scholarly journals A heterogeneous landscape does not guarantee high crop pollination

2016 ◽  
Vol 283 (1838) ◽  
pp. 20161472 ◽  
Author(s):  
Ulrika Samnegård ◽  
Peter A. Hambäck ◽  
Debissa Lemessa ◽  
Sileshi Nemomissa ◽  
Kristoffer Hylander
Keyword(s):  
Forest Cover ◽  
Agricultural Landscape ◽  
Pollen Limitation ◽  
Crop Pollination ◽  
Pollination Services ◽  
Manipulative Experiment ◽  
Agricultural Matrix ◽  
Heterogeneous Landscape ◽  
Yield Gaps ◽  
Bee Abundance

The expansion of pollinator-dependent crops, especially in the developing world, together with reports of worldwide pollinator declines, raises concern of possible yield gaps. Farmers directly reliant on pollination services for food supply often live in regions where our knowledge of pollination services is poor. In a manipulative experiment replicated at 23 sites across an Ethiopian agricultural landscape, we found poor pollination services and severe pollen limitation in a common oil crop. With supplementary pollination, the yield increased on average by 91%. Despite the heterogeneous agricultural matrix, we found a low bee abundance, which may explain poor pollination services. The variation in pollen limitation was unrelated to surrounding forest cover, local bee richness and bee abundance. While practices that commonly increase pollinators (restricted pesticide use, flower strips) are an integral part of the landscape, these elements are apparently insufficient. Management to increase pollination services is therefore in need of urgent investigation.

scholarly journals Honey bee hives decrease wild bee abundance, species richness, and fruit count on farms regardless of wildflower strips

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
G. M. Angelella ◽  
C. T. McCullough ◽  
M. E. O’Rourke
Keyword(s):  
Species Richness ◽  
Honey Bee ◽  
Crop Pollination ◽  
Pollination Services ◽  
Wild Bee ◽  
Wildflower Strips ◽  
Negative Impacts ◽  
Bee Communities ◽  
Winter Squash ◽  
Bee Abundance

AbstractPollinator refuges such as wildflower strips are planted on farms with the goals of mitigating wild pollinator declines and promoting crop pollination services. It is unclear, however, whether or how these goals are impacted by managed honey bee (Apis mellifera L.) hives on farms. We examined how wildflower strips and honey bee hives and/or their interaction influence wild bee communities and the fruit count of two pollinator-dependent crops across 21 farms in the Mid-Atlantic U.S. Although wild bee species richness increased with bloom density within wildflower strips, populations did not differ significantly between farms with and without them whereas fruit counts in both crops increased on farms with wildflower strips during one of 2 years. By contrast, wild bee abundance decreased by 48%, species richness by 20%, and strawberry fruit count by 18% across all farm with honey bee hives regardless of wildflower strip presence, and winter squash fruit count was consistently lower on farms with wildflower strips with hives as well. This work demonstrates that honey bee hives could detrimentally affect fruit count and wild bee populations on farms, and that benefits conferred by wildflower strips might not offset these negative impacts. Keeping honey bee hives on farms with wildflower strips could reduce conservation and pollination services.

scholarly journals Environmental determinants of haemosporidian parasite prevalence in a declining population of Tree swallows

Parasitology ◽  
2017 ◽  
Vol 145 (7) ◽  
pp. 961-970 ◽  
Author(s):  
Audrey Turcotte ◽  
Marc Bélisle ◽  
Fanie Pelletier ◽  
Dany Garant
Keyword(s):  
Forest Cover ◽  
Agricultural Landscape ◽  
Parasite Prevalence ◽  
Landscape Composition ◽  
Breeding Period ◽  
Tree Swallows ◽  
Environmental Determinants ◽  
Negative Effects ◽  
Haemosporidian Parasite ◽  
Haemosporidian Parasites

AbstractThe prevalence of vector-borne parasites such as haemosporidian species is influenced by several environmental factors. While the negative effects of parasitism on hosts are well documented, these can also be amplified by interactions with environmental stressors, many of which are anthropogenic. Yet, we know little about the possible effects of anthropogenic perturbations on parasite prevalence. The goals of this study were to assess the prevalence and environmental determinants of haemosporidian parasites in a declining population of Tree swallows (Tachycineta bicolor) living in an agricultural landscape in southern Québec, Canada. Overall, a low prevalence and a moderate lineage diversity were identified in both adults and nestlings, confirming that transmission can occur during the breeding period. Anthropic areas, extensive cultures (hayfields and pastures) and forest cover within 500 km of nest boxes, as well as daily temperature fluctuations, were all related to infection by haemosporidian parasites. These findings suggest that anthropogenic alterations of landscape composition can modulate the prevalence of haemosporidian parasites in Tree swallows. Our results represent a baseline for future comparative studies assessing haemosporidian parasite prevalence in human-modified landscapes.

Pollen limitation and xenia effects in a cultivated mass-flowering tree, Macadamia integrifolia (Proteaceae)

2021 ◽  
Author(s):  
Stephen J Trueman ◽  
Wiebke Kämper ◽  
Joel Nichols ◽  
Steven M Ogbourne ◽  
David Hawkes ◽  
...  
Keyword(s):  
Food Production ◽  
Fruit Set ◽  
Pollen Limitation ◽  
Pollination Services ◽  
Mass Flowering ◽  
Shell Mass ◽  
Cross Pollination ◽  
Macadamia Integrifolia ◽  
Kernel Yield ◽  
Flowering Tree

Abstract Background and Aims Pollen limitation is most prevalent among bee-pollinated plants, self-incompatible plants, and tropical plants. However, we have very little understanding of the extent to which pollen limitation affects fruit set in mass-flowering trees despite tree crops accounting for at least 600 million tons of the 9,200 million tons of annual global food production. Methods We determined the extent of pollen limitation in a bee-pollinated, partially self-incompatible, subtropical tree by hand cross-pollinating the majority of flowers on mass-flowering macadamia (Macadamia integrifolia) trees that produce about 200,000–400,000 flowers. We measured tree yield and kernel quality and estimated final fruit set. We genotyped individual kernels by MassARRAY to determine levels of outcrossing in orchards and assess paternity effects on nut quality. Key Results Macadamia trees were pollen limited. Supplementary cross-pollination increased nut-in-shell yield, kernel yield and fruit set by as much as 97%, 109% and 92%, respectively. The extent of pollen limitation depended upon the proximity of experimental trees to trees of another cultivar because macadamia trees were highly outcrossing. Between 84% and 100% of fruit arose from cross-pollination, even at 200 m (25 rows) from orchard blocks of another cultivar. Large variations in nut-in-shell mass, kernel mass, kernel recovery and kernel oil concentration were related to differences in fruit paternity, including between self-pollinated and cross-pollinated fruit, thus demonstrating pollen-parent effects on fruit quality, i.e. xenia. Conclusions This study is the first to demonstrate pollen limitation in a mass-flowering tree. Improved pollination led to increased kernel yield of 0.31–0.59 tons per hectare, which equates currently to higher farm-gate income of approximately US3,720–US7,080 per hectare. The heavy reliance of macadamia flowers on cross-pollination and the strong xenia effects on kernel mass demonstrate the high value that pollination services can provide to food production.

scholarly journals Landscape effects on crop pollination services: are there general patterns?

2008 ◽  
Vol 11 (5) ◽  
pp. 499-515 ◽  
Author(s):  
Taylor H. Ricketts ◽  
James Regetz ◽  
Ingolf Steffan-Dewenter ◽  
Saul A. Cunningham ◽  
Claire Kremen ◽  
...  
Keyword(s):  
Crop Pollination ◽  
Pollination Services ◽  
Landscape Effects

scholarly journals Methods of Landscape Valorization and Possibilities of Its Application in Hunting Area Categorisation

2020 ◽  
Author(s):  
Szewczyk Grzegorz ◽  
Krzysztof Lipka ◽  
Piotr Wężyk ◽  
Karolina Zięba-Kulawik ◽  
Monika Winczek
Keyword(s):  
Natural Environment ◽  
Functional Role ◽  
Large Scale ◽  
Forest Cover ◽  
Agricultural Landscape ◽  
Environmental Changes ◽  
Environmental Values ◽  
Small Game ◽  
Forest Habitats

As a result of environmental changes, assessment indexes for the agricultural landscape have been changing dramatically. Being at the interface of human activity and the natural environment, hunting is particularly sensitive to environmental changes, such as increasing deforestation or large-scale farming. The classical categorisation of hunting grounds takes into account the area, forest cover, number of forest complexes, fertility of forest habitats, lack of continuity of areas potentially favourable to wild animals. Landscape assessment methods used in architecture often better reflect the actual breeding and hunting value of a given area, especially in relation to fields and forests. The forest-field mosaic, large spatial fragmentation as well as interweaving of natural environment elements with buildings do not have to be the factors that limit the numbers of small game. Identification of the constituents of architectural-landscape interiors: content and significance assessment, determination of the functional role or assessment based on the general environmental values being represented take into account factors important for the existence of game, in particular small game.

scholarly journals Partitioning private and external benefits of crop pollination services

2020 ◽  
Vol 2 (3) ◽  
pp. 811-820
Author(s):  
Eric V. Lonsdorf ◽  
Insu Koh ◽  
Taylor Ricketts
Keyword(s):  
Crop Pollination ◽  
Pollination Services
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