Nutrient balance in Scots pine (Pinus sylvestris L.) forest. 5. Tree growth in a field plot experiment

A field plot experiment on fertilization with N, Mg and P in Scots pine forest was established. The experiment had a factorial design with three levels of N (0, 30 and 90 kg ha^?1), two levels of Mg (0 and 1.5 kg ha^?1) and two levels of P (0 and 5.3 kg ha^?1). The application was done annually. There was a significant growth increase for the two N treatments. During a period of 5-years the mean increase in volume increment was 2.3 and 4.5 m³ ha^?1 for the 30 N and 90 N kg ha^?1 yr^?1 treatments, respectively. This represents a percentage increase in volume increment of 53 and 102% compared to the untreated control plots. No significant growth effect of P and Mg application was detected, either alone or in combination with N. The needle nutrient concentrations have been followed along with the annual measurements. An increase in N-concentration was detected after the first growing season in the N treated trees. After five years the Mg concentrations in the needles are lower in these treatments. The one year old needles have concentrations as low as 0.05% Mg. No visible deficiency symptoms have been observed. The field experiment effects demonstrates that N is still the most limiting nutrient under these conditions and that there is a relative large potential for N accumulation in these forest types without negative effects.     

Acidification and Liming of River Vikedal, Western Norway. A 20 Year Study of Responses in the Benthic Invertebrate Fauna

This paper deals with benthic invertebrate population responses to acidification and liming in the lower part of River Vikedal. In 1979 the river showed signs of increasing acidification. Highly sensitive invertebrates like the mayfly Baetis rhodani were present in the river in low abundance, but disappeared in the subsequent years. In order to re-establish a non-toxic water quality for fish, liming of the spring snowmelt to a minimum of pH 5.7 was started in 1987. During the later years liming has been successively increased. The invertebrate fauna showed a slow, but positive, response during the first years after liming, especially during autumn. B. rhodani recolonized the river in low density, but the spring cohort was still weak. Since 1994 the lime dosage was increased to secure a minimum pH of 6.3 during spring snowmelt. This has resulted in an overall increased biodiversity in the limed section of the river. Several acid-sensitive species, like both cohorts of B. rhodani and freshwater snails have colonized this part of the river. Simultaneously biodiversity in the unlimed reference sites has slightly improved during the last years. This is correlated with decreased sulphur deposition and improved surface water chemical conditions.     

Impacts of acid precipitation on coniferous forest ecosystems

This paper summarizes the results from current studies in Norway. One main approach is the application of artificial acid ‘rain’ and of lime to field plots and lysimeters. Application during two growth seasons of 50 mm mo^?1 of ‘rain water’ of pH 3 to a podzol soil increased the acidity of the humus and decreased the base saturation. The reduction in base saturation was mainly due to leaching of Ca and Mg. Laboratory experiments revealed that decomposition of pine needles was not affected by any acid ‘rain’ treatment of the field plots. Liming slightly retarded the decomposition. No nitrification occurred in unlimed soils (pH 4.4-4.1). Liming increased nitrification. The soil enchytraeid (Ohgochaeta) fauna was not much affected by the acidification. Germination of spruce seeds in acidified mineral soil was negatively affected when soil pH was 4.0 or lower. Seedling establishment was even more sensitive to increasing soil acidity. Analysis of throughfall and stemflow water in southernmost Norway reveals that the total deposition of H₂SO₄ beneath spruce and pine is approximately two times the deposition in open terrain. A large part of this increase is probably due to dry deposition. Increased acidity of the rain seems to increase the leaching of cations from the tree crowns. Tree-ring analysis of spruce (Picea abies (L.) Karst.) and pine (Pinus sylvestris L.) has been based on comparisons between regions differently stressed by acid precipitation and also between sites presumed to differ in sensitivity to acidification. No effect that can be related to acid precipitation has yet been detected on diameter growth.     

A radiological study on the development of vertebral deformities in cultured Atlantic salmon (Salmo salar L.)

This study investigated the development of skeletal deformities in individually tagged Atlantic salmon (n = 805) from the parr stage (Sept 2001, 70 g mean ± 34 g S.D.) until 10 month after transfer to seawater (Feb 2003, 3040 g mean ± 1097 g S.D.). A subgroup of the total population (n = 129) was radiographed as parr (Feb 2002) and again 10 months after transfer to seawater (Feb 2003). Eight percent of the males matured sexually during their first autumn in sea (jack), and were excluded from further analysis. Based on an external examination of each fish (n = 773), 1.8% (n = 14) developed skeletal deformities (0.1% operculum deformities (n = 1), 0.4% jaw deformities (n = 3), 1.3% vertebral deformities (n = 10)) during the experiment. Based on evaluation of radiographs (n = 129), the prevalence of vertebral deformities was 7.0% (n = 9) at the parr stage, and 12.4% (n = 16) 10 months after transfer to seawater. From radiographs, longitudinally compressed vertebral bodies without intervertebral spaces were classified as ankylosis and compression, longitudinally compressed vertebral bodies with intervertebral spaces were classified as compressions, and dislocated vertebral bodies with a normal morphology and without intervertebral spaces were classified as ankylosis and dislocation. Of the fish that developed deformities during the experiment, 8 had ankylosis and compressions, 7 had compressions and 1 had ankylosis and dislocation. Ankylosis and compression developed in the region between vertebrae number 1 and 16, whereas compressions developed in the region between vertebrae number 13 and 49. Most of the individuals with compression 10 months after transfer to seawater had normal vertebral columns as parr, whereas all individuals with compression and ankylosis 10 months after transfer to seawater had deformed vertebral columns as parr.     

Some chemical and biological properties of a protein concentrate from nigerseed (Guizotia abyssinica Cass.)

A protein concentrate has been prepared from nigerseed (Guizotia abyssinica Cass.) by a method involving extraction of the protein with NaCl-solution.The protein concentrate contains about 65% of protein (N×5.5) calculated from the dry weight, and the amino acid pattern is fairly well balanced. The chemical score is 82 calculated from the A/E values.The nutritional value of the product has been tested on young rats. These tests revealed the presence of antinutritional factors in the protein concentrate. The PER was only 1.5.It was also found that the rate of digestion by pancreatin was much slower for the protein concentrate than for casein, possibly due to enzyme resistent linkages.The protein concentrate seems to be devoid of hemagglutinin activity. Antibodies against the nug extracts could not be found.

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Zusammenfassung Ein Proteinkonzentrat wurde aus Nug-Samen (Guizotia abyssinica Cass.) durch eine Methode gewonnen, die eine Extraktion des Proteins mit NaCl-Lösung einschließt.Das Proteinkonzentrat enthalt etwa 65% Protein (N x 5,5), berechnet auf das Trockengewicht. Das Aminosäuregleichgewicht ist relativ gut balanziert. Die chemical score nach den A/E Werten berechnet, beträgt 82.Der Nährwert des Produktes ist an jungen Ratten getestet worden. Diese Tests zeigten das Vorhandensein von Antinähr-Faktoren im Proteinkonzentrat. Die PER (protein efficiency ratio) betrug nur 1,5.Es wurde außerdem festgestellt, daß die Geschwindigkeit der enzymatischen Verdauung (mit Pankreatin) für das Proteinkonzentrat viel langsamer abläuft als für Casein. Dieses ist vielleicht bedingt durch Enzymresistente Bindungen.Das Proteinkonzentrat scheint von Hämagglutininaktivität frei zu sein. Es wurden keine Antikörper gegen Nug-Extrakte gefunden.

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Résumé Une solution concentrée de protéine a été préparée de grains de nug (Guizotia abyssinica Cass.) par une méthode contenant l'extraction de la protéine avec la solution NaCl.La solution concentrée contient environ 65% de protéine (N X 5,5) calculée du poids sec, et le modèle des aminoacides est assez bien balancé. Le chemical score est 82 calculé des valeurs A/E. La valeur nutritive du produit a été éprouvé à de jeunes rats. Ces épreuves ont révélé la présence d'éléments antinutritives dans la solution concentrée de protéine. La PER (protein efficiency ratio) était seulement 1,5.On a aussi trouvé que la rapidité de digestion enzymatique (avec la pancréatine) pour la solution concentrée de protéine était beaucoup plus lente que pour le casein. Ceci est peut-être du à des liaisons qui résistent aux enzymes.Il semble que la solution concentrée de protéine manque d'activité hemagglutinine. On n'a pas pu trouver des anticorps dirigés contre les extraits de nug.

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CNU Report No. 34.     

Effects of inoculum size on cell-mediated and humoral immune responses of foals experimentally infected with Rhodococcus equi: A pilot study

The objective of this pilot study was to compare the cytokine profile as well as cell-mediated and antibody responses of foals infected with a low inoculum of virulent Rhodococcus equi resulting in subclinical pneumonia to that of foals infected with a high inoculum resulting in severe clinical pneumonia. The mean (±SD) ratio of post-infection to pre-infection anti-R. equi IgG(T) concentration was significantly (P = 0.002) higher in foals infected with the high inoculum (195 ± 145; range 62–328) compared to foals infected with the low inoculum (3.9 ± 4.5; range 0.5–11). Similarly, mean (±SD) ratio of post-infection to pre-infection IgM concentration was significantly (P = 0.002) higher in foals infected with the high inoculum (12 ± 4.0; range 7.4–14) compared to foals infected with the low inoculum (2.5 ± 1.5; range 1.2–4.7). Proliferative responses to R. equi antigens as well as expression of mRNA for IL-2, IL-4, IL-10, and IFN-γ in BLN were not significantly different between the two groups. There was a tendency (P = 0.073) towards a higher IFN-γ/IL-4 ratio in the low inoculum group. This study demonstrates that the size of inoculum modulates the IgG subisotype response and possibly the cytokine profile of foals.