496 research outputs found

    Simple modification of two-equation models for non-neutral flow

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    Exploring the link between farmers’ entrepreneurial identities and work wellbeing

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    Pressure on farmers to behave more ‘entrepreneurial’ is increasing. Psychological and social science research therefore has examined what characterises farmers identifying as entrepreneurs. A previous study in Finland suggested that farmers' self-identities may conflict with the public paradigm describing farmers as entrepreneurs instead of food providers. Different expectations towards farming may cause identity issues and decrease work wellbeing. The present study examines the relationship of work wellbeing and entrepreneurial identification. Utilizing the Maslach Burnout Inventory and the theory of Entrepreneurial Identity, the results show that work wellbeing is higher for diversified farmers and rural business owners than for conventional farmers in Finland. Conventional farmers on the other hand experience higher rates of loss of personal control and self-efficacy, indicating that the political strategies for entrepreneurs, diversification and innovativeness, are not applicable to all farmer groups. Entrepreneurs aim for autonomy and personal control which generally may be limited in specialised, subsidy-dependent agricultural production systems. Identity formation processes and how farmers can gain more control over their businesses as well as the limitations of entrepreneurship in the momentary agricultural policy system, should be considered in upcoming policy strategies.Peer reviewe

    Technical note : Comparison of methane ebullition modelling approaches used in terrestrial wetland models

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    Emission via bubbling, i.e. ebullition, is one of the main methane (CH4) emission pathways from wetlands to the atmosphere. Direct measurement of gas bubble formation, growth and release in the peat-water matrix is challenging and in consequence these processes are relatively unknown and are coarsely represented in current wetland CH4 emission models. In this study we aimed to evaluate three ebullition modelling approaches and their effect on model performance. This was achieved by implementing the three approaches in one process-based CH4 emission model. All the approaches were based on some kind of threshold: either on CH4 pore water concentration (ECT), pressure (EPT) or free-phase gas volume (EBG) threshold. The model was run using 4 years of data from a boreal sedge fen and the results were compared with eddy covariance measurements of CH4 fluxes. Modelled annual CH4 emissions were largely unaffected by the different ebullition modelling approaches; however, temporal variability in CH4 emissions varied an order of magnitude between the approaches. Hence the ebullition modelling approach drives the temporal variability in modelled CH4 emissions and therefore significantly impacts, for instance, high-frequency (daily scale) model comparison and calibration against measurements. The modelling approach based on the most recent knowledge of the ebullition process (volume threshold, EBG) agreed the best with the measured fluxes (R-2 = 0.63) and hence produced the most reasonable results, although there was a scale mismatch between the measurements (ecosystem scale with heterogeneous ebullition locations) and model results (single horizontally ho-mogeneous peat column). The approach should be favoured over the two other more widely used ebullition modelling approaches and researchers are encouraged to implement it into their CH4 emission models.Peer reviewe

    Farmer's attitudes affect piglet production parameters

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    Our results show that farmers' attitudes count: treating the animals humanely, investing in a favourable environment, and having a positive attitude towards new information and scientific research is associated with an above-average productivity on piglet farms. These attitudes, when implemented and concretized in practice, also benefit the animals through a higher standard of welfare

    Small spatial variability in methane emission measured from a wet patterned boreal bog

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    We measured methane fluxes of a patterned bog situated in Siikaneva in southern Finland from six different plant community types in three growing seasons (2012-2014) using the static chamber method with chamber exposure of 35 min. A mixed-effects model was applied to quantify the effect of the controlling factors on the methane flux. The plant community types differed from each other in their water level, species composition, total leaf area (LAI(TOT)) and leaf area of aerenchymatous plant species (LAI(AER)). Methane emissions ranged from -309 to 1254 mg m(-2) d(-1). Although methane fluxes increased with increasing peat temperature, LAI(TOT) and LAI(AER), they had no correlation with water table or with plant community type. The only exception was higher fluxes from hummocks and high lawns than from high hummocks and bare peat surfaces in 2013 and from bare peat surfaces than from high hummocks in 2014. Chamber fluxes upscaled to ecosystem level for the peak season were of the same magnitude as the fluxes measured with the eddy covariance (EC) technique. In 2012 and in August 2014 there was a good agreement between the two methods; in 2013 and in July 2014, the chamber fluxes were higher than the EC fluxes. Net fluxes to soil, indicating higher methane oxidation than production, were detected every year and in all community types. Our results underline the importance of both LAI(AER) and LAI(TOT) in controlling methane fluxes and indicate the need for automatized chambers to reliably capture localized events to support the more robust EC method.Peer reviewe

    Canopy uptake dominates nighttime carbonyl sulfide fluxes in a boreal forest

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    Nighttime vegetative uptake of carbonyl sulfide (COS) can exist due to the incomplete closure of stomata and the light independence of the enzyme carbonic anhydrase, which complicates the use of COS as a tracer for gross primary productivity (GPP). In this study we derived nighttime COS fluxes in a boreal forest (the SMEAR II station in Hyytiälä, Finland; 61°51′ N, 24°17′ E; 181 m a.s.l.) from June to November 2015 using two different methods: eddy-covariance (EC) measurements (FCOS-EC) and the radon-tracer method (FCOS-Rn). The total nighttime COS fluxes averaged over the whole measurement period were −6.8 ± 2.2 and −7.9 ± 3.8 pmol m−2 s−1 for FCOS-Rn and FCOS-EC, respectively, which is 33–38 % of the average daytime fluxes and 21 % of the total daily COS uptake. The correlation of 222Rn (of which the source is the soil) with COS (average R2  =  0.58) was lower than with CO2 (0.70), suggesting that the main sink of COS is not located at the ground. These observations are supported by soil chamber measurements that show that soil contributes to only 34–40 % of the total nighttime COS uptake. We found a decrease in COS uptake with decreasing nighttime stomatal conductance and increasing vapor-pressure deficit and air temperature, driven by stomatal closure in response to a warm and dry period in August. We also discuss the effect that canopy layer mixing can have on the radon-tracer method and the sensitivity of (FCOS-EC) to atmospheric turbulence. Our results suggest that the nighttime uptake of COS is mainly driven by the tree foliage and is significant in a boreal forest, such that it needs to be taken into account when using COS as a tracer for GPP

    Vammaisten ihmisten työelämäosallisuus ja työssä koettu syrjintä: Vammaisfoorumin kyselyn 2018 tuloksia

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    CH4 and N2O dynamics in the boreal forest-mire ecotone

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