Morphology and vegetation of a dune system in SE Denmark in relation to climate change and sea level rise

Recordings by the Danish Meteorological Institute show, that the mean temperature of Denmark has remained fairly constant and the mean precipitation in winter has increased very slightly during the last c. 100 years, and that the relative sea level rise in Danish waters amounted to between + 9 cm and -3 cm during the same period of time.For the W Baltic area a doubling of CO₂-level in the atmosphere is predicted to cause an increase in mean temperature by 3–4°C, an increase in length of growing season by c. 55 days, an increase in aridity, and a sea level rise of between 25 and 165 cm. Based on recent observations of morphology, soil and vegetation of a W Baltic dune system, possible effects of these changes upon vegetational composition, phytogeography, nutrient economy, stability, and ground water level of coastal dunes are discussed.     

New woodlands in Denmark: The role of private landowners

Voluntary schemes that offer payments to farmers who agree to desist from certain damaging operations or carrying out environmentally sensitive activities have become an integral part of current European agricultural policy. These schemes tend to operate from the presumption of an economically rational behaviour of the landowner obtaining the grant. Analysis of landowners using the Danish subsidy scheme for field afforestation (EU regulation 2080/92) has shown that there is a need to reconsider the perception of the implementation process of the scheme on the individual farm as based only on economic rationality. By using two continua (production-nature orientation and attachment to agriculture), five different types of landowners are identified: agricultural producers, non-agricultural producers, soft farmers, countryside residents, and amenity residents. By using the typology, it is found that when nature orientation is of increasing importance, planting independently of the subsidy gradually tends to become more likely. This means that not all applicants for the afforestation scheme fit into the pattern of economically rational actors. Instead, the applicants' activities reflect a wide range of practices and values concerning afforestation which we need to acknowledge if we are to fully achieve agri-environmental policies.     

丹麦农业生产中的肥料使用及其对中国的启示

现代农业中大量使用的化肥在提高作物产量的同时,也带来了一些负面影响如土壤肥力下降、土壤板结等。文章综述了丹麦先进的肥料使用和管理方面的经验。丹麦政府通过根据作物需要制定N的允许施用量和P、K的推荐施用量、对肥料的施用季节和施肥方式进行规定、根据土壤检测的结果和作物产量调整营养元素施用量等措施较好地避免了化肥污染问题。这些先进的经验为中国解决化肥污染问题提供了借鉴。笔者提出中国在农业生产过程中应从限制化肥使用量、提高农民知识水平、提倡增施有机肥、改进施肥方式等方面避免对环境的污染。     

Comparison of the Prevalence and Incidence of Infection with Bovine Virus Diarrhoea Virus (BVDV) in Denmark and Michigan and Association with Possible Risk Factors

Based on 2 previous surveys on the occurrence of infection with bovine virus diarrhoea virus (BVDV) in Danish and Michigan dairy herds, the prevalence and incidence of the infection were compared. The presence of certain possible risk factors for the occurrence of infection in the 2 areas were summarized and it was investigated if any of these risk factors had significant effect on the presence of animals persistently infected (PI) with BVDV in the dairy herds. Information on the cattle population density in the 2 areas was obtained from statistical yearbooks. Further information for the individual farms on age distribution, housing of animals, herd size, pasturing and purchasing policy was gathered. The prevalence of PI animals was more than 10 times higher in Denmark as compared to Michigan. In herds without PI animals, the annual incidence of seroconversion as calculated from the age specific prevalence of antibody carriers varied in most age groups between 20–25% in Denmark and between 5–10% in Michigan. All investigated risk factors except for herd size were in favour of a lower prevalence of infection in Michigan. The use of having animals on pasture and at the same time having purchased more than 40 animals within recent 31/2–4 years were significantly associated with presence of PI animals in the dairy herds (p = 0.01) when tested by the Mantel-Haenszel χ². Using mul-tivariable logistic regression, the occurrence of PI animals was found to be significantly related to the study area (Michigan and Denmark) as well as to herd size and purchase intensity.     

Bovine pancreolithiasis in Denmark.

The results of a study of the occurrence of bovine pancreolithiasis in Denmark are given and discussed. Among 65.471 heads of cattle slaughtered at 9 export slaughter-houses during the fourth quarter of 1969, 279 cases were found, giving an average frequency of 0.43%. The frequency among animals below 4 years of age was 0.19%, above 4 years of age 0.82%. A difference in frequency according to breed was demonstrated. It was highest in the Red Danish breed, lower in the Holstein-Friesian breed and lowest in the Jersey breed. Clinical symptoms related to the condition were not found in a retrospective analysis, and correlations with other pathological changes were not apparent. Geographically the cases were uniformly distributed.At 1 export slaughter-house the collection of cases was continued also in the 3 first quarters of 1970. On a 1 year basis comprising 142 cases a higher frequency was found in the late autumn and a lower during the summer.Patho-morphological changes in the affected glands were examined macro- and microscopically. The white, hard, facetted stones were located in the excretory duct system with an accumulation in the main duct, from where a certain expulsion to the duodenum occurs. Secondary inflammatory changes were found in the epithelium and outer layers of the duct system, whereas no significant changes were found in the incretory or excretory components of the gland.The highest absolute and relative weight of the collected and dried stones from each individual case was found in the 3–5 years age group.Chemical analyses showed the main constituent to be calcium carbonate in the modification of calcite, and small amounts of phosphate and magnesium. A comparative chemical analysis on pancreatic stones from cattle in France, England and Denmark did not show any significant differences.     

Towards incorporating spatial risk analysis for Salmonella sero-positivity into the Danish swine surveillance programme

An increased incidence of pork-related human salmonellosis in Denmark led to the development of a national control programme for Salmonella in Danish swine herds in 1993. The aim of the programme has been met and now the issue of cost-effectiveness is receiving greater attention. An appropriate way to address this is to bring a risk-based focus to the programme.

We describe a practical approach to risk-based surveillance through spatial risk assessment using serological and questionnaire data from 2280 herds in 1995. A mixed effects logistic regression model was fitted and both first- and second-order spatial properties of the random effects were investigated. We identified wet-feeding (OR: 0.64; 95% CI: 0.54–0.75) and SPF health status (OR: 0.65; 95% CI: 0.52–0.81) as protective factors for Salmonella sero-positivity. Purchasing feed (OR: 1.81; 95% CI: 1.61–2.04) was a risk factor. The west of the study area generally, and the north of Jutland in particular, experienced the greatest disease risk after controlling for the covariates. There was some evidence for spatial dependency between farms at distances of 6 km (95% CI: 2–35 km) on the Jutland peninsula.

We conclude that when farm location details are analysed in conjunction with routinely recorded surveillance information (such as that collected by the Danish swine Salmonella control programme) and targeted industry surveys (such as those conducted by slaughterhouse co-operatives), our knowledge of the behaviour of disease in animal populations is enhanced and this provides a more informed framework for designing efficient, risk-based surveillance strategies.     

Molecular and morphometric study of metacercariae and adults of Pseudamphistomum truncatum (Opisthorchiidae) from roach (Rutilus rutilus) and wild American mink (Mustela vison)

The presence of metacercariae and adults of the trematode Pseudamphistomum truncatum in roach and mink, respectively, was recorded in Lake Fure North of Copenhagen, Denmark. This zoonotic digenean opisthorchiid represents a threat to humans due to its ability to infect the biliary system following ingestion of inadequately processed infected fish. Therefore precise species identification of infective metacercariae in fish used for human consumption is essential. Due to the relatively limited information on metacercarial identity obtained by morphometric studies a series of molecular techniques were used to link the larval parasite in fish with the un-equivocally diagnosed adults in the biliary system of the mink. By the use of carefully selected polymerase chain reaction (PCR) primers and subsequent sequencing of the ITS region from both metacercariae and adults full sequence identity of both metacercariae and adults were confirmed. The presence of this parasitosis in fish from a lake used for both commercial and recreational fisheries call for hygienic alerts in order to prevent accidental human infection with this opisthorchiid.     

浅析丹麦农业

丹麦创造了可持续发展的环保农业发展模式,从丹麦农业成功经验的基础上看丹麦农业独具特色,文章介绍了丹麦农业的基本情况,特色,农业环保,食品安全,发展方向。通过对丹麦农业发展情况的了解为我国农业发展提供一些参考。     

Nitrate leaching as affected by long-term N fertilization on a coarse sand

Abstract. A field experiment on a coarse sand (1987–92) was conducted with spring barley ( Hordeum vulgare L.), in order to evaluate the effects of increasing N fertilization on nitrate leaching under temperate coastal climate conditions. The N fertilizer levels were 60 and 120 kg N/ha. The experiment was conducted on a 19-year old permanent field trial with continuous spring barley, initiated in 1968, and included treatments with ploughing in autumn or spring, with or without perennial ryegrass ( Lolium perenne L.) as a catch crop undersown in spring. Prior to 1987, the low and high levels of N fertilizer were 70 and 150 kg N/ha, respectively. To calculate nitrate leaching, soil water samples were taken from a depth of 0.8 m using ceramic cups. The average annual nitrate leaching from plots with 60 and 120 kg N/ha was 38 and 52 kg N/ha/y, respectively. The increased leaching associated with increasing fertilizer application was not caused by inorganic N in the soil at harvest, but rather by greater mineralization, mainly in autumn. Growing of a catch crop was relatively more efficient for reducing nitrate leaching than a long-term low fertilizer application. A 50% reduction in N application decreased average yield by 26%, while nitrate leaching decreased by 27%.