The Responsibility of Farmers,Public Authorities and Consumers for Safeguarding Bees Against Harmful Pesticides

Journal of Agricultural and Environmental Ethics - This study examines the influence of environmental values on consumer intentions to participate in agritourism through the theory of planned...     

Simulation of Nitrogen Dynamics and Fluxes in Contrasting Catchments in Norway by Applying the Integrated Nitrogen Model for Catchments (INCA)

The process-based INCA model was applied to Dalelva Brook (3.2 km²) and the Bjerkreim River (685 km²) including several subcatchments, in order to test the model's ability to simulate streamwater nitrate (NO₃ ^-) dynamics and output fluxes under highly contrasting climatic conditions and nitrogen (N) loading. The simulated runoff volumes and mean NO₃ ^- concentrations at Dalelva and Bjerkreimwere within +2 to +10% of the measured average during 1993–1995 (–19 to +31% within individual years). INCA to a great extent also reproduced the observed streamwater flow dynamics at both study sites (coefficient of determination, r ² > 0.70). Temporal variation of streamwater NO₃ ^- during 1993–1995 was captured quite well by the model, especially at small catchments with a distinct seasonal NO₃ ^- pattern (r ² = 0.46–0.68). At the Bjerkreim River outlet, the relationship were somewhat weaker (r ² = 0.26, p < 0.01). Despite a few situations where the model failed to capturethe streamwater NO₃ ^- dynamics, INCA proved to be a quite robust tool for simulating NO₃ ^- dynamics and output fluxes in the two study catchments.     

Nonparametric spatial covariance functions: Estimation and testing

Spatial autocorrelation techniques are commonly used to describe genetic and ecological patterns. To improve statistical inference about spatial covariance, we propose a continuous nonparametric estimator of the covariance function in place of the spatial correlogram. The spline correlogram is an adaptation of a recent development in spatial statistics and is a generalization of the commonly used correlogram. We propose a bootstrap algorithm to erect a confidence envelope around the entire covariance function. The meaning of this envelope is discussed. Not all functions that can be drawn inside the envelope are candidate covariance functions, as they may not be positive semidefinite. However, covariance functions that do not fit, are not supported by the data. A direct estimate of the L₀ spatial correlation length with associated confidence interval is offered and its interpretation is discussed. The spline correlogram is found to have high precision when applied to synthetic data. For illustration, the method is applied to electrophoretic data of an alpine grass (Poa alpina).     

Recent Changes in Body Size of the Eurasian Otter <Emphasis Type="Italic">Lutra lutra</Emphasis> in Sweden

We studied geographical and temporal body size trends among 169 adult museum specimens of the Eurasian otter (Lutra lutra) collected in Sweden between 1962 and 2008, whose sex, year of collection, and locality were known. Skull size and body mass increased significantly in relation to the year of collection, and skull size (but not body mass) was significantly and negatively related to latitude, contrasting Bergmann’s rule and the trend found for Norwegian otters. Latitudinal differences in body size between the two countries may be due to differences in food availability. The temporal increase in body size among Swedish otters resembled that observed for Norway otters, though Swedish otters are smaller with respect to their Norwegian counterparts. Latitude and year represent a combination of environmental factors, including ambient temperature in the year of collection as well as the number of days of ice coverage. We replaced the above factors with mean annual temperature or the number of days of ice coverage, and found that each of these factors explains a similar proportion of the variation in body size as did latitude and year. We hypothesize that this temporal increase in body size is related to a combination of factors, including reduced energy expenditure resulting from increasing ambient temperature, and increased food availability from longer ice-free periods.     

An evaluation of two fluorescence screening methods for the determination of chrysene metabolites in fish bile

Two screening methods, synchronous fluorescence spectrometry (SFS) and high performance liquid chromatography with fluorescence detection (HPLC-F), have been evaluated for their suitability in determining chrysene metabolites in fish bile. The optimal wavelength pair, excitation/emission 272/374 nm, for SFS measurements of chrysene metabolites was identified by analysis of bile taken from fish exposed to the pure compound. This analysis revealed in addition some information about the metabolite pattern. However, when bile from fish exposed to complex and environmentally relevant mixtures of polycyclic aromatic hydrocarbons (PAHs) was analysed using these methods, identification of the chrysene metabolites was poor. Analysis of bile taken from fish exposed to single PAHs identified other three- and four-ring aromatics as the main interfering compounds. Both methods were equally able to discriminate between impacted and reference sites by determination of relative concentrations of fluorescent three- and four-ring aromatics.     

Description of the early development of the halibut Hippoglossus hippoglossus and attempts to rear the larvae past first feeding

Rearing experiments on the halibut Hippoglossus hippoglossus (L.) were carried out using gametes from parents caught at a depth of 600 to 700 m off the Norwegian coast in February 1980. After fertilization, the average egg diameter was 3.08 mm, average dry weight 1 038 μg and neutral buoyancy was at 36.5‰ S. The eggs hatched after 20 d at 4.7°C, 18 d at 5°C and 13 d at 7°C. Survival to hatching was better when antibiotics were used. At hatching the larvae were 6.4 mm long, there were no functional eyes or mouth, but prominent neuromast organs were present. Resorption of yolk lasted 50 d at 5.3°C; the eyes and mouth were then functioning and the larva was about 11.5 mm long. The larvae were offered zooplankton as food, but with little success in initial feeding. A few larvae fed and grew in 2 500-litre plastic bags, one reaching a length of 24 mm after 90 d.     

Diurnal and circadian rhythms in the turbidity of growing Skeletonema costatum cultures

Skeletonema costatum (Grev.) Cleve grown in batch culture at low light intensity under a 14 h light: 10 h dark photocycle showed exponential cell proliferation (1.1 doublings d^-1) without significant phasing of the cell division by the light: dark cycle. The growth in carbon concentration was, however, restricted to the light period. The turbidity of the culture closely followed the carbon oattern, and was not affected by the increase in the cell number during the dark period. It was found that a trustule suspension had only approximately 1% of the turbidity of the corresponding intact algae. Culture turbidity was therefore regarded as a biomass parameter similar to the carbon concentration, without direct correlation to the timing of the cell division. The short-time variations in the turbidity of growing algal cultures were further studied in a cage culture turbidostat. The growth rate (based on turbidity) increased rapidly during the first half of the light period, decreased slightly towards the evening and was zero throughout the dark period. When transformed to continuous light, the growth of the culture continued to show damped oscillations for up to 1 wk, but with a period of 26.7 h instead of 24 h. The same circadian rhythm was observed in chlorophyll content, and is thus possibly a reflection of a freely oscillating internal biological clock. The cage culture turbidostat was found to be a suitable device for studies of the photocycle related regulation of biosynthesis in S. costatum.     

Lynx Body Size in Norway is Related to its Main Prey (Roe Deer) Density,Climate, and Latitude

We studied the effect of various factors on body size variation of the Eurasian lynx in Norway, using data from 374 lynx collected between 1960 and 1976 and whose locality of capture, year of birth, sex, and age were known. Body size of lynx in Norway was mainly affected by sex and age. Female skull size (and by implication body size) was also positively affected by the availability of its main prey (roe deer) and by latitude, and negatively by the North Atlantic Oscillation (NAO). Male size was not affected by any of the environmental factors examined. We interpret the effects of NAO and latitude on body size through their effect on the local climate and particularly snow conditions. We suggest that females are more sensitive to environmental factors than males.