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1.
《Forest Ecology and Management》1999,114(1):55-70
Litterfall was investigated in three even-aged Norway spruce (Picea abies), sitka spruce (Picea sitchensis) and beech (Fagus sylvatica) stands on a nutrient poor-soil in Southern Denmark. Dry weights and N, P, K, S, Mg, Ca, Na, Al, and Fe concentrations and fluxes were examined in litterfall fractions. Foliage litter amounted to 90% of total litterfall. The tree stands showed a similar mean annual litterfall. In the spruce stands, annual litterfall was correlated negatively with the current year increment and positively with the previous year increment. Annual litterfall in beech was constant during the 6 study years whereas Norway spruce and sitka spruce showed large fluctuations between years caused by drought, spruce aphid infestations and probably sea salt stress. Norway spruce responded with a long lasting elevated needle loss. Sitka spruce responded to infestations with premature needle loss during short periods. The presence of a large syrphid (Coccinellidae) population was important in regulating aphid (Elatobium abietinum) population density. The between-year variation in element concentrations of litterfall was small whereas variations during the year were large. Interspecific levels were recognized: Norway spruce>beech>sitka spruce. High concentrations in Norway spruce were ascribed to a combination of drought, sea salt stress and elevated transpiration. In sitka spruce, aphid infestations reduced the litterfall N content. Sitka spruce showed the smallest amount of base cation fluxes with litterfall. In contrast, spruce and beech exhibited even litterfall element fluxes. Litterfall studies revealed reduced vitality in the non-native spruce stands and underlined the perception of a healthy stand of native beech. 相似文献
2.
Crystallinity of wood and the size of cellulose crystallites in Norway spruce (<Emphasis Type="Italic">Picea abies</Emphasis>) 总被引：5，自引：0，他引：5
X-ray diffraction was used to study variations in the crystallinity of wood and the average thickness and length of the crystallites of cellulose as a function of the number of the year ring in Norway spruce [Picea abies (L.) Karst.]. The crystallinity increased from ring 4 to ring 10 from the pith and was constant after ring 10. The crystallinity of mature wood was about 30% ± 5%. The average thickness and average length of the crystallites were 3.2 ± 0.1nm and 28 ± 2nm, respectively; and no systematic variation of these values with the number of the year ring was observed. The mean microfibril angle decreased near the pith but was constant in the mature wood. 相似文献
3.
《Scandinavian Journal of Forest Research》2012,27(1-4):177-193
Temporal variation in nutrient concentrations of Scots pine (Pinus sylvestris L.) needles was studied during a three‐year period in three stands of differing stages of development. Concentrations of N, P and K varied significantly between years; this variation was related to differences in needle dry weight. Concentrations of all measured nutrients (N, P, K, Ca, Mg, Mn, Cu, Zn, Fe, B) and Al varied between seasons; this variation was related to nutrient mobility and the annual physiological cycle. Concentrations of the mobile nutrients N, P and K decreased in spring and early summer during shoot and needle elongation and increased in late summer and autumn during needle senescence and litterfall. Concentrations of Mg, Cu, Zn and B followed somewhat similar patterns. The poorly mobile nutrients Ca, Mn and Fe accumulated gradually in needles during each growing season. Needle nutrient concentrations were stable during the nonactive period. 相似文献
4.
I. D. Cave 《Wood Science and Technology》1997,31(3):143-152
Summary The property of fibre symmetry as exhibited by wood cellulose can be used to derive an explicit relationship between the orientation of a cellulose microfibril and the orientation of the X-ray beam diffracted by any of its crystallographic planes. The solution applies to a microfibril of any orientation and so is well suited to evaluating the microfibril angle distribution in wood containing cells of any cross-sectional shape. The (002) and (040) reflections of cellulose have complementary properties that could be exploited to enable current problems associated with the use of each individually for evaluating the mean microfibril angle of the S2 layer to be overcome. It is expected that it will be possible to measure the microfibril angle distribution throughout the whole cell wall and also measure the average cell cross-section of a wood sample, by analysing (002) and (040) diffraction profiles in conjunction with each other.This work is supported by the NZ Foundation for Research, Science and Technology under contract # UOC 401 相似文献
5.
《Scandinavian Journal of Forest Research》2012,27(1-4):443-451
Spatial and temporal variation of N, P, K, Ca, Mg, Mn, Zn, B and Al concentrations in Scots pine (Pinus sylvestris L.) bark and stemwood was studied in three stands at different stages of development. Concentrations of the mobile nutrients N, P and K increased in stemwood and inner bark towards the youngest tissues vertically towards the top of the stem, and horizontally from the pith to the youngest annual rings. The concentrations of Ca, Mg, Mn and Zn were greatest in the oldest tissues and decreased horizontally towards the youngest annual rings. There was a slight increase of most nutrients near the divide between sapwood and heartwood. Seasonal nutrient variation was greatest in the inner bark. The highest nutrient concentrations occurred in winter and spring. Concentrations also varied with stand age, especially in the inner bark, being lowest in the oldest stand. 相似文献
6.
《Scandinavian Journal of Forest Research》2012,27(6):494-503
Abstract Genetic variation in wood density, microfibril angle (MFA), wood stiffness (MOE), height, diameter and volume was investigated in a 26-year-old Norway spruce [(Picea abies (L.) Karst.] clonal trial in southern Sweden. Wood quality measurements were performed on 10 mm increment cores using SilviScan. For MFA, mean values of annual rings showed the highest value (30°) at ring 2 counting from the pith, followed by a steep decrease and a gradual stabilization around ring 12 at approximately 14°. MOE showed a monotonic increase from 5 GPa to 14 GPa when moving from pith to bark. High broad-sense heritability values were found for wood density (0.48), MFA (0.41) and MOE (0.50). All growth traits displayed heritability values of similar magnitudes as reported in earlier studies. The generally high age–age correlations between different sections of the wood cores suggested that early selection for wood quality traits would be successful. Owing to unfavorable genetic correlations between volume and MOE, the correlated response indicated that selection for volume only at age 10 would result in a 0.27% decrease in weighted MOE at age 26 for every 1% increase in volume. 相似文献
7.
The chemical composition of needle and leaf litter from Scots pine, Norway spruce and white birch in Scandinavian forests 总被引：8，自引：0，他引：8
Needle litter from 14 stands of Scots pine (Pinus silvestris,L.), 13 stands of Norway spruce (Picea abies (L.) Karst.) andleaf litter from three stands of white birch (Betula pubescensEhrh.) were analysed for chemical composition. The concentrationsof the elements N, P, K, Ca, Mg and Mn as well as solid organiccomponents (lignin, cellulose and hemicelluloses) and solubleswere determined. When the average chemical compositions werecompared the Scots pine needle litter was clearly the most nutrient-poorlitter type. Of the solid organic-chemical components the ligninfraction dominated in the spruce and birch litter whereas thecellulose dominated in the pine needle litter. When Norway spruce and Scots pine were growing in adjacent standson soils with the same bedrock origin the spruce litter hadsignificantly higher concentrations of nutrients (N, P, K, Ca,Mg, Mn) than the pine needle litter. At sites where Norway spruceand white birch were growing in adjacent stands, the birch leaflitter had generally higher concentrations of nutrients. However, significant or nearly significant differences were onlyobtained for Mg (P = 0.002), K (P = 0.056) and N (P = 0.087),probably due to the few replicates of stands compared. Concerningorganic chemical components, the spruce needle litter had significantlyhigher concentrations of lignin and mannan than all the otherlitters and lower levels of ethanol-soluble substances, celluloseand galactan than the pine needle litter. Further, it had lowerconcentrations of water solubles, rhamnan and xylan than thebirch litter. No relationships were established between the nutrient statusof the conifer litters and the site index H100 (the dominantheight of the trees at a reference age of 100 years) of thestands. Concentrations of solid carbohydrates in the litterswere, however, positively correlated with site index (P <0.001). Further, the concentration of nitrogen in the pine needlelitter was negatively correlated with the latitude of the sites(P < 0.01). The influence of litter chemistry on the decompositionof litter and nutrient cycling of forests is discussed. 相似文献
8.
X-ray diffraction is a well-established method for the determination of the mean microfibril angle (MFA). When the sample is a slice of wood variations in the fibre orientation, the shape of the cells, and the measurement geometry affect the intensity curve. A general form for diffraction conditions in terms of angles describing the fibre orientation and the shape of the cell was derived. Intensity curves were calculated by using Monte Carlo method and compared with experimental ones. Both peak fitting and variance methods were used for determining the mean MFA from the intensity curves. Norway spruce was used as an example. Results indicate that deviations in the fibre orientation, the spiral grain, do not affect the mean MFA considerably when using the symmetrical transmission geometry. When using the perpendicular transmission geometry large deviations in spiral grain or tips tend to increase the MFA determined with the variance method and decrease the MFA determined with the fitting method. The shape of the cell should be considered when using the reflection 200 and the fitting method. The variance method is insensitive to the shape of the cell. 相似文献
9.
Marko Peura Klaas Kölln Ingo Grotkopp Pekka Saranpää Martin Müller Ritva Serimaa 《Wood Science and Technology》2007,41(7):565-583
The effect of strain on dry, clear Norway spruce (Picea abies [L.] Karst.) wood was studied by tensile testing along the cell axis and by in situ X-ray diffraction measurements. The mean
microfibril angle (MFA) was initially 3–12 degrees and did not decrease due to strain. Based on the positions of the reflections
200 and 004 of crystalline cellulose, cellulose chains elongated and the distance between the hydrogen bonded sheets of chains decreased
due to the strain. The elongation of the unit cell parallel to the cellulose chains was twice as high in juvenile wood as
in mature wood. The (X-ray) Poisson ratio ν
ca
for crystalline cellulose in Norway spruce was calculated from the deformation of the unit cell. The average ν
ca
of earlywood was 0.28 ± 0.10 in juvenile wood and 0.38 ± 0.23 in mature wood. In latewood, the average ν
ca
was 0.48 ± 0.10 in juvenile wood and 0.82 ± 0.11 in mature wood. The average ν
ca
values were not directly correlated to the crystallite dimensions or to the mean MFA in juvenile and mature earlywood and
latewood. The results show that the amorphous matrix has a definite effect on the deformation of cellulose crystallites. 相似文献
10.
杨树微纤丝角的变异及其与木材性质的相关关系 总被引：6，自引：0，他引：6
微纤丝角为细胞次生壁S2层微纤丝排列方向与细胞主轴所形成的夹角,与木材的物理性质、力学性质和化学性质都有着直接的关系。应用x射线衍射法测定了7个杨树无性系(14株样木)胸径处各年轮的微纤丝角,并对应分析和测定了各年轮的木材基本密度、纤维长度、纤维宽度和纤维素含量。研究结果表明,杨树微纤丝角在年轮间存在显著差异,其径向变异规律为从髓心向外以微纤丝角逐渐降低,年轮间的平均微纤丝角在7.8旱?8褐洌荒静幕久芏取⑾宋ざ取⑾宋矶群拖宋睾吭谀曷旨湟泊嬖谙灾钜臁O喙胤治霰砻鳎⑾怂拷怯肽静幕久芏取⑾宋ざ取⑾宋矶群拖宋睾看嬖谙灾母合喙毓叵??0.01),相关系数分别为-0.450、-0.586、-0.516和-0.660。回归分析结果表明,多项式方程可较好地描述杨树微纤丝角与所测定的木材性质的关系,相关系数均在-0.45以上(n=125)。本文的研究结果认为,在今后针对杨树材性改良的育种计划中,微纤丝角是一个重要的选育和改良指标。图3表3参34。 相似文献
11.
Godbold DL 《Tree physiology》1991,9(3):349-357
Root elongation of Norway spruce (Picea abies (L.) Karst.) seedlings was inhibited in the presence of 5 microM Cd, but was unaffected by a Cd concentration at 0.05 microM. Nutrient solutions labeled with (109)Cd were used to investigate the influence of pH, cations and the metabolic inhibitor 2,4-dinitrophenol (DNP) on the uptake of Cd by roots of intact spruce seedlings. Extracellular Cd was removed by washing the roots, and the relative amounts of Cd in the root apoplast and symplast estimated. In the presence of DNP, Cd uptake was reduced at 0.05 microM (non-toxic) but not at 5 microM Cd (toxic). At 0.05 microM Cd, the uptake of Cd into both the apoplast and symplast was dependent on the pH of the nutrient solution. Lower pH decreased Cd accumulation. Aluminum supplied at 100 or 500 microM lowered the Cd concentrations of both the apoplast and symplast. An increase in Ca or Mg supply reduced the Cd concentration of the apoplast but not of the symplast. In the presence of 5 microM Mn, the concentration of Cd in the symplast decreased by 44% compared to the control (1 microM Mn). High concentrations of Zn or Hg did not affect the Cd concentration of the roots. 相似文献
12.
The variation with height and radial distance from the pithof basic density and ring width has been determined in stemsof 48-year-old Sitka and Norway spruce planted at two spacingsat Durris, Kincardineshire. The pattern of radial variationof density was broadly similar at all heights: high near thepith, falling to a minimum and then a gradual increase. Themean whole-stem densities were significantly different at thetwo spacings in Sitka but not in Norway spruce. Density at breastheight was inversely correlated with ring width, strongly inSitka but weakly in Norway spruce. The density/ ring width regressionequation for outer wood in Sitka spruce at age 48 differed fromthat at age 31. In Norway spruce a high correlation was foundbetween whole-stem density and the density of rings 16–25at breast height. 相似文献
13.
R.F. Huettl S. Fink H.-J. Lutz M. Poth J. Wisniewski 《Forest Ecology and Management》1990,30(1-4):341-350
Since the mid-1970's new types of forest damage (of unknown origin) were observed in West Germany. Nonspecific foliage losses and foliar discolorations are the most common symptoms. This resulted in a comprehensive research program being initiated in the fall of 1983 to investigate the nutritional status of Norway spruce (Picea abies (L.) Karst.) stands in southwest Germany, growing on a variety of sites. Forests at these sites revealed light to moderate damage or acute site-and species-specific nutritional disturbances involving Mg, K, Ca, Mn, and Zn. Historical comparisons of needle-analysis data showed a dramatic change of the nutrient supply at many sites over the last one or two decades.
As a working hypothesis, the adverse impacts of air pollutants (e.g. photo-oxidants) and/or acidic atmospheric precipitation are seen as inciting factors causing increased leaching of nutrient elements. The tree's potential to compensate for the nutrient losses by increased uptake are limited by the often poor nutrient supply for forest soils. Accelerated soil acidification increase nutrient leaching from the soil, probably enhancing decline. Over a short period, fertilization led to a decrease or to the disappearance of the symptoms, and to the improvement in the nutrient composition of the foliage.
Microscopy investigation of Norway-spruce needles indicated the regeneration potential on a histological level for moderate yellowed needles after fertilization. Furthermore, needles of nutrient-deficient-trees reveal typical tissue damages different to those caused by SO2 or O3.
Acid mist increased the leaching of K, Ca, Mg, Mn, and Zn from the foliage. Even when nutrients are being leached from the foliage, nutrient uptake canbe increased by improving the nutrient supply in the soil.
Preliminary studies on the effects of damages caused by ozone (O3) on ponderosa pine suggest imbalance in micronutrient concentrations of foliage. 相似文献
14.
《Scandinavian Journal of Forest Research》2012,27(3):276-281
Different classification systems for Norway spruce (Picea abies (L.) Karst.) pulpwood were compared. The classification systems were applied on truckloads or single logs in southern Sweden. Truckload classification according to mean annual growth ring width gave better separation of the wood properties basic density, juvenile wood and dry matter content, than classification according to harvest type (first thinning, later thinning or final felling). The assortments did not have significantly different wood brightness. Sorting at log level according to diameter, mean annual growth ring width or number of annual growth rings, which could be done at harvesting, did not drastically improve differentiation of the mean values of the wood properties or reduce variance compared to truckload classification. The variation in wood properties within assortments remained large owing to the large variation in wood properties between and within logs. Substantial reduction in dry matter variation could be achieved by truckload classification during the summer. 相似文献
15.
Gunnar Thelin Ulrika Rosengren Ingeborg Callesen Morten Ingerslev 《Forest Ecology and Management》2002,160(1-3):115-125
Atmospheric deposition of N and S appears to have caused nutrient imbalance in Norway spruce stands in southern Sweden. This calls for a change of forest management to procedures that promote nutrient balance. Studies have shown lower soil acidity in Norway spruce/deciduous mixed stands than in spruce monocultures, but the tree nutrient status in such mixtures has not been much investigated so far.
The nutrient status of Norway spruce foliage and top mineral soil chemistry in monocultures and in stands mixed with beech, birch, or oak was investigated through paired comparisons on 30 sites in southern Sweden (27 sites) and eastern Denmark (three sites). In total, 45 mixed stands and 34 pure stands were included in the study.
Spruce needles from mixed stands had higher concentrations and ratios to N of K, P, and Zn than needles from pure spruce stands. Among the mixed stands, the K status appeared to be positively correlated with the percentage of deciduous tree basal area. Soil samples from mixed stands had a higher Mg concentration, base saturation, and BC/Al ratio than soil samples from pure stands. The spruce needle nutrient status was comparable in pure stands on fertile sites and in mixed stands on poor sites. We did not detect any differences in spruce tree growth between pure and mixed stands.
This paper discusses possible reasons for a positive effect on the tree nutrient status in mixed-species stands and the possibility of using mixed-species stands as a forest management procedure to avoid nutrient imbalance. 相似文献
16.
《Wood material science & engineering》2013,8(3-4):204-210
Abstract Untreated Scots pine (Pinus sylvestris) and Norway spruce (Picea abies) samples were exposed above ground in a durability test for 6 years. The samples consisted of three pieces of wood, 22×95×500 mm, screwed together; two pieces lengthwise with a third piece overlapping. Weight was measured, to calculate moisture content (MC), and samples checked regularly for cracks and fungal growth. Parameters investigated were heartwood/sapwood (pine), annual ring orientation (spruce), stand site, annual ring width and density. Stand site, annual ring width and density had no influence on MC or fungal growth for either pine or spruce. Spruce samples with vertical annual rings had fewer cracks than samples with horizontal annual rings. Pine sapwood samples had a high MC and a large amount of rot fungi, while heartwood had a lower MC and no rot. Most spruce samples were similar to pine heartwood, except from a few samples that had high MC and fungal growth. Those were all sawn from the outer part of the log. Therefore, it can be stated that spruce sawn from the inner part has almost the same properties as pine heartwood, while spruce from the outer part of the log has similar properties to pine sapwood. 相似文献
17.
The spatial distribution of plant-available mineral nutrients in forest soils is often highly heterogeneous. To test the hypothesis that local nutrient enrichment of soil leads to increased root proliferation in the nutrient-rich soil zone, we studied the effects of nutrient enrichment on the growth and nutrient concentrations of Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco), Scots pine (Pinus sylvestris L.) and Norway spruce (Picea abies (L.) Karst.) roots. Three-year-old seedlings were grown for 9 months in split-root containers filled with nutrient-poor forest mineral soil, with one side supplemented with additional mineral nutrients. Root dry weight and root length in Scots pine and Norway spruce were increased in the nutrient-supplemented soil compared with the nonsupplemented side, whereas root growth in Douglas-fir was unaffected by nutrient enrichment. Of the three species examined, Norway spruce exhibited the highest root and shoot growth and the highest nutrient demand. Specific root length (m g(-1)) and the number of root tips per unit root length were not affected by local nutrient addition in any of the species. Despite increased root growth in Norway spruce and Scots pine in nutrient-supplemented soil, their root systems contained similar nutrient concentrations on both sides of the split-root container. Thus, coniferous trees may respond to local nutrient supply by increased root proliferation, but the response varies depending on the species, and may only occur when trees are nutrient deficient. As a response to local nutrient enrichment, increases in root dry matter or root length may be better indicators of pre-existing nutrient deficiencies in conifers than increases in root nutrient concentrations. 相似文献
18.
Henrik R. Hallingbäck Karl-Anders Högberg Harald Säll Johan Lindeberg Marie Johansson Gunnar Jansson 《European Journal of Forest Research》2018,137(4):553-564
In breeding Norway spruce, selection for improved growth and survival is performed at age 10–15 years in order to optimize genetic gain per year. We investigated whether a selection based on wood traits such as density and grain angle, measured under bark in the field at the same age would be informative enough with respect to structural quality traits of sawn boards. To achieve this objective, a sawing study was conducted on the butt logs of 401 trees from a 34-year-old Norway spruce progeny trial situated in southern Sweden. Stem discs were excised from the top of the logs and radial profile data of grain angle, and wood density was recorded for specific annual rings. The sawn and dried boards were assessed for structural traits such as twist, board density, bending stiffness (static modulus of elasticity, sMoE) and bending strength (modulus of rupture, MoR). Additive genetic correlations (ra) between single annual ring density measurements and board density, sMoE and MoR were consistently strong (ra>?0.7) for annual rings 5–13. Genetic correlations of similar magnitude between grain angle and board twist were estimated for all investigated annual rings (from 2 to around 26 under bark). Consequently, it was found that indirect selection for wood density and grain angle at the tree age 10–16 years would result in more genetic gain per year than selection at later ages. This makes it feasible to perform simultaneous selection of progeny in the field for both growth and wood traits at similar ages. 相似文献
19.
《Scandinavian Journal of Forest Research》2012,27(1):14-29
Genetic parameters were estimated for wood and growth traits in two 19-yr-old clonal trials and a 40-yr-old full-sib progeny trial of Norway spruce [Picea abies (L.) Karst.]. In the clonal trials high (>0.4) broad-sense heritabilities were found for wood density traits, lignin content, number of internal cracks, growth traits, spiral grain and number of resin canals. Moderate (0.2–0.4) heritabilities were found for tracheid lumen diameter and cell wall thickness, microfibril angle and tracheid length, while low heritabilities (<0.2) were found for pulp yield, fibre strength, wood stiffness and wood colour. Lignin content and pulp yield showed low genetic variation, whereas the genotypic coefficient of variation for most other traits ranged between 5 and 15%. Most traits showed low levels of genotype by environment interaction. Among the wood properties, latewood proportion, earlywood density and ring density showed significant, adverse correlations with volume in both clonal trials. 相似文献
20.
Marjoriitta Mttnen Tarja Lehto Pedro J. Aphalo Mikko Kukkola Eino Mlknen 《Forest Ecology and Management》2003,180(1-3):401-412
The effects of boron (B) fertilizer applied 10 growing seasons earlier were studied in mature Norway spruce (Picea abies (L.) Karst.) trees in long-term factorial fertilization experiments at two field sites. Needle nutrient status, above-ground and below-ground growth and δ13C and carbon concentrations in the annual rings were measured. Needle B concentrations varied between 4 and 19 mg kg−1 on the plots that had not received B fertilization. On the B-fertilized plots they varied between 15 and 39 mg kg−1. The lowest B concentrations were on the plots that had received N or NCa fertilization. Needle Mn and Zn concentrations were lower on the B plots than on the plots that had not received B fertilization, although not significantly. Mean annual volume growth was slightly higher on the B plots at the more fertile site, but not at the less fertile one. The living:dead fine root mass ratio and living fine root length were also higher on the B-fertilized plots than on the unfertilized plots, but δ13C was not significantly affected, suggesting that the water status of the trees was not markedly altered by the increase in root growth. The carbon concentration in the annual rings was higher in the B-fertilized trees than in the unfertilized ones, suggesting the importance of B for wood formation. 相似文献