111/1365-2656.12694}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-228533}, pages = {139-149}, year = {2018}, abstract = {1. Global warming can disrupt mutualistic interactions between solitary bees and plants when increasing temperature differentially changes the timing of interacting partners. One possible scenario is for insect phenology to advance more rapidly than plant phenology. 2. However, empirical evidence for fitness consequences due to temporal mismatches is lacking for pollinators and it remains unknown if bees have developed strategies to mitigate fitness losses following temporal mismatches. 3. We tested the effect of temporal mismatches on the fitness of three spring-emerging solitary bee species, including one pollen specialist. Using flight cages, we simulated (i) a perfect synchronization (from a bee perspective): bees and flowers occur simultaneously, (ii) a mismatch of 3days and (iii) a mismatch of 6days, with bees occurring earlier than flowers in the latter two cases. 4. A mismatch of 6days caused severe fitness losses in all three bee species, as few bees survived without flowers. Females showed strongly reduced activity and reproductive output compared to synchronized bees. Fitness consequences of a 3-day mismatch were species-specific. Both the early-spring species Osmia cornuta and the mid-spring species Osmia bicornis produced the same number of brood cells after a mismatch of 3days as under perfect synchronization. However, O.cornuta decreased the number of female offspring, whereas O.bicornis spread the brood cells over fewer nests, which may increase offspring mortality, e.g. due to parasitoids. The late-spring specialist Osmia brevicornis produced fewer brood cells even after a mismatch of 3days. Additionally, our results suggest that fitness losses after temporal mismatches are higher during warm than cold springs, as the naturally occurring temperature variability revealed that warm temperatures during starvation decreased the survival rate of O.bicornis. 5. We conclude that short temporal mismatches can cause clear fitness losses in solitary bees. Although our results suggest that bees have evolved species-specific strategies to mitigate fitness losses after temporal mismatches, the bees were not able to completely compensate for impacts on their fitness after temporal mismatches with their food resources.}, subject = {pollination}, language = {en} } @article{ClassenEardleyHempetal.2020, author = {Classen, Alice and Eardley, Connal D. and Hemp, Andreas and Peters, Marcell K. and Peters, Ralph S. and Ssymank, Axel and Steffan-Dewenter, Ingolf}, title = {Specialization of plant-pollinator interactions increases with temperature at Mt. Kilimanjaro}, series = {Ecology and Evolution}, volume = {10}, journal = {Ecology and Evolution}, number = {4}, doi = {10.1002/ece3.6056}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-235959}, pages = {2182-2195}, year = {2020}, abstract = {Aim: Species differ in their degree of specialization when interacting with other species, with significant consequences for the function and robustness of ecosystems. In order to better estimate such consequences, we need to improve our understanding of the spatial patterns and drivers of specialization in interaction networks. Methods: Here, we used the extensive environmental gradient of Mt. Kilimanjaro (Tanzania, East Africa) to study patterns and drivers of specialization, and robustness of plant-pollinator interactions against simulated species extinction with standardized sampling methods. We studied specialization, network robustness and other network indices of 67 quantitative plant-pollinator networks consisting of 268 observational hours and 4,380 plant-pollinator interactions along a 3.4 km elevational gradient. Using path analysis, we tested whether resource availability, pollinator richness, visitation rates, temperature, and/or area explain average specialization in pollinator communities. We further linked pollinator specialization to different pollinator taxa, and species traits, that is, proboscis length, body size, and species elevational ranges. Results: We found that specialization decreased with increasing elevation at different levels of biological organization. Among all variables, mean annual temperature was the best predictor of average specialization in pollinator communities. Specialization differed between pollinator taxa, but was not related to pollinator traits. Network robustness against simulated species extinctions of both plants and pollinators was lowest in the most specialized interaction networks, that is, in the lowlands. Conclusions: Our study uncovers patterns in plant-pollinator specialization along elevational gradients. Mean annual temperature was closely linked to pollinator specialization. Energetic constraints, caused by short activity timeframes in cold highlands, may force ectothermic species to broaden their dietary spectrum. Alternatively or in addition, accelerated evolutionary rates might facilitate the establishment of specialization under warm climates. Despite the mechanisms behind the patterns have yet to be fully resolved, our data suggest that temperature shifts in the course of climate change may destabilize pollination networks by affecting network architecture.}, language = {en} } @article{StreinzerChakravortyNeumayeretal.2019, author = {Streinzer, Martin and Chakravorty, Jharna and Neumayer, Johann and Megu, Karsing and Narah, Jaya and Schmitt, Thomas and Bharti, Himender and Spaethe, Johannes and Brockmann, Axel}, title = {Species composition and elevational distribution of bumble bees (Hymenoptera, Apidae, Bombus Latreille) in the East Himalaya, Arunachal Pradesh, India}, series = {ZooKeys}, volume = {851}, journal = {ZooKeys}, doi = {10.3897/zookeys.851.32956}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-201937}, pages = {71-89}, year = {2019}, abstract = {The East Himalaya is one of the world's most biodiverse ecosystems. However, very little is known about the abundance and distribution of many plant and animal taxa in this region. Bumble bees are a group of cold-adapted and high elevation insects that fulfil an important ecological and economical function as pollinators of wild and agricultural flowering plants and crops. The Himalayan mountain range provides ample suitable habitats for bumble bees. Systematic study of Himalayan bumble bees began a few decades ago and the main focus has centred on the western region, while the eastern part of the mountain range has received little attention and only a few species have been verified. During a three-year survey, more than 700 bumble bee specimens of 21 species were collected in Arunachal Pradesh, the largest of the north-eastern states of India. The material included a range of species that were previously known from a limited number of collected specimens, which highlights the unique character of the East Himalayan ecosystem. Our results are an important first step towards a future assessment of species distribution, threat, and conservation. Clear elevation patterns of species diversity were observed, which raise important questions about the functional adaptations that allow bumble bees to thrive in this particularly moist region in the East Himalaya.}, language = {en} } @article{SteinCoulibalyStenchlyetal.2017, author = {Stein, Katharina and Coulibaly, Drissa and Stenchly, Kathrin and Goetze, Dethardt and Porembski, Stefan and Lindner, Andr{\´e} and Konat{\´e}, Souleymane and Linsenmair, Eduard K.}, title = {Bee pollination increases yield quantity and quality of cash crops in Burkina Faso, West Africa}, series = {Scientific Reports}, volume = {7}, journal = {Scientific Reports}, number = {17691}, doi = {10.1038/s41598-017-17970-2}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-169914}, year = {2017}, abstract = {Mutualistic biotic interactions as among flowering plants and their animal pollinators are a key component of biodiversity. Pollination, especially by insects, is a key element in ecosystem functioning, and hence constitutes an ecosystem service of global importance. Not only sexual reproduction of plants is ensured, but also yields are stabilized and genetic variability of crops is maintained, counteracting inbreeding depression and facilitating system resilience. While experiencing rapid environmental change, there is an increased demand for food and income security, especially in sub-Saharan communities, which are highly dependent on small scale agriculture. By combining exclusion experiments, pollinator surveys and field manipulations, this study for the first time quantifies the contribution of bee pollinators to smallholders' production of the major cash crops, cotton and sesame, in Burkina Faso. Pollination by honeybees and wild bees significantly increased yield quantity and quality on average up to 62\%, while exclusion of pollinators caused an average yield gap of 37\% in cotton and 59\% in sesame. Self-pollination revealed inbreeding depression effects on fruit set and low germination rates in the F1-generation. Our results highlight potential negative consequences of any pollinator decline, provoking risks to agriculture and compromising crop yields in sub-Saharan West Africa.}, language = {en} } @article{StejskalStreinzerDyeretal.2015, author = {Stejskal, Kerstin and Streinzer, Martin and Dyer, Adrian and Paulus, Hannes F. and Spaethe, Johannes}, title = {Functional Significance of Labellum Pattern Variation in a Sexually Deceptive Orchid (Ophrys heldreichii): Evidence of Individual Signature Learning Effects}, series = {PLoS One}, volume = {10}, journal = {PLoS One}, number = {11}, doi = {10.1371/journal.pone.0142971}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-137582}, pages = {e0142971}, year = {2015}, abstract = {Mimicking female insects to attract male pollinators is an important strategy in sexually deceptive orchids of the genus Ophrys, and some species possess flowers with conspicuous labellum patterns. The function of the variation of the patterns remains unresolved, with suggestions that these enhance pollinator communication. We investigated the possible function of the labellum pattern in Ophrys heldreichii, an orchid species in which the conspicuous and complex labellum pattern contrasts with a dark background. The orchid is pollinated exclusively by males of the solitary bee, Eucera berlandi. Comparisons of labellum patterns revealed that patterns within inflorescences are more similar than those of other conspecific plants. Field observations showed that the males approach at a great speed and directly land on flowers, but after an unsuccessful copulation attempt, bees hover close and visually scan the labellum pattern for up to a minute. Learning experiments conducted with honeybees as an accessible model of bee vision demonstrated that labellum patterns of different plants can be reliably learnt; in contrast, patterns of flowers from the same inflorescence could not be discriminated. These results support the hypothesis that variable labellum patterns in O. heldreichii are involved in flower-pollinator communication which would likely help these plants to avoid geitonogamy.}, language = {en} } @article{RakosyStreinzerPaulusetal.2012, author = {Rakosy, Demetra and Streinzer, Martin and Paulus, Hannes F. and Spaethe, Johannes}, title = {Floral visual signal increases reproductive success in a sexually deceptive orchid}, series = {Arthropod-Plant Interactions}, volume = {6}, journal = {Arthropod-Plant Interactions}, number = {4}, doi = {10.1007/s11829-012-9217-0}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-127209}, pages = {671-681}, year = {2012}, abstract = {Sexually deceptive orchids mimic signals emitted by female insects in order to attract mate-searching males. Specific attraction of the targeted pollinator is achieved by sex pheromone mimicry, which constitutes the major attraction channel. In close vicinity of the flower, visual signals may enhance attraction, as was shown recently in the sexually deceptive orchid Ophrys heldreichii. Here, we conducted an in situ manipulation experiment in two populations of O. heldreichii on Crete to investigate whether the presence/absence of the conspicuous pink perianth affects reproductive success in two natural orchid populations. We estimated reproductive success of three treatment groups (with intact, removed and artificial perianth) throughout the flowering period as pollinaria removal (male reproductive success) and massulae deposition (female reproductive success). Reproductive success was significantly increased by the presence of a strong visual signal—the conspicuous perianth—in one study population, however, not in the second, most likely due to the low pollinator abundance in the latter population. This study provides further evidence that the coloured perianth in O. heldreichii is adaptive and thus adds to the olfactory signal to maximise pollinator attraction and reproductive success.}, language = {en} }