1,721,242 research outputs found
Data for "Willingness of rural and urban citizens to undertake pollinator conservation actions across three contrasting European countries"
No full text<p>Data for: "Willingness of rural and urban citizens to undertake pollinator conservation actions across three contrasting European countries" by Costanza Geppert, Cristiano Franceschinis, Thijs P.M. Fijen, David Kleijn, Jeroen Scheper, Ingolf Steffan-Dewenter, Mara Thiene, Lorenzo Marini (2024) <em>People and Nature</em>. This dataset was obtained by administering an online questionnaire in Germany, Italy, and the Netherlands.</p>
Seed set of male-sterile and male-fertile oilseed rape (Brassica napus) in relation to pollinator density
No full textThe effects of pollinator density on the seed set of a male-sterile (MS) and a
male-fertile (MF) line of winter oilseed rape (Brassica napus) were studied in 24
isolation cages (7.5 m). Pollinator treatments comprised of high pollinator density
(a small honeybee colony and 10 mason bees, Osmia rufa), and a gradient of increasing
O. rufa densities from zero (control) up to 100 bees per cage. High pollinator densities
increased the seed weight per plant from 6.5 g to 56.9 g for the MS line. However seed
weight did not differ between high pollinator densities and controls for the MF line.
Increasing densities of O. rufa had a significant effect on almost all yield components
of the MS line, but only marginal effects on the MF line. The number of seeds per pod,
the seed weight per plant and the harvest index (seed weight/plant dry weight)
of the MS line showed a significantly steeper increase with increasing bee density
than that of the MF line. The results suggest that solitary bees could be used
successfully to replace honeybees as pollinators of MS oilseed rape in isolation cages
Elevation and experimental snowmelt manipulation affect emergence phenology and abundance of soil‐hibernating arthropods
No full textThe influence of temperature and photoperiod on the timing of brood onset in hibernating honey bee colonies
No full textIn order to save resources, honey bee (Apis mellifera) colonies in the temperate zones stop brood rearing during winter. Brood rearing is resumed in late winter to build up a sufficient worker force that allows to exploit floral resources in upcoming spring. The timing of brood onset in hibernating colonies is crucial and a premature brood onset could lead to an early depletion of energy reservoirs. However, the mechanisms underlying the timing of brood onset and potential risks of mistiming in the course of ongoing climate change are not well understood. To assess the relative importance of ambient temperature and photoperiod as potential regulating factors for brood rearing activity in hibernating colonies, we overwintered 24 honey bee colonies within environmental chambers. The colonies were assigned to two different temperature treatments and three different photoperiod treatments to disentangle the individual and interacting effects of temperature and photoperiod. Tracking in-hive temperature as indicator for brood rearing activity revealed that increasing ambient temperature triggered brood onset. Under cold conditions, photoperiod alone did not affect brood onset, but the light regime altered the impact of higher ambient temperature on brood rearing activity. Further the number of brood rearing colonies increased with elapsed time which suggests the involvement of an internal clock. We conclude that timing of brood onset in late winter is mainly driven by temperature but modulated by photoperiod. Climate warming might change the interplay of these factors and result in mismatches of brood phenology and environmental conditions.</jats:p
Appendix B. Effects of population size on rate of parasitism of O. rufa populations during the study period, 1998–2003.
No full textEffects of population size on rate of parasitism of O. rufa populations during the study period, 1998–2003
Appendix C. Time series analyses of effects of population size on population growth rates.
No full textTime series analyses of effects of population size on population growth rates
The influence of temperature and photoperiod on the timing of brood onset in hibernating honey bee colonies
No full textIn order to save resources, honey bee (Apis mellifera) colonies in the temperate zones stop brood rearing during winter. Brood rearing is resumed in late winter to build up a sufficient worker force that allows to exploit floral resources in upcoming spring. The timing of brood onset in hibernating colonies is crucial and a premature brood onset could lead to an early depletion of energy reservoirs. However, the mechanisms underlying the timing of brood onset and potential risks of mistiming in the course of ongoing climate change are not well understood. To assess the relative importance of ambient temperature and photoperiod as potential regulating factors for brood rearing activity in hibernating colonies, we overwintered 24 honey bee colonies within environmental chambers. The colonies were assigned to two different temperature treatments and three different photoperiod treatments to disentangle the individual and interacting effects of temperature and photoperiod. Tracking in-hive temperature as indicator for brood rearing activity revealed that increasing ambient temperature triggered brood onset. Under cold conditions, photoperiod alone did not affect brood onset, but the light regime altered the impact of higher ambient temperature on brood rearing activity. Further the number of brood rearing colonies increased with elapsed time which suggests the involvement of an internal clock. We conclude that timing of brood onset in late winter is mainly driven by temperature but modulated by photoperiod. Climate warming might change the interplay of these factors and result in mismatches of brood phenology and environmental conditions
Appendix A. Abundance and biotic interactions of Osmia rufa populations, and percentage brood cells of O. rufa, other bees, and wasps in trap nests from 1998 to 2003.
No full textAbundance and biotic interactions of Osmia rufa populations, and percentage brood cells of O. rufa, other bees, and wasps in trap nests from 1998 to 2003
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