Visitor preferences of thinning practice in young even-aged stands of pedunculate oak (Quercus robur L.): comparing the opinion of forestry professionals in six European countries

This study compared visitor preferences of forestry professionals across six European countries (Sweden, Denmark, Great Britain, Austria, Romania and Portugal) using a questionnaire survey. The 598 interviewees were asked to rank photographs depicting recently thinned experimental plots in a 13-year old stand of pedunculate oak (Quercus robur L.) according to the criterion: “Which forest environment do you prefer as a visitor?” The plots represented five different residual stem densities: 7000 (no thinning, very high stem density), 5300 (heavy thinning, high stem density), 1000 (very heavy thinning, medium stem density), 300 (extremely heavy thinning, low stem density/open stand) and 100 (solitary trees, very low stem density/very open stand) stems ha^?1. The results indicated geographical variation in the preferences for different thinning practices in young stands of oak. Portuguese, Austrian and Romanian respondents generally favoured thinned, but dense stands, whereas Danish and British respondents preferred very heavily thinned stands. Swedish respondents preferred open stands resulting from extremely heavy thinning. Photographs taken along rows were favoured to photographs across rows, indicating a preference for scenes offering perspective and accessibility. The results indicate a variation of visitor preferences among forestry professionals for different silvicultural regimes. We interpret this in the context of national traditions and forestry paradigms that influence the shaping of preferences.     

Application of sorbents in different soil types from small arms shooting ranges for immobilization of lead (Pb), copper (Cu), zinc (Zn), and antimony (Sb)

Journal of Soils and Sediments - Soil contamination of ammunition residues at shooting ranges for small arms may be followed by leaching of lead (Pb), copper (Cu), zinc (Zn), and antimony (Sb)....     

Trends and drivers of on-farm conservation of the root legume ahipa (<Emphasis Type="Italic">Pachyrhizus ahipa</Emphasis>) in Bolivia over the period 1994/96–2012

The leguminous Andean root crop ahipa has become scarce and the current status of in situ conservation in Bolivia is concerning. Agro-biodiversity changes affect the use, conservation and socio-economic trends for ahipa (Pachyrhizus ahipa) and to substantiate this, a comparison of two cropping periods were made. Aspects of root production and the shift from cultivation of ahipa to cash crops such as maize were compared for two periods: (a) 1994/96 and (b) 2012. Our study showed that the price of ahipa had not increased in 70% of the urban markets; hence, there is little incentive to retain the cultivation of ahipa. We found that rural ahipa growers selected the largest seeds, but did not select seeds by colour. The mixed seed colour predominated the conservation of ahipa. Laborious yield enhancing practices required in field management and low market value endanger future conservation of the ahipa. We conclude that additional research is needed in order to safeguard the extant variation of ahipa, i.e. nutritional value, taste, stress tolerance and market potential.     

Farm and operator characteristics affecting adoption of precision agriculture in Denmark and Germany

Precision Agriculture (PA) has been advocated as a promising technology and management philosophy that provides multidimensional benefits for producers and consumers while being environmentally friendly. In Europe, private stakeholders (farm advisors, farm equipment producers, decision support providers, farmers) and research institutions have been trying to develop, test and demonstrate adoption of precision agriculture solutions with governments financing big projects in these areas. Despite these efforts, adoption is still lagging behind expectations.

Whether farmers adopt PA or not is likely to be influenced by several factors. This study intends to identify the main socio-economic determinants of adoption of precision agriculture in Denmark and Germany employing a binary logit model on a cross-section survey data. The results show that farm size, farmer age and demonstration and networking events like attending workshops and exhibitions significantly influence farmers’ adoption decision.     

Apple rootstocks may become infected by Neonectria ditissima during propagation

Introduction and purpose: The ability of apple rootstocks to become infected by Neonectria ditissima, the cause of European canker, was studied over two years.

Materials and methods: Rootstocks B9 and M9 with a size suitable for grafting (6-10 mm stem diameter, termed rootstocks), and smaller sized rootstocks (<5 mm stem diameter, termed transplants) of B9, M9, M26, MM106 and Antonovka were inoculated with N. ditissima at different times, either with contaminated map pins or with spore suspensions. In addition, the rootstocks were either defeathered (side shoots removed), topped (top shoot headed) or both, to create wounds that would normally occur during propagation, while wounds on transplants were made by removing leaves.

Results and discussion: One month after inoculation, slightly sunken canker lesions had developed around the inoculation points of the map pins or wounds. No lesions developed on the non-inoculated controls. Map pin inoculation resulted in 30% to 89% infection and spore suspension sprayed on wounds from 5% to 45% infection. When the cankered areas were split open, brown lesions with necrotic tissue due to infection by N. ditissima appeared. The transplants of M9, M26 and MM106 inoculated with contaminated map pins in 2014 developed necrosis on 40% to 67% of the plants, but there were no differences in the incidence or severity among the different types. On the transplants of B9, Antonovka and M9 inoculated in 2015, there was more necrosis on B9 (42%) than on Antonovka (11%) and more sporulating lesions on B9 (29%) than on M9 (9%) or on Antonovka (4%).

Conclusion: It can be concluded that rootstocks used for apple trees may become infected by N. ditissima, and wounds should thus be protected during propagation.     

Haematogenous septic arthritis in foals: Short‐ and long‐term outcome and analysis of factors affecting prognosis

Synovial sepsis represents a major cause of morbidity and mortality in foals; however, there are no studies focusing on foals particularly at risk during the first 2 months of life. Our objective was to analyse outcome in foals aged <2 months with haematogenous septic arthritis and to identify prognostic factors and compare the effects of two different lavage procedures on outcome. Sixty foals with synovial sepsis were used for our retrospective study in which medical records, online data and telephone interviews were utilised to analyse prognostic factors, and determine short‐ and long‐term survival and athletic performance of foals treated at Evidensia Equine Specialist Hospital, Helsingborg, between 2008 and 2014. Overall survival to discharge was 80% (48/60). Time to long‐term follow‐up ranged from 6 months to 6.5 years. Forty/60 (67%) horses survived long‐term. Four/8 (50%) of the nonsurvivors at long‐term follow‐up had been subjected to euthanasia due to sequelae of joint sepsis. Of the long‐term survivors, 37/40 (92.5%) achieved athletic soundness. Overall long‐term outcome for athletic soundness was 37/60 (62%). Prognostic factors based on historical, clinical or laboratory data, or the use of through‐and‐through needle lavage compared to endoscopic lavage as the first procedure, could not be identified. The present study demonstrates a more favourable prognosis than previously reported, with 80% of foals with synovial sepsis surviving to discharge, and approximately 60% achieving athletic soundness. However, the study was limited by a small population size, which may account for the failure to verify statistically significant prognostic factors.     

Physiological limit of the daily endogenous cholecalciferol synthesis from UV light in cattle

The link between UV light (sunlight) and endogenous cholecalciferol (vitamin D₃) synthesis in the skin of humans has been known for more than a 100 years, since doctors for the first time successfully used UV light to cure rickets in children. Years later, it was shown that UV light also had a significant effect on the cholecalciferol status in the body of cattle. The cholecalciferol status in the body is measured as the plasma concentration of 25‐hydroxycholecalciferol, which in cattle and humans is the major circulating metabolite of cholecalciferol. Very little is, however, known about the quantitative efficiency of UV light as a source of cholecalciferol in cattle nutrition and physiology. Hence, the aim of this study was to determine the efficiency of using UV light for increasing the plasma 25‐hydroxycholecalciferol concentration in cholecalciferol‐deprived cattle. Twelve cows deprived of cholecalciferol for 6 months were divided into three treatment groups and exposed to UV light for 30, 90 or 120 min/day during 28 days. UV‐light wavelengths ranged from 280 to 415 nm and 30‐min exposure to the UV light was equivalent to 60‐min average summer‐sunlight exposure at 56 °N. Blood samples were collected every 3–4 days and analysed for 25‐hydroxycholecalciferol and cholecalciferol. Results showed that increasing the exposure time from 90–120 min/day did not change the slope of the daily increase in plasma 25‐hydroxycholecalciferol. Hence, it appears that cholecalciferol‐deprived dairy cattle are able to increase their plasma 25‐hydroxycholecalciferol concentration by a maximum of 1 ng/ml/day from UV‐light exposure.     

Monitoring of oxygen fluctuations in seabass cages (Dicentrarchus labrax L.) in a commercial fish farm in Greece

Dissolved oxygen and temperature were monitored in cages stocked seabass at a commercial fish farm in Greece during summer and autumn. During the first part of the study, October–November 2012, current velocity monitoring outside the cages supported the sampling program. The latter sampling took place during May–July 2014. Including both periods, temperature fluctuated within the range 18–26°C while the current velocity, dominated by the tidal flow, varied from 0 to 28 cm/s in autumn. During sampling, seabass of 400–550 g individual weight was stocked at a density of 10–15 kg/m³. Within the cages, dissolved oxygen (DO) saturation decreased by 10% to 50% compared with outside levels. In‐cage oxygen concentrations seemed to be affected by current speed, temperature and diurnal fluctuations due to the fish stock's activity and the day‐night rhythm of algae. Hypoxia within the range 40%–70% of oxygen saturation was shown in several cases, despite the fact that the feeding intensity was quite low in the farm. The diurnal pattern of DO saturation showed that minimum levels coincided with feeding of the fish, while photosynthesis played a minor role in this case. This level of DO saturation although does not result in any mortalities may have other severe implications, especially at high temperature, such as lower feed utilization, increased metabolic expenses due to osmo‐respiratory compromise, increased stress level, lower disease resistance and diminished fish welfare.     

Early introduction of an inert diet and unenriched Artemia enhances growth and quality of Atlantic cod (Gadus morhua) larvae

The effects of two weaning diets and different weaning protocols on growth, survival, skeletal deformity and gut morphology of Atlantic cod larvae were studied in four groups from 16 to 45 days posthatch (dph). Cod larvae in groups 1 (early weaning with control diet) and 2 (early weaning with experimental diet) were used to evaluate the effects of different polar lipid content of weaning diets on larval and juvenile performance. Cod larvae in groups 2, 3 (early weaning with experimental diet + cofeeding with Artemia) and 4 (earlier weaning with experimental diet and earlier cofeeding with Artemia) were used to evaluate the effects of early introduction of dry diet and Artemia. From 45 to 170 dph, cod juveniles from all four groups were reared using a standard feeding protocol. No significant differences in growth, survival, deformities and gut morphology were found between cod larvae and juveniles from groups 1 and 2. Cod larvae fed on cofeeding regime with Artemia nauplii (groups 3 and 4) were bigger and had lower frequencies of jaw and neck deformities and higher foregut microvillus circumference than cod larvae from group 2. Our results demonstrate the importance of proper weaning protocols in producing better quality cod juveniles.