Search results for "pöly"
showing 10 items of 16 documents
The interplay of landscape composition and configuration: new pathways to manage functional biodiversity and agroecosystem services across Europe
2019
Managing agricultural landscapes to support biodiversity and ecosystem services is a key aim of a sustainable agriculture. However, how the spatial arrangement of crop fields and other habitats in landscapes impacts arthropods and their functions is poorly known. Synthesising data from 49 studies (1515 landscapes) across Europe, we examined effects of landscape composition (% habitats) and configuration (edge density) on arthropods in fields and their margins, pest control, pollination and yields. Configuration effects interacted with the proportions of crop and non-crop habitats, and species’ dietary, dispersal and overwintering traits led to contrasting responses to landscape variables. O…
Alder pollen in Finland ripens after a short exposure to warm days in early spring, showing biennial variation in the onset of pollen ripening
2017
Abstract We developed a temperature sum model to predict the daily pollen release of alder, based on pollen data collected with pollen traps at seven locations in Finland over the years 2000–2014. We estimated the model parameters by minimizing the sum of squared errors (SSE) of the model, with weights that put more weight on binary recognition of daily presence or absence of pollen. The model results suggest that alder pollen ripens after a couple of warm days in February, while the whole pollen release period typically takes up to 4 weeks. We tested the model residuals against air humidity, precipitation and wind speed, but adding these meteorological features did not improve the model pr…
Foraging Bumblebees Selectively Attend to Other Types of Bees Based on Their Reward-Predictive Value.
2020
Using social information can be an efficient strategy for learning in a new environment while reducing the risks associated with trial-and-error learning. Whereas social information from conspecifics has long been assumed to be preferentially attended by animals, heterospecifics can also provide relevant information. Because different species may vary in their informative value, using heterospecific social information indiscriminately can be ineffective and even detrimental. Here, we evaluated how selective use of social information might arise at a proximate level in bumblebees (Bombus terrestris) as a result of experience with demonstrators differing in their visual appearance and in thei…
Comparison of quantitative Holocene temperature reconstructions using multiple proxies from a northern boreal lake
2017
Four biotic proxies (plant macrofossils, pollen, chironomids and diatoms) are employed to quantitatively reconstruct variations in mean July air temperatures ( Tjul) at Lake Loitsana (northern Finland) during the Holocene. The aim is to evaluate the robustness and biases in these temperature reconstructions and to compare the timing of highest Tjul in the individual reconstructions. The reconstructed Tjul values are evaluated in relation to local-scale/site-specific processes associated with the Holocene lake development at Loitsana as these factors have been shown to significantly influence the fossil assemblages found in the Lake Loitsana sediments. While pollen-based temperatures follow…
DNA traces the origin of honey by identifying plants, bacteria and fungi
2021
The regional origin of a food product commonly affects its value. To this, DNA-based identification of tissue remains could offer fine resolution. For honey, this would allow the usage of not only pollen but all plant tissue, and also that of microbes in the product, for discerning the origin. Here we examined how plant, bacterial and fungal taxa identified by DNA metabarcoding and metagenomics differentiate between honey samples from three neighbouring countries. To establish how the taxonomic contents of honey reflect the country of origin, we used joint species distribution modelling. At the lowest taxonomic level by metabarcoding, with operational taxonomic units, the country of origin …
Effects of waste treatment technique and quality of waste on bioaerosols in Finnish waste treatment plants
2004
Outi Tolvanen selvitti tutkimuksessaan mikrobi-, endotoksiini- ja pölypitoisuuksia suomalaisilla jätteenkäsittelylaitoksilla. Tolvanen tutki, onko jätteiden tehostunut syntypistelajittelu ja jätteiden käsittely suljetuissa laitoksissa vähentänyt bioaerosolien ja pölyn aiheuttamia työhygieenisiä ongelmia. Kohonneiden mikrobipitoisuuksien on aikaisemmissa tutkimuksissa havaittu aiheuttavan jätteitä työssään käsitteleville henkilöille erilaisia oireita, kuten pahoinvointia, päänsärkyä, kuumeilua sekä allergiaa ja astmaa. The last fifteen years have seen immense changes in waste treatment in Finland. The number of landfill sites has been reduced and new waste treatment plants have been construc…
Geranium sylvaticum increases pollination probability by sexually dimorphic flowers
2022
Sexual dimorphism is expressed as different morphologies between the sexes of a species. Dimorphism is pronounced in gynodioecious populations which consist of female and hermaphrodite individuals. The small size of female flowers in gynodioecious species is often explained by resource re-allocation to seed production instead of large flowers. However, pollinator attraction is critical to female fitness, and factors other than resource savings are needed to explain the small size of female flowers. We hypothesized that the floral size dimorphism in the perennial gynodioecious Geranium sylvaticum (L.) is adaptive in terms of pollination. To test this “pollination hypothesis,” we video record…
Geranium sylvaticum video recording data
2022
Dataset consists of three sheets. Insect visits data is the main data with insect visitors per visitor group, and their reproductive organ contacts during each visit. Seed data is the data of count seeds of the study plants. Visitation rate is the data on the number of visits per flower per hour by different visitor groups.
The role of geitonogamy in the reproduction success of a nectarless dactylorhiza maculata (orchidaceae)
2011
Dactylorhiza maculata is a common terrestrial orchid in Finland. It is nectarless and the seed production is relatively high for a deceptive species. The pollinators of D. maculata do not have frequent visits to the flowers, but the species is capable of over 50 % seed capsule production. Geitonogamy is the transfer of self pollen between flowers on the same individual. It is typical that the pollinators of deceptive inflorescences visit only few flowers and have short stays in them, and therefore it is commonly thought that geitonogamy is infrequent among deceptive species. I examined the role of geitonogamy in the seed production of D. maculata. I prevented geitonogamy in male-sterilizati…