Within- and between-stand distribution of attacks by pine weevil [Hylobius abietis (L.)]

The pine weevil (Hylobius abietis L.) is considered one of the most damaging pests in reforestation areas in Scandinavia. The purpose of this study was to ascertain the within- and between-stand distribution of pine weevil attacks. Between-stand distribution was examined by assessing the frequency of attacks in all newly planted coniferous stands in relation to stands clear-cut at two state forest districts in North Zealand, Denmark. Within-stand distribution was examined by investigating the position and damage to individual seedlings in relation to the position of breeding material. The stand-level attack frequency did not seem to be higher for stands in areas with more clear-cuts. The within-stand distribution of attacks was not influenced by the position of breeding material.     

Long continued applications of N fertilizer to cereals on sandy loam: grain and straw response to residual N

Abstract. The residual value of mineral N fertilizer applied in the spring was investigated in a field experiment where four cereals (winter wheat, winter barley, spring barley and spring oats) had been grown at reduced (0.7N), normal (1N) or high (1.3N) N fertilizer rates for 20 to 28 years. The effect of previous N fertilizer dressing was tested in two succeeding years by replacing the original N rate with five test N rates ranging from 0 to 240 kg N ha^?1 for winter cereals and 0 to 200 kg N ha^?1 for spring cereals. In the first test year, winter wheat grown on plots previously supplied with the high rate of mineral fertilizer (202 kg N ha^?1 yr^?1) yielded more grain and straw and had a higher total N uptake than wheat on plots previously supplied with the normal (174 kg N ha^?1 yr^?1) or reduced (124 kg N ha^?1 yr^?1) rate. The grain yield response and N uptake was not significantly affected by the N supply in the test year. The winter wheat grown in the second test year was unaffected by the previous N supply. Grain and straw yield response and total N uptake for spring barley, winter barley and oats, were almost identical irrespective of the previous N rate. After 20 to 28 years there were no significant differences in soil C and N (0 to 20 cm) between soil receiving three rates of N fertilizer. Soil from differently fertilized oat plots showed no significant differences in N mineralizing capacity. Nitrate leaching losses from the soils at the three N rates were estimated and the N balances for the 20 to 28 years experimental period calculated. The data indicated a reduction in overall loss of 189 to 466 kg N ha^?1 at the normal and high N rates compared with the reduced N rate. We conclude that the N supplying capacity and soil organic matter content of this fertile sandy loam soil under continuous cereal cropping with straw removal was not significantly affected by differences in N fertilizer residues.     

Lungworm infections (Angiostrongylus vasorum, Crenosoma vulpis, Aelurostrongylus abstrusus) in dogs and cats in Germany and Denmark in 2003–2007

Faecal samples of 4151 dogs from Denmark, 958 dogs from Germany and 231 cats from Germany with clinical signs were examined for lungworm larvae using the Baermann funnel technique between 2003 and 2007. In total, 3.6% of Danish and German dogs shed lungworm larvae. In Denmark, patent infections of dogs with Angiostrongylus vasorum were more prevalent (2.2%) than those with Crenosoma vulpis (1.4%). In Denmark, the majority of A. vasorum- (98%) and C. vulpis-infected (80%) dogs originated from Northern Zealand. The frequency of A. vasorum and C. vulpis infections in Danish dogs obviously decreased from 2003 to 2006. In Germany, canine faecal samples were found more frequently positive for C. vulpis than for A. vasorum larvae (2.4% and 1.2%, respectively). Lungworm-infected dogs originated mainly from southern and western Germany. Larvae of Aelurostrongylus abstrusus were detected in 5.6% of cats from Germany. Overall, a distinct seasonal pattern in the detection of infected dogs was apparent for A. vasorum in Denmark and C. vulpis in Germany. The relatively high number of lungworm-infected dogs and cats indicate that these parasitic diseases should be considered in differential diagnosis of cases of treatment-resistant respiratory/cardiopulmonary distress.     

Quantitative assessment of the likelihood of the introduction of classical swine fever virus into the Danish swine population

Classical swine fever virus (CSFV) is a major infectious-disease agent of livestock and causes production losses through increased morbidity and mortality, particularly of young pigs. We identified the pathways for introduction of CSFV into Denmark and assessed the annual probability of introduction (based on a US Department of Agriculture model). We developed pathways based on material from scientific articles, reports from veterinary agencies and custom officers, and consultations with experts in the field. Returning livestock trucks and legal meat imports were the most important pathways for CSFV introduction to Denmark from other EU states with predicted overall likelihood of one or more introductions of CSFV within a median of 130 years (46-280) provided mitigating steps, such as cleaning trucks, were maintained to a very high standard. The likelihood would increase dramatically if these activities were abandoned: one or more introductions within a median of 5.2 years (2-14). The predicted risks from live-animal imports and semen were extremely low given the very few imports of these products. The most important countries for Denmark's CSFV risk are Germany and the Netherlands, though this risk is again predicted to be dramatically reduced as long as mitigating activities are maintained. We predicted the risk from illegal movements of pork into Denmark to be low because little pork enters through this route and only a small fraction of this pork would be fed to pigs.     

丹麦森林医疗花园——以纳卡蒂亚森林医疗花园为例

自20世纪80年代以来,医疗花园在世界各地蓬勃发展。森林以其独特的环境,经过适当的设计,是理想的天然医疗花园。文中概述了丹麦森林和森林医疗花园发展情况,详细介绍了丹麦纳卡蒂亚森林医疗花园,包括设计理念及方案和医疗活动安排等,以期对我国森林医疗花园的兴起和发展起到推动作用。     

丹麦畜禽粪肥利用对中国种养结合循环农业发展的启示

丹麦在畜禽养殖粪肥利用方面处于世界领先地位。丹麦完善的粪肥利用体系可做到种养平衡和按需施肥,在保证畜牧业健康发展的同时,也促进了种植业的发展。该文综述了丹麦粪肥利用与管理现状,重点分析了丹麦种养平衡生产模式和粪肥施用过程中氨减排技术,从科学理念、法规体系、先进技术和成熟模式等方面总结了丹麦畜禽养殖粪肥利用的成功经验,包括全过程污染控制的科学理念,详细量化、严格执行的管理政策法规,先进的粪肥利用关键技术装备,以及完善的粪肥利用模式,以期提高中国畜禽养殖粪肥利用水平,为推进中国种养循环农业发展提供借鉴。     

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%.     

Automatic Stem Mapping in Three Dimensions by Template Matching from Aerial Photographs

Recent developments in remote sensing have shown promising results for the detection and species classification of individual trees from high-resolution imagery of forests in leaf-on condition. Existing image-analysis algorithms produce a two-dimensional stem map in the observed imagery. This paper develops a new algorithm that generalizes existing template-matching algorithms to produce a stem map in the three dimensions of a forest in leaf-off condition. A self-contained algorithm to produce artificial template images is introduced. The image-analysis algorithm was applied to oak ( Quercus robur L.) grown under standard silvicultural treatment in Denmark. One analysis gave detection rates in the range 85-98% and root mean squared errors on the stem base coordinates below 8.1, 7.6 and 20.5 cm in the x -, y - and z -directions, respectively. It is concluded that it is indeed feasible to produce a quite accurate three-dimensional stem map.     

Rodent impact on establishment of direct-seeded Fagus sylvatica,Quercus robur and Quercus petraea on forest land

Abstract

Seed predation by granivorous rodents constitutes a major problem during reforestation using direct seeding. Acorns or beech nuts were sown at 14 different sites in Denmark and southern Sweden, and seedling establishment was inventoried during the first three growing seasons. Around the time of sowing, rodents were either snap-trapped or live-trapped. At some sites, perches for raptors were installed, and at other sites, signs of predation were investigated or predation was monitored by camera surveillance. Granivorous rodents had a profound negative influence on sowings, and the removal of beech nuts occurred rapidly following sowing. Establishment of oak was better when surroundings consisted of mixed forests rather than broadleaved forests. Fewer rodents were caught, and establishment was better, in large reforestation areas. Rodent captures indicated that forest edges, slash piles and stone wall remains were suitable rodent microhabitats. Snap-trapping or raptor perches did not result in increased oak establishment. Neither sowing in summer nor increased seeding depth decreased predation by rodents on beech nuts. In conclusion, seeds need protection from rodents immediately at the time of sowing. Choosing large regeneration areas combined with removal of suitable rodent habitats seems to be a practical alternative for the development of successful strategies for direct seeding.     

An epidemiologic study of late-term abortions in dairy cattle in Denmark, July 2000-August 2003

Abortion in dairy cows in well-managed dairies is not common but differences have been reported probably due to variation in animal health, nutrition and management, as well as difficulties in observing the aborted material. A 38-month study of 507 large Danish dairy herds revealed 3354 late-term abortions and 224,419 calvings were recorded. During the study period, a total of 3717 submissions were made to the Danish Institute for Food and Veterinary Research (DFVF). A broad spectrum of abortive agents was isolated but none were found to be statistically associated with abortions. The number of abortions in a month on a dairy was significantly (P<0.001) associated with the number of cows in the third trimester but explained only 11% (R(adj)(2)=0.114) of the variability of the reported abortions. A total of 23 herds (4.5%) reported 531 abortions (15.8%). Although a marginally significant (P=0.11) risk of increased abortions was found to exist in bovine viral diarrhea virus- (BVDV) infected herds, it could be at least partially explained by additional calvings in those herds. Temporal correlation between inseminations and abortions was statistically significant (P<0.001) with the highest correlation (r=0.47-0.51) after lagging abortions on insemination by 6-8 months. No indication of spatial clustering was detected for either specific-abortogenic pathogens or high aborting dairies using either Cuzick-Edwards' (P>0.17) or spatial scan tests (P>0.23). Ederer-Myers-Mantel test was applied to 3 years of data on the highest aborting dairies and showed that July had nearly double the expected number of maximum monthly abortions (P<0.001). These findings provide further insight into the reported abortion pattern in Danish dairies and may facilitate planning future control programs.