Nitrogen saturation induced during winter by experimental NH4NO3 addition to a forested catchment

To investigate the potential risk of 'nitrogen saturation' in Scandinavian boreal forests, the authors are experimentally adding 30-50 kg N ha(-1) year(-1) as NH4NO3 in precipitation to an entire 0.52-ha 80-year-old spruce forested catchment at G?rdsj?n, near Gothenburg on the Swedish west coast. NO3 concentrations in runoff increased from 0 to about 7 microeq liter(-1) (maximum pulse of 43 microeq liter(-1)). The increase occurred in winter; during the April-October growing season, NO3 concentrations were very low. The speed of the response suggests that these forests are already close to saturation.     

Foraging responses in the butterflies <Emphasis Type="Italic">Inachis io</Emphasis>, <Emphasis Type="Italic">Aglais urticae</Emphasis> (Nymphalidae), and <Emphasis Type="Italic">Gonepteryx rhamni</Emphasis> (Pieridae) to floral scents

Summary. For butterflies to be efficient foragers, they need to be able to recognize rewarding flowers. Flower signals such as colours and scents assist this recognition process. For plant species to attract and keep butterflies as pollinators, species-specific floral signals are crucial. The aim of this study is to investigate foraging responses to floral scents in three temperate butterfly species, Inachis io L. (Nymphalidae), Aglais urticae L. (Nymphalidae), and Gonepteryx rhamni L. (Pieridae), in behavioural choice bioassays. The butterflies were allowed to choose bet-ween flower models varying in scent and colour (mauve or green). Flowers or vegetative parts from the plants Centaurea scabiosa L. (Asteraceae), Cirsium arvense (L.) (Asteraceae), Knautia arvensis (L.) (Dipsacaceae), Buddleja davidii Franchet (Loganicaeae), Origanum vulgareL. (Lamiaceae), Achillea millefolium L. (Asteraceae), and Philadelphus coronarius L. (Hydrangiaceae) were used as scent sources. All visits to the models — those that included probing and those that did not — were counted, as was the duration of these behaviours. Both flower-naive and flower-experienced (conditioned to sugar-water rewards, the colour mauve, and specific floral scents) butterflies were tested for their preference for floral versus vegetative scents, and to floral scent versus colour. The butterflies were also tested for their ability to switch floral scent preferences in response to rewards. Flower-naive butterflies demonstrated a preference for the floral scent of the butterfly-favourable plants C. arvense and K. arvensis over the floral scent of the non-favourable plants Achillea millefolium (Asteraceae), and Philadelphus coronarius cv. (Hydrangiaceae). Most of the butterflies that were conditioned to floral scents of either C. arvense, K. arvensis, or B. davidii readily switched theirfloral scent preferences to the one most recently associated with reward, thus demonstrating that floral scent constancy is a result from learning. These findings suggest that these butterflies use floral scent as an important cue signal to initially identify and subsequently recognize and distinguish among rewarding plants. Received 2 September 2001; accepted 9 September 2002.     

Genomics meets ethology: a new route to understanding domestication, behavior, and sustainability in animal breeding

Animal behavior is a central part of animal welfare, a keystone in sustainable animal breeding. During domestication, animals have adapted with respect to behavior and an array of other traits. We compared the behavior of junglefowl and White Leghorn layers, selected for egg production (and indirectly for growth). Jungle-fowl had a more active behavior in social, exploratory, anti-predatory, and feeding tests. A genome scan for Quantitative Trait Loci (QTLs) in a junglefowl x White Leghorn intercross revealed several significant or suggestive QTLs for different traits. Some production QTLs coincided with QTLs for behavior, suggesting that pleiotropic effects may be important for the development of domestication phenotypes. One gene has been located, which has a strong effect on the risk of being a victim of feather pecking, a detrimental behavior disorder. Modern genomics paired with analysis of behavior may help in designing more sustainable and robust breeding in the future.     

Evaluation of solid sorbents for sampling nitroglycerin,ethylene glycol dinitrate and isopropyl nitrate in work-room air

Activated charcoal, Amberlite XAD-2, and Amberlite XAD-7 have been evaluated for the solid sampling of airborne nitroglycerin, ethylene glycol dinitrate and isopropyl nitrate. With the use of diethyl ether for solvent desorption, XAD-2 was found superior for sampling nitroglycerin and ethylene glycol dinitrate. Both XAD-7 and activated charcoal gave high recoveries for isopropyl nitrate; charcoal had a greater capacity than XAD-7 for this compound, however.     

Evaluation of solid sorbents for sampling aliphatic and aromatic nitro compounds in work-room air

Amberlite XAD-2 and XAD-7 porous polymers were evaluated for the solid sampling of aliphatic and aromatic nitro compounds in work-room air. With the use of solvent desorption, XAD-2 gave 80–100% recovery of nitroaromatics, and XAD-7 85–100% recovery of nitroaliphatics. The compounds studied were nitromethane, nitroethane, 2-nitropropane, nitrobenzene, $\text{m}$-dinitrobenzene and 2,4,6-trinitrotoluene. All six compounds gave very poor recoveries from activated charcoal.     

Farm cooperation to improve sustainability

In this paper, it is demonstrated that partnership arrangements between farmers might be a way to secure the economic viability of their farms as well as to increase profitability. The article discusses empirical analyses of three different forms of collaboration, with an emphasis on the environmental improvements associated with collaboration. Collaboration between a dairy farm and a crop farm is analyzed in the first case. The results show that potential gains from improved diversification and crop rotation are substantial, and even larger when the collaboration also involves machinery. The second analysis considers external integration between farrowing and finishing-pig operations. Gains from collaboration originate from biological and technical factors, such as improved growth rate of the pigs and better utilization of buildings. Finally, an evaluation of a group of collaborating crop farmers is performed. In this case, the benefits that arise are mainly due to reduced machinery costs and/or gains due to other factors, such as improved crop rotation and managerial/marketing strategies.     

Female egg investment in relation to male sexual traits and the potential for transgenerational effects in sexual selection

Life-history theory predicts that individuals should increase their reproductive effort when the fitness return from reproduction is high. Females mated with high-quality males are therefore expected to have higher investment than females mated with low-quality males, which could bias estimates of paternal effects. Investigating the traits females use in their allocation decisions and the aspects of reproduction that are altered is essential for understanding how sexual selection is affected. We studied the potential for differential female allocation in a captive population of a precocial bird, the Chinese quail, Coturnix chinensis. Females paired with males with large sexual ornaments laid larger, but not more, eggs than females paired with males with small sexual ornaments. Furthermore, female egg mass was also significantly positively affected by male testis size, probably via some unknown effect of testis size on male phenotype. Testis size and ornament size were not correlated. Thus, both primary and secondary male sexual traits could be important components of female allocation decisions. Experimental manipulation of hormone levels during embryonic development showed that both male and female traits influencing female egg size were sensitive to early hormone exposure. Differences in prenatal hormone exposure as a result of maternal steroid allocation to eggs may explain some of the variation in reproductive success among individuals, with important implications for non-genetic transgenerational effects in sexual selection.Communicated by C. Brown     

Inter-annual Variations of Ozone and Nitrogen Dioxide Over Europe During 1958–2003 Simulated with a Regional CTM

Inter-annual variability of surface ozone (O₃) and nitrogen dioxide (NO₂) over Europe has been studied over the period 1958–2003 using a three-dimensional Chemistry-Transport Model coupled to meteorological data from the ERA40 data set produced at the European Centre of Medium-range Weather Forecasts (ECMWF). Emissions and boundary conditions were kept at present levels throughout the simulation period. It was found that the annual mean NO₂ concentration varies between ±50% and the summer mean O₃ concentration varies between −10 and +20 percent (%) compared to the 46-year average over the model domain. There is also variation in ozone and NO₂ over longer time scales. The last 22 years display high concentrations of ozone in central and south-western Europe and low concentrations in north-eastern Europe. The first 22 years display very high concentrations of NO₂ over the North Sea. There is indication of trends in ozone and nitrogen dioxide but this has to be investigated further. Such information is one factor that should be taken into account when considering future control strategies.     

Atmospheric mercury at mediterranean coastal stations

Mercury in air has been measured at five coastal Mediterranean sites, involving measurements in Spain, France, Italy, Slovenia and Israel. Four two-weeks long measurements campaigns were performed at the five sites. The measurements were carried out during autumn 2003 and winter, spring and summer 2004. Total gaseous mercury/elemental gaseous mercury, particulate mercury and divalent gaseous mercury were measured in parallel at the five sites. The activities constituted a subtask of the EU funded MERCYMS research project, which also included Mediterranean Sea cruises where both mercury in air and water were measured. The result from an evaluation of all the coastal air data is presented. Mercury concentrations from the different sites are compared with similar data obtained in northern Europe and elsewhere. The result shows that the background concentration of mercury in Mediterranean coastal air is lower than earlier anticipated. Background concentrations of TGM, RGM and TPM corresponded to 1.75–1.80 ng m⁻³, 1–13 and 3–23 pg m⁻³, respectively. The measurements also showed that the mercury concentration occasionally can be very high in some areas due to local anthropogenic emissions. It is proposed that diurnal variation in RGM concentrations observed during situation with nocturnal inversion merely is an effect of meteorology rather than due to local photochemistry.