The Influence of Carbon Dioxide or Ozone Concentration on Growth and Assimilate Partitioning in Seedlings of Nine Conifers     

Leiv M. Mortensen 《Acta Agriculturae Scandinavica, Section B - Plant Soil Science》2013,63(3):157-163

Abstract

Seedlings of nine different conifers were exposed to 355 and 730 μmol mol-1 CO₂, or low (> 15 nmol mol^?1) and elevated 0₃ concentration (70 nmol mol^?1) for 81–116 days. The experiments were conducted in growth chambers placed in a greenhouse. Increased CO₂ concentration enhanced the mean relative growth rate (RGR) and total plant dry weight by 4 and 33% in Larix leptolepis, by 4 and 38% in Larix sibirica, by 7 and 47% in Picea glauca and by 3 and 16% in Picea sitchensis, respectively. The growth rates and dry weights of Pimis contorta, Pinus mugo and Pseudotsuga menziesii were not significantly affected. Carbon dioxide enrichment enhanced RGR of two provenances of Picea abies by 4 and 6%, respectively, while a third provenance was unaffected. In Pimis sylvestris, only the RGR of one of three provenances was stimulated by CO₂ enrichment (4%).

After two growth seasons CO₂ enrichment enhanced RGR and total plant dry weight by 11 and 35% in Picea abies and by 12 and 36% in Pinus sylvestris, respectively. Elevated CO₂ decreased the shoot:root ratio in Larix leptolepis, and decreased the needlerstem ratio in Picea glauca, but increased it in Pseudotsuga menziesii.

Elevated O₃ significantly decreased the plant dry weight in Picea sitchensis, Pseudotsuga menziesii and in one of three provenances of Pinus sylvestris, while the other species and provenances were unaffected. Increased O₃ concentration increased the shoot:root dry weight ratio in one of three Picea abies provenances, in all three Pinus sylvestris provenances and in Pinus contorta. The needle:stem ratio was enhanced by O₃ in seven of the nine species. The O₃ exposure caused chlorosis of needles in all species except Pseudotsuga menziesii.  相似文献   

Dietary calcium-phosphorus ratios for growing pigs in relation to serum levels and bone development     

N C Nielsen  S Andersen  A Madsen  H P Mortensen 《Acta veterinaria Scandinavica》1971,12(2):202-219

Two experiments comprising a total of 80 Danish Landrace pigs in the period 20–90 kg live-weight were carried out to study the effect of dietary levels and ratios of Ca and P on serum values of Ca, inorg. P, and alkaline phosphatase and on the development of degenerative arthritis and atrophic rhinitis.In both experiments each kg feed (Table 1) was supplemented with 600 i. u. vitamin D₃ and 80 p. p. m. Zn.In the first experiment the Ca:P ratio was 1.2 and the amount of Ca increased from 0.48 % to 1.20 % without influencing daily gain, feed conversion, carcass performance (Table 2) or frequency of atrophic rhinitis (Table 3). The Ca:P ratio in scapula was 2.15. Only when the diet was supplemented with 1.20 % Ga and 1.00 % P the bone quality was histomorphologically adequate (Figs. 1–4).In the second experiment various Ca:P ratios (ranging from 0.1 to 3.0) were compared with the recommended level and ratio of 0.72 % Ga and 0.60 % P. Performance of pigs on the normal level was better than for the other pigs (Table 4). Clinically, various degrees of leg-weakness and -deformation occurred, most pronounced in the high Ca — low P group. Very little lameness and no convulsions were observed. Marked hypocalcemia was not found. Unilateral high Ca intake increased serum Ca significantly, and serum alkaline phosphatase slightly, and decreased serum P (Figs. 5–7). Advanced pericytic osteolysis, poor mineralization and generalized osteodystrophia fibrosa were found in the low Ca groups (Figs. 8–13). The groups showed no differences in frequency of atrophic rhinitis (Table 5), and rickets was not observed.The incidence of degenerative joint lesions was not increased in pigs on the unfavourable Ca:P ratios, and depended apparently more on litters than on diets.  相似文献   

Ecological effects of climate fluctuations   总被引：3，自引：0，他引：3  

Stenseth NC  Mysterud A  Ottersen G  Hurrell JW  Chan KS  Lima M 《Science (New York, N.Y.)》2002,297(5585):1292-1296

Climate influences a variety of ecological processes. These effects operate through local weather parameters such as temperature, wind, rain, snow, and ocean currents, as well as interactions among these. In the temperate zone, local variations in weather are often coupled over large geographic areas through the transient behavior of atmospheric planetary-scale waves. These variations drive temporally and spatially averaged exchanges of heat, momentum, and water vapor that ultimately determine growth, recruitment, and migration patterns. Recently, there have been several studies of the impact of large-scale climatic forcing on ecological systems. We review how two of the best-known climate phenomena-the North Atlantic Oscillation and the El Ni?o-Southern Oscillation-affect ecological patterns and processes in both marine and terrestrial systems.  相似文献   

Exercising the Pregnant Mare from Day 16 to Day 80 of Gestation     

Jason E. Anton  Kristine L. Vernon  Dale E. Kelley  John R. Gibbons  Glen Birrenkott  Chris J. Mortensen 《Journal of Equine Veterinary Science》2014

Our previous research has demonstrated moderate exercise can be detrimental to early pregnancy in the mare, but little work has examined exercise after pregnancy has been detected. We exercised mares (n = 8) 6 days a week for 45 min from Day 16 until Day 80 of gestation. Color Doppler ultrasonography was used to evaluate embryonic vesicle size, fetal length, and uterine blood flow. Blood was sampled every other day to analyze cortisol and progesterone concentrations. Results indicated that exercising pregnant mares (n = 4) led to greater (P < .01) cortisol concentrations 30 min after the exercise period. No overall treatment effect could be detected in progesterone concentrations; however, following Day 60 of gestation, progesterone concentrations were lower (P < .05) in exercised mares. Additionally, progesterone concentrations peaked earlier in exercised mares at Day 52 of gestation compared to peak levels at Day 68 of gestation for control mares. No significant effects were detected in embryonic vesicle size. Fetal length tended (P = .06) to be longer in the conceptus of exercised mares. Uterine blood flow did not differ between groups but increased as pregnancy progressed (P < .001) in both groups. All mares in this study went on to deliver healthy foals and suffered no difficulties during parturition. These results indicated that moderate exercise was not detrimental to mare pregnancy.  相似文献   

Patterns of Tetracapsuloides bryosalmonae infection of three salmonid species in large,deep Norwegian lakes     

Tone Jran Oredalen  Mona Sb  Tor Atle Mo 《Journal of fish diseases》2022,45(1):185-202

Proliferative kidney disease (PKD), caused by the myxozoan endoparasite Tetracapsuloides bryosalmonae, is of serious ecological and economical concern to wild and farmed salmonids. Wild salmonid populations have declined due to PKD, primarily in rivers, in Europe and North America. Deep lakes are also important habitats for salmonids, and this work aimed to investigate parasite presence in five deep Norwegian lakes. Kidney samples from three salmonid species from deep lakes were collected and tested using real-time PCR to detect PKD parasite presence. We present the first detection of T. bryosalmonae in European whitefish in Norway for the first time, as well as the first published documentation of the parasite in kidneys of Arctic charr, brown trout and whitefish in four lakes. The observed prevalence of the parasite was higher in populations of brown trout than of Arctic charr and whitefish. The parasite was detected in farmed, but not in wild, charr in one lake. This suggests a possible link with a depth of fish habitat and fewer T. bryosalmonae-infected and PKD-affected fish. Towards a warmer climate, cold hypolimnion in deep lakes may act as a refuge for wild salmonids, while cold deep water may be used to control PKD in farmed salmonids.  相似文献   

Foliar Injuries Caused by Ozone in Betula pubescens Ehrh. and Phleum pratense L. as Influenced by Climatic Conditions Before and During O3 Exposure     

Leiv M. Mortensen 《Acta Agriculturae Scandinavica, Section B - Plant Soil Science》2013,63(1):44-49

Seedlings of Betula pubescens Ehrh. (mountain birch) and Phleum pratense L. (timothy) were grown for 42 days under full light or 50% shade in the field at 12°C, and at comparable photosynthetic active radiation (PAR) levels in a greenhouse at 18°C. Plants from the four pretreatments were exposed to 78 nmol mol^-1 (ppb) O₃ (8 h day^-1) under two temperatures (15 and 25°C), two relative air humidities (50 and 80% RH) or two CO₂  相似文献   

Evidence of long distance airborne transmission of Aujeszky's disease (pseudorabies) virus   总被引：4，自引：0，他引：4  

L S Christensen  J Mousing  S Mortensen  K J Soerensen  S B Strandbygaard  C A Henriksen  J B Andersen 《The Veterinary record》1990,127(19):471-474

Aujeszky's disease has been the subject of an eradication campaign in Denmark since 1980. A detailed knowledge of the virus strains present in the country was provided by restriction fragment analyses of older clinical isolates, and of isolates from all the virologically confirmed outbreaks since 1985. The introduction of foreign strains into southern border areas was demonstrated during the winters of 1984/85, 1986/87 and 1987/88. An epizootic during the winter of 1987/88 was shown to correlate with an unusual predominance of southerly winds. Both conventional and specific pathogen free herds became infected. A herd level case-control analysis of the outbreaks during the winter of 1987/88 revealed that there was a positive correlation between the risk of infection and the size of the herd. The observations support the hypothesis of airborne transmission of the disease.  相似文献   

Effects on nutrients and on grain quality in spring wheat crops grown under elevated CO₂ concentrations and stress conditions in the European, multiple-site experiment ‘ESPACE-wheat’     

A. Fangmeier  L. De Temmerman  L. Mortensen  K. Kemp  J. Burke  R. Mitchell  M. van Oijen  H. -J. Weigel 《European Journal of Agronomy》1999,10(3-4):215-229

Nutrient element concentrations and grain quality were assessed in spring wheat grown under elevated CO₂ concentrations and contrasting levels of tropospheric ozone at different nitrogen supply rates at several European sites. Carbon dioxide enrichment proved to affect nutrient concentrations in a complex manner. In green leaves, all elements (with exception of phosphorus and iron) decreased. In contrast, effects on the element composition of grains were restricted to reductions in nitrogen, calcium, sulphur and iron. Ozone exposure resulted in no significant effects on nutrient element concentrations in different tissues in the overall analysis. The nitrogen demand of green tissues was reduced due to CO₂ enrichment as shown by reductions in the critical leaf nitrogen concentration and also enhanced nitrogen use efficiency. Reductions in the content of ribulose-bisphosphate carboxylase/oxygenase and repression of the photorespiratory pathway and reduced nitrogen allocation to enzymes driving the photosynthetic carbon oxidation cycle were chiefly responsible for this effect. Thus, nitrogen acquisition by the crop did not match carbon acquisition under CO₂ enrichment. Since crop nitrogen uptake from the soil was already completed at anthesis, nitrogen allocated to the grain after anthesis originated from vegetative pools—causing grain nitrogen concentrations to decrease under CO₂ enrichment (on average by 15% when CO₂ concentrations increased from 360 to 680 μmol mol⁻¹). Correspondingly, grain quality was reduced by CO₂ enrichment. The Zeleny value, Hagberg value and dry/wet gluten content decreased significantly with increasing [CO₂]. Despite the beneficial impact of CO₂ enrichment on growth and yield of C₃ cereal crops, declines in flour quality due to reduced nitrogen content are likely in a future, [CO₂]-rich world.  相似文献   

Forms and plant-availability of sulfur in cattle and pig slurry     

Jrgen Eriksen  Jrgen V. Mortensen  Viggo K. Kjellerup  Ole Kristjansen 《植物养料与土壤学杂志》1995,158(1):113-116

The contribution of animal slurry to the supply of S to plants was studied. The total-S content of cattle and pig slurry was significantly correlated to DM and nitrogen content and was composed of sulfide, sulfate and C-bonded S. During 42 weeks of storage sulfate concentrations decreased and sulfide and C-bonded S concentrations increased. In a pot experiment plant-availability of S in slurry was found to be low, 5 to 7% of total-S.  相似文献   

National character does not reflect mean personality trait levels in 49 cultures     

Terracciano A  Abdel-Khalek AM  Adám N  Adamovová L  Ahn CK  Ahn HN  Alansari BM  Alcalay L  Allik J  Angleitner A  Avia MD  Ayearst LE  Barbaranelli C  Beer A  Borg-Cunen MA  Bratko D  Brunner-Sciarra M  Budzinski L  Camart N  Dahourou D  De Fruyt F  de Lima MP  del Pilar GE  Diener E  Falzon R  Fernando K  Ficková E  Fischer R  Flores-Mendoza C  Ghayur MA  Gülgöz S  Hagberg B  Halberstadt J  Halim MS  Hrebícková M  Humrichouse J  Jensen HH  Jocic DD  Jónsson FH  Khoury B  Klinkosz W  Knezević G  Lauri MA  Leibovich N  Martin TA 《Science (New York, N.Y.)》2005,310(5745):96-100

Most people hold beliefs about personality characteristics typical of members of their own and others' cultures. These perceptions of national character may be generalizations from personal experience, stereotypes with a "kernel of truth," or inaccurate stereotypes. We obtained national character ratings of 3989 people from 49 cultures and compared them with the average personality scores of culture members assessed by observer ratings and self-reports. National character ratings were reliable but did not converge with assessed traits. Perceptions of national character thus appear to be unfounded stereotypes that may serve the function of maintaining a national identity.  相似文献