Search results for "picea abies"
showing 10 items of 97 documents
Photosynthesis and transpiration of healthy and diseased spruce trees in the course of three vegetation periods
1988
CO2- and H2O-gas exchange of 20- to 25-year-old spruce trees from a plantation in the Hunsruck mountains were investigated over a period of 3 years. All measurements were made as pair comparisons, i.e., in each case the gas exchange of a damaged tree and of a relatively healthy tree in its immediate vicinity was measured simultaneously. A second plantation in the Westerwald mountains consisted of 18-year-old apparently healthy spruce trees. Pair comparison at this location meant comparison of two healthylooking trees. The investigations at both locations included diurnal course measurements of photosynthesis and transpiration, and light saturation curves and CO2-saturation curves of photosy…
Monitoring seasonal changes in microbial populations of spruce forest soil of the Northern Temperate Zone
2012
Soil microbial populations in the Northern Temperate Zone have been poorly studied in comparison with extreme environments. The aim of the work was to study the seasonal changes in the microbial populations of spruce forest soil of the Northern Temperate Zone using classical methods of microbiology and molecular biology. Upper horizons in two Picea abies stands on sod- podzolic and illuvial humus podzol soil were analysed. Sampling was done monthly over a period of twelve months (May 2009-April 2010). Microbial communities in both experimental plots showed different responses to the analysed environmental factors. In the sod-podzolic soil only the fungal DNA amount was significantly higher …
Studies on the Correlation of Putrescine and Potassium Contents in the Needles of Spruce Trees
1995
Summary The correlation between the polyamine putrescine and the nutritional element potassium was examined in Picea abies trees at numerous natural stands in Germany. The amounts of potassium and putrescine in needles was analyzed and a linear negative correlation between the K + and putrescine contents was found, which is significant in the bulk of all stands as well as in subsets. The negative correlation becomes even more pronounced when only sites situated over 600 m with trees older than 60 years are included. While former investigations were concerned with experimental conditions of potassium concentrations in soil or nutrient solutions, the data presented here derive from natural ha…
Investigations on the Polyamine Content of Spruce Needles Relative to the Occurrence of Novel Forest Decline
1991
Summary Levels of free polyamines were monitored in needles of spruce trees [ Picea abies (L.) Karst.] during the course of two vegetation periods at five natural sites. The putrescine concentration in needles of damaged spruce trees was significantly higher than in needles of undamaged trees. This is e.g. impressively proved by the putrescine/spermidine-ratio. While undamaged trees show nearly similar putrescine and spermidine concentrations, damaged trees have five- to tenfold higher putrescine levels depending on the increasing state of damage. Thus, the content of putrescine in needles can be used as a qualified biochemical damage indicator of spruce trees. The physiological effects of …
Phosphoenolpyruvate Carboxylase Activity and Malate Content of Spruce Needles of Healthy and Damaged Trees at Three Mountain Sites
1991
Summary Investigations were carried out on the phosphoenolpyruvate carboxylase (PEPC) activity and the malate content in spruce trees [Picea abies (L.) Karst] at three natural sites. In needles of damaged spruce the PEPC activity is significantly higher than in needles of undamaged spruce. Therefore, the PEPC activity seems to be a biochemical damage indicator in spruce needles. The increase in PEPC activity in damaged trees is discussed as a repair mechanism to compensate the increased need of carbon skeletons by providing oxaloacetate. The malate content is enhanced in needles of severely damaged trees. An increase in malate seems to indicate senescence reactions and may be related to the…
Investigation on phospheonol pyruvate carboxylase and proline in damaged and indamaged needles of Picea Abies and Abies Alba
1998
The client of forest damage is rapidly characterized by visible criteria such as loss and yellowing of leaves and needles Additionally damage to Norway spruce (Picea abies) and silver fit (Abies alba) can be diagnosed by biochemical criteria. The results in the present study performed in 1993 and 1994 on six Norway Spruces of each of the eleven open air stands in south-western Germany indicate that the activity of phosphoenol pyruvate carboxylase (PEPC) correlates with the extent of damage and of the loss of needles, respectively. Needles of severely damaged trees had higher levels of PEPC than needles of healthy trees. There was also a positive correlation between the activity of PEPC and …
Ethylene-biosynthesis in conifers: Investigations on the emission of ethylene and the content of ACC and MACC in Norway Spruce (Picea abies) and silv…
1998
Abstract The assessment of forest damage is carried out throughout the European Community by evaluation of the loss and yellowing of leaves or needles. The results of this ocular damage diagnosis can be confirmed and stated more precisely by applying biochemical criteria, e.g. by monitoring ethylene, its precursor ACC (1-amino-cyclopropane-carboxylate) and the malonyl conjugate of ACC malonyl-amino-cyclopropane-carboxylate (MACC). Therefore we investigated ethylene emissions well as ACC and MACC contents in six Norway Spruce trees (Picea abies) each of eleven permanently monitored sites in the southwest of Germany. The same examinations were applied with silver fir at two additional sites. …
Biochemical indicators for novel forest decline in spruce
1998
Abstract The impact of air pollution on 24 stands of spruce trees in several regions in Germany was investigated. We looked for evidence of biochemical and physiological change at the level of the photosynthetic thylakoid membranes as well as for changes in the antioxidative system in two year old needles. We observed that, as the chlorophyll content decreases in the needles, the amoung of D1 protein declines far more rapidly in relation to the redox components P700 and cytochrome f. Consequently, the PSII/PSI stoichiometry keeps dropping to pregressively lower, meaning unfavorable, values at the chlorophyll content diminishes. This is particularly the case in the higher elevation character…
Selection of biological and chemical parameters indicating or affecting the vitality of Norway spruce
1991
Abstract Thirty-two young and old Norway spruce trees ( Picea abies (L.) Karst.) showing different degrees of damage were investigated in a forest stand in the Taunus Mountains (FRG). The old trees showed visual symptoms of damage such as discolouration of the needles and needle loss. Over 70 biometric, physiological and chemical parameters were determined for needle and soil samples. Interrelationships between these variables were described by correlation analysis. The most discriminant variables between different groups of trees were found by Fisher weighing. This reduced data set was used for principal component analysis and for the classification of various parameters according to diffe…
Organic material dissolved during oxygen-alkali pulping of hot-water-extracted spruce sawdust
2016
Untreated and hot-water-extracted (HWE) Norway spruce (Picea abies) sawdust was cooked using the sulfur-free oxygen-alkali (OA) method under the following conditions: temperature, 170 °C; liquor-to-wood ratio, 5:1 L/kg; and NaOH charge, 19% on the oven-dry sawdust. In comparison with earlier studies conducted with birch sawdust, the spruce cooking yield data, together with the amount of the pulp rejects (78% to 86% for reference pulps from the initial feedstock and 73% to 83% for pulps from the HWE feedstock), revealed that the pretreatment stage prior to spruce OA pulping caused different effects on pulping performance. The analyses of the three main compound groups (i.e., lignin, volatile…