Search

Fil: Senapathi, Deepa. University of Reading. School of Agriculture, Policy & Development. Centre for Agri-Environmental Research. Reino Unido. Fil: Fründ, Jochen. University of Freiburg. Faculty of Environment and Natural Resources. Biometry and Environmental System Analysis. Alemania. Fil: Albrecht, Matthias. Agroscope. Institute for Sustainability Sciences. Suiza. Fil: Garratt, Michael P. D. University of Reading. School of Agriculture, Policy & Development. Centre for Agri-Environmental Research. Reino Unido. Fil: Kleijn, David. Wageningen University. Plant Ecology and Nature Conservation Group. Países Bajos. Fil: Pickles, Brian J. University of Reading. School of Biological Sciences. Reino Unido. Fil: Potts, Simon G. University of Reading. School of Agriculture, Policy & Development. Centre for Agri-Environmental Research. Reino Unido. Fil: An, Jiandong. Chinese Academy of Agricultural Sciences. Institute of Apicultural Research. China. Fil: Andersson, Georg K. S. Universidad Nacional de Río Negro. Instituto de Investigaciones en Recursos Naturales, Agroecología y Desarrollo Rural. Río Negro, Argentina. Fil: Andersson, Georg K. S. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Recursos Naturales, Agroecología y Desarrollo Rural. Río Negro, Argentina. Fil: Bänsch, Svenja. University of Göttingen. Department of Crop Sciences. Functional Agrobiodiversity. Alemania. Fil: Basu, Parthiba. University of Calcutta. Centre for Pollination Studies. India. Fil: Benjamin, Faye. The State University of New Jersey. Department of Ecology, Evolution and Natural Resources. Estados Unidos. Fil: Bezerra, Antonio Diego M. The State University of New Jersey. Department of Ecology, Evolution and Natural Resources. Estados Unidos. Fil: Bhattacharya, Ritam. University of Calcutta. Centre for Pollination Studies. India. Fil: Biesmeijer Jacobus C. Naturalis Biodiversity Centre. Países Bajos. Fil: Blaauw, Brett. University of Georgia. Department of Entomology. Estados Unidos. Fil: Blitzer, Eleanor J. Carroll College. Department of Biology. Estados Unidos. Fil: Brittain, Claire A. Jealott’s Hill International Research Centre. Syngenta. Reino Unido. Fil: Carvalheiro, Luísa G. Universidade Federal de Goiás. Departamento de Ecologia. Brasil. Fil: Cariveau, Daniel P. University of Minnesota. Department of Entomology. Estados Unidos. Fil: Chakraborty, Pushan. University of Calcutta. Centre for Pollination Studies. India. Fil: Chatterjee, Arnob. University of Calcutta. Centre for Pollination Studies. India. Fil: Chatterjee, Soumik. University of Calcutta. Centre for Pollination Studies. India. Fil: Cusser, Sarah. Michigan State University. W. K. Kellogg Biological Station. Estados Unidos. Fil: Danforth, Bryan N. Cornell University. Department of Entomology. Estados Unidos. Fil: Degani, Erika. University of Reading. School of Agriculture, Policy & Development. Centre for Agri-Environmental Research. Reino Unido. Fil: Freitas, Breno M. The State University of New Jersey. Department of Ecology, Evolution and Natural Resources. Estados Unidos. Fil: Garibaldi, Lucas A. Universidad Nacional de Río Negro. Instituto de Investigaciones en Recursos Naturales, Agroecología y Desarrollo Rural. Río Negro, Argentina. Fil: Garibaldi, Lucas A. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Recursos Naturales, Agroecología y Desarrollo Rural. Río Negro, Argentina. Fil: Geslin, Benoit. Aix Marseille Univ, Avignon Université. IMBE. Francia. Fil: de Groot, G. Arjen. Wageningen University and Research. Wageningen Environmental Research. Países Bajos. Fil: Harrison, Tina. University of California Davis. Department of Entomology and Nematology. Estados Unidos. Fil: Howlett, Brad. The New Zealand Institute for Plant & Food Research Limited. Nueva Zelanda. Fil: Isaacs, Rufus. Michigan State University. Department of Entomology. Estados Unidos. Fil: Jha, Shalene. The University of Texas at Austin. Department of Integrative Biology. Estados Unidos. Fil: Klatt, Björn Kristian. University of Göttingen. Department of Crop Sciences. Agroecology. Alemania. Fil: Krewenka, Kristin. University of Heidelberg. Heidelberg Research Service. Alemania. Fil: Leigh, Samuel. University of Reading. School of Agriculture, Policy & Development. Centre for Agri-Environmental Research. Reino Unido. Fil: Lindström, Sandra A. M. Lund University. Department of Biology. Biodiversity. Suecia. Fil: Mandelik, Yael. The Hebrew University of Jerusalem. The Robert H. Smith Faculty of Agriculture, Food and Environment. Department of Entomology. Israel. Fil: McKerchar, Megan. University of Worcester. School of Science and Environment. Reino Unido. Fil: Park, Mia. Cornell University. Department of Entomology. Estados Unidos. Fil: Pisanty, Gideon. Canadian National Collection of Insects, Arachnids and Nematodes. Agriculture and Agri-Food Canada. Canada. Fil: Rader, Romina. University of New England. School of Environment and Rural Science. Australia. Fil: Reemer, Menno. Naturalis Biodiversity Centre. Países Bajos. Fil: Rundlöf, Maj. Lund University. Department of Biology. Biodiversity. Suecia. Fil: Smith, Barbara. University of Calcutta. Centre for Pollination Studies. India. Fil: Smith, Henrik G. Lund University. Centre of Environmental and Climate Research & Department of Biology. Suecia. Fil: Nunes Silva, Patrícia. Universidade do Vale do Rio dos Sinos. Programa de Pós-Graduação em Biologia. Brasil. Fil: Steffan-Dewenter, Ingolf. University of Würzburg. Department of Animal Ecology and Tropical Biology. Alemania. Fil: Tscharntke, Teja. University of Göttingen. Department of Crop Sciences. Agroecology. Alemania. Fil: Webber, Sean. University of Reading. School of Agriculture, Policy & Development. Centre for Agri-Environmental Research. Reino Unido. Fil: Westbury, Duncan B. University of Worcester. School of Science and Environment. Reino Unido. Fil: Westphal, Catrin. University of Göttingen. Department of Crop Sciences. Functional Agrobiodiversity. Alemania. Fil: Wickens, Jennifer B. University of Reading. School of Agriculture, Policy & Development. Centre for Agri-Environmental Research. Reino Unido. Fil: Wickens, Victoria J. University of Reading. School of Agriculture, Policy & Development. Centre for Agri-Environmental Research. Reino Unido. Fil: Winfree, Rachael. The State University of New Jersey. Department of Ecology, Evolution and Natural Resources. Estados Unidos. Fil: Zhang, Hong. Chinese Academy of Agricultural Sciences. Institute of Apicultural Research. China. Fil: Klein, Alexandra-Maria. University of Freiburg. Faculty of Environment and Natural Resources. Nature Conservation and Landscape Ecology. Alemania. While an increasing number of studies indicate that the range, diversity and abundance of many wild pollinators has declined, the global area of pollinator-dependent crops has significantly increased over the last few decades. Crop pollination studies to date have mainly focused on either identifying different guilds pollinating various crops, or on factors driving spatial changes and turnover observed in these communities. The mechanisms driving temporal stability for ecosystem functioning and services, however, remain poorly understood. Our study quantifies temporal variability observed in crop pollinators in 21 different crops across multiple years at a global scale. Using data from 43 studies from six continents, we show that (i) higher pollinator diversity confers greater inter-annual stability in pollinator communities, (ii) temporal variation observed in pollinator abundance is primarily driven by the three-most dominant species, and (iii) crops in tropical regions demonstrate higher inter-annual variability in pollinator species richness than crops in temperate regions. We highlight the importance of recognizing wild pollinator diversity in agricultural landscapes to stabilize pollinator persistence across years to protect both biodiversity and crop pollination services. Short-term agricultural management practices aimed at dominant species for stabilizing pollination services need to be considered alongside longer term conservation goals focussed on maintaining and facilitating biodiversity to confer ecological stability. .

There is compelling evidence that more diverse ecosystems deliver greater benefits to people, and these ecosystem services have become a key argument for biodiversity conservation. However, it is unclear how much biodiversity is needed to deliver ecosystem services in a cost-effective way. Here we show that, while the contribution of wild bees to crop production is significant, service delivery is restricted to a limited subset of all known bee species. Across crops, years and biogeographical regions, crop-visiting wild bee communities are dominated by a small number of common species, and threatened species are rarely observed on crops. Dominant crop pollinators persist under agricultural expansion and many are easily enhanced by simple conservation measures, suggesting that cost-effective management strategies to promote crop pollination should target a different set of species than management strategies to promote threatened bees. Conserving the biological diversity of bees therefore requires more than just ecosystem-service-based arguments.

Sustainable agricultural landscapes by definition provide high magnitude and stability of ecosystem services, biodiversity and crop productivity. However, few studies have considered landscape effects on the stability of ecosystem services. We tested whether isolation from florally diverse natural and semi-natural areas reduces the spatial and temporal stability of flower-visitor richness and pollination services in crop fields. We synthesised data from 29 studies with contrasting biomes, crop species and pollinator communities. Stability of flower-visitor richness, visitation rate (all insects except honey bees) and fruit set all decreased with distance from natural areas. At 1 km from adjacent natural areas, spatial stability decreased by 25, 16 and 9% for richness, visitation and fruit set, respectively, while temporal stability decreased by 39% for richness and 13% for visitation. Mean richness, visitation and fruit set also decreased with isolation, by 34, 27 and 16% at 1 km respectively. In contrast, honey bee visitation did not change with isolation and represented > 25% of crop visits in 21 studies. Therefore, wild pollinators are relevant for crop productivity and stability even when honey bees are abundant. Policies to preserve and restore natural areas in agricultural landscapes should enhance levels and reliability of pollination services.

Habitat loss and fragmentation in agricultural landscapes lead to severe declines of abundance and richness of many insect species in the remaining isolated semi-natural habitats. We analysed possible barrier effects of large hedges and corridor effects of narrow grass strips that were hypothesized to affect foraging and dispersal of hymenopterans. We selected calcareous grasslands in the vicinity of Gottingen (Germany), which harbour high Hymenoptera diversity and are starting points for foraging and dispersal in the landscape. We installed pan traps to sample bees (i) on the grasslands; (ii) on grassland edges behind adjacent hedges (potential barriers) and without hedges; (iii) on grass strips in 100 m distance to the grassland, which were connected or unconnected to the grassland; and (iv) unconnected (isolated) grass strips in 300 m and 750 m distance to test for corridor and isolation effects on abundance and species richness of foraging wild bees. Additionally we provided trap nests for bees, wasps and their parasitoids on the grasslands and the strips. Species abundance and richness declined with increasing isolation from grasslands for foraging solitary bees, trap-nesting bees, wasps and parasitoids, but not for foraging bumblebees. Hedges did not confine movement of foraging bees. We found no mitigating effects of (100 m) corridor strips on any of the observed groups. We conclude that conservation of semi-natural habitats as sources of bee and wasp diversity is important and that grass strips act as sinks rather than corridors when high quality patches are nearby.

© 2015 Macmillan Publishers Limited. All rights reserved. There is compelling evidence that more diverse ecosystems deliver greater benefits to people, and these ecosystem services have become a key argument for biodiversity conservation. However, it is unclear how much biodiversity is needed to deliver ecosystem services in a cost-effective way. Here we show that, while the contribution of wild bees to crop production is significant, service delivery is restricted to a limited subset of all known bee species. Across crops, years and biogeographical regions, crop-visiting wild bee communities are dominated by a small number of common species, and threatened species are rarely observed on crops. Dominant crop pollinators persist under agricultural expansion and many are easily enhanced by simple conservation measures, suggesting that cost-effective management strategies to promote crop pollination should target a different set of species than management strategies to promote threatened bees. Conserving the biological diversity of bees therefore requires more than just ecosystem-service-based arguments.

Background. Up to 75 % of crop species benefit at least to some degree from animal pollination for fruit or seed set and yield. However, basic information on the level of pollinator dependence and pollinator contribution to yield is lacking for many crops. Even less is known about how insect pollination affects crop quality. Given that habitat loss and agricultural intensification are known to decrease pollinator richness and abundance, there is a need to assess the consequences for different components of crop production. Methods. We used pollination exclusion on flowers or inflorescences on a whole plant basis to assess the contribution of insect pollination to crop yield and quality in four flowering crops (spring oilseed rape, field bean, strawberry, and buckwheat) located in four regions of Europe. For each crop, we recorded abundance and species richness of flower visiting insects in ten fields located along a gradient from simple to heterogeneous landscapes. Results. Insect pollination enhanced average crop yield between 18 and 71% depending on the crop. Yield quality was also enhanced in most crops. For instance, oilseed rape had higher oil and lower chlorophyll contents when adequately pollinated, the proportion of empty seeds decreased in buckwheat, and strawberries' commercial grade improved; however, we did not find higher nitrogen content in open pollinated field beans. Complex landscapes had a higher overall species richness of wild pollinators across crops, but visitation rates were only higher in complex landscapes for some crops. On the contrary, the overall yield was consistently enhanced by higher visitation rates, but not by higher pollinator richness. Discussion. For the four crops in this study, there is clear benefit delivered by pollinators on yield quantity and/or quality, but it is not maximized under current agricultural intensification. Honeybees, the most abundant pollinator, might partially compensate the loss of wild pollinators in some areas, but our results suggest the need of landscape-scale actions to enhance wild pollinator populations.

Bees provide essential pollination services that are potentially affected both by local farm management and the surrounding landscape. To better understand these different factors, we modelled the relative effects of landscape composition (nesting and floral resources within foraging distances), landscape configuration (patch shape, interpatch connectivity and habitat aggregation) and farm management (organic vs. conventional and local-scale field diversity), and their interactions, on wild bee abundance and richness for 39 crop systems globally. Bee abundance and richness were higher in diversified and organic fields and in landscapes comprising more high-quality habitats; bee richness on conventional fields with low diversity benefited most from high-quality surrounding land cover. Landscape configuration effects were weak. Bee responses varied slightly by biome. Our synthesis reveals that pollinator persistence will depend on both the maintenance of high-quality habitats around farms and on local management practices that may offset impacts of intensive monoculture agriculture. Bees provide essential pollination services that are potentially affected both by local farm management and the surrounding landscape. To better understand these different factors, we modelled the relative effects of landscape composition (nesting and floral resources within foraging distances), landscape configuration (patch shape, interpatch connectivity and habitat aggregation) and farm management (organic vs. conventional and local-scale field diversity), and their interactions, on wild bee abundance and richness for 39 cropsystems globally. Bee abundance and richness were higher in diversified and organic fields and in landscapes comprising more high-quality habitats; bee richness on conventional fields with low diversity benefited most from high-quality surrounding land cover. Landscape configuration effects were weak. Beeresponses varied slightly by biome. Our synthesis reveals that pollinator persistence will depend on boththe maintenance of high-quality habitats around farms and on local management practices that may offsetimpacts of intensive monoculture agriculture.

To better understand the dynamics of bee populations in crops, we assessed the effect of landscape context and habitat type on bee communities in annual entomophilous crops in Europe. We quantified bee communities in five pairs of crop-country: buckwheat in Poland, cantaloupe in France, field beans in the UK, spring oilseed rape in Sweden, and strawberries in Germany. For each country, 7–10 study fields were sampled over a gradient of increasing proportion of semi-natural habitats in the surrounding landscape. The CORINE land cover classification was used to characterize the landscape over a 3 km radius around each study field and we used multivariate and regression analyses to quantify the impact of landscape features on bee abundance and diversity at the sub-generic taxonomic level. Neither overall wild bee abundance nor diversity, taken as the number of sub-genera, was significantly affected by the proportion of semi-natural habitat. Therefore, we used the most precise level of the CORINE classification to examine the possible links between specific landscape features and wild bee communities. Bee community composition fell into three distinct groups across Europe: group 1 included Poland, Germany, and Sweden, group 2 the UK, and group 3 France. Among all three groups, wild bee abundance and sub-generic diversity were affected by 17 landscape elements including some semi-natural habitats (e.g., transitional woodland-shrub), some urban habitats (e.g., sport and leisure facilities) and some crop habitats (e.g., non-irrigated arable land). Some bee taxa were positively affected by urban habitats only, others by semi-natural habitats only, and others by a combination of semi-natural, urban and crop habitats. Bee sub-genera favoured by urban and crop habitats were more resistant to landscape change than those favoured only by semi-natural habitats. In agroecosystems, the agricultural intensification defined as the loss of semi-natural habitats does not necessarily cause a decline in evenness at the local level, but can change community composition towards a bee fauna dominated by common taxa.