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1.
挪威云杉种源及家系种子播种品质的研究   总被引:1,自引:0,他引:1  
通过对引进的芬兰挪威云杉5个种源和窄冠垂枝挪威云杉10个家系种子播种品质的方差分析和聚类分析研究表明,挪威云杉种源和窄冠垂枝挪威云杉家系种子净度达98%以上。种子的播种品质与地理分布和起源有关。由北向南种子的千粒重增加、发芽率提高、死亡率下降。另外,天然起源的种子播种品质低于种子园的种子。窄冠垂枝挪威云杉因天然分布区域极为狭窄、种群规模过小,导致由其它因素造成的未萌发百分率高。  相似文献   

2.
Seedling of Norway spruce (Picea abies L.) were grown under three different light qualities in fluid-roof growth chambers. Blue light with a high red/far-red ratio decreased shoot length as well as total plant dry weight compared to natural light. Yellow light with a low blue/red ratio did not significantly affect the plants. The effects of light quality were generally the same at 18, 24 and 28 °C day temperature. Plant growth was reduced at temperatures above 24 °C.  相似文献   

3.
Allozymes of Swedish seed orchard clones of Norway spruce (Picea abies Karst.) were studied. There were differences between gene frequencies of origins from different regions. The gene pool of the fertilizating pollen of two different orchards was different. Pollen contamination and outcrossing rates were estimated in two seed orchards. The fraction of paternal gametes which did not originate from any seed orchard clone was 10% and 17%, respectively. Based on simulation it was estimated that only a quarter of the gametes with origin outside the orchard would be detected. Estimation of multilocus outcrossing rates were 0.95 and 0.98.  相似文献   

4.
    
The effects of initial spacing and tree class on the basic density of Norway spruce were evaluated in a stand on a fertile site in southwestern Sweden. The basic density at 0 and 4 m above ground level was significantly higher for trees planted with an initial spacing of 1.5 m than for trees planted with wider initial spacings. A decrease in initial square spacing from 2.5 m to 1.5 m had little effect, of small practical importance, on the basic density. The density at 0 and 4 m above ground was significantly higher for the suppressed trees than for the intermediate and dominant ones, and for the intermediate trees compared with the dominant trees. Differences in basic density appeared to be due mainly to differences in growth‐ring width. Basic density decreased outwards from the pith to the bark at 1.3 and 4 m above ground.  相似文献   

5.
Seven‐year old cuttings of pendula spruce were taller and had larger diameters than seedlings or cuttings of Norway spruce of normal crown type. Pendulous cuttings still had plagiotropic growth at age 7 years and the rate of change to orthotropic growth form was weaker than in cuttings with normal crown type. In pendulous cuttings the effect of the origin of ortet and clone on the crown symmetry was significant at age 5 years but not at age 7 years. The effect of clone on the growth form was evident at ages 5 and 7 years, but the effect of the origin of ortet was significant only in 7‐year‐old cuttings. There were no differences in plagiotrophy between clones from 4‐ and 7‐year‐old ortets. For pendulous cuttings the average height and diameter growth decreased in 5‐ and 6‐ year‐old cuttings with less pendulous crown form and with more plagiotropic growth form but this decrease had almost disappeared in 7‐year‐old cuttings.  相似文献   

6.
The effect of air pollutants on conifers was studied throughout the year near industrial point‐sources using two types of half‐open chambers for excluding wet or dry deposition around selected trees. Results indicate that pollutant uptake from dry deposition and wash‐off effect by rain have overriding influence in the internal accumulation of pollutants by needles. The exclusion of wet deposition substantially enhanced pollutant accumulation in the needles and suggests that wet deposition itself has a minor direct effect on accumulation near point‐sources. Near the fertilizer plant the trees growing in filtered air exhibited fewer visible symptoms and had lower accumulations of fluoride. This suggests that decreasing the gaseous air pollutants would improve the condition of conifers at this site. Results suggest also that besides high needle pollutant content, winter conditions are needed to facilitate visible injury development.  相似文献   

7.
Somatic embryos were obtained from young, isolated cotyledons of Picea abies. A bud-inductive treatment for one week before transfer to a callus induction medium, resulted in a tenfold increase in the percentage of cotyledons in which embryonic tissues could be induced. The degree of expression of somatic embryogeny depends on whether cotyledons are first subjected to a callus-inducing medium or first exposed to a cytokinin treatment followed by a callus-inducing medium. It is hypothesized that two populations of cells exist, both with the inherent potential of becoming embryogenic after treatment with plant growth regulators.  相似文献   

8.
    
This study provides an analysis on the variability of structural timber of Norway spruce (Picea abies) grown in Norway. Density, modulus of elasticity (MOE) and bending strength were measured on 1188 boards from 205 trees, sampled from 14 sites throughout Southern Norway, Eastern Norway and Trøndelag. The area represents the procurement area for the majority of Norwegian sawmills. The variability of the timber properties was analysed in a linear mixed model where the random variance was divided into variance due to site, variance due to trees and within-tree variance. Models describing variance due to site based on site index, altitude and latitude were developed, and combined with data from the Norwegian National Forest Inventory to estimate mean values and variability of the timber properties. The results showed that major parts of the variance due to site are explained by altitude and site index, and for density also by latitude. Major parts of the variance due to site and the variance due to trees in bending strength and MOE were explained by density.  相似文献   

9.
用材树种一般约需10年或更长时间才能正常开花结实。提早开花,缩短育种世代是林木育种的重要课题。早在50年代,已有试验证明GA处理柳杉和柏类能促进开花结实。自70年代以来对促进主要用材树种开花结实作了大量的试验,表明用极性较弱的赤霉素GA_4、GA_7,结合采用提高温度、降低土壤水分、环剥和断根等栽培措施,也能促进松、云杉、花旗松等树种的结实,在松科5属17种中已见效果。  相似文献   

10.
The effects of stand density on increment and branch properties were studied in three spacing experiments of Norway spruce [Picea abies (L.) Karst.]. The stand densities ranged from 350 stems ha−1, regarded as open-grown trees, up to 1,600 stems ha−1, corresponding to the density recommended for forestry practice. Properties of all the branches were measured from the stem apex downwards. The study material included a total of 5,661 branches from 45 trees. Increasing stand density resulted in a decrease in radial increment as well as shorter and narrower crowns, but it had no effect on height increment. The average number of spike knots per tree was 0.87, 0.27, and 0.33 in densities of 350, 700 and 1,600 ha−1, respectively. Additionally, in the widely spaced stands of 350 stems ha−1, the fraction of trees having spike knots was high (over 50%). At a density of 1,600 ha−1, the sample trees had somewhat less branches in a whorl compared with the more widely spaced plots. The most pronounced effect of stand density was the increase in branch diameter with decreasing stand density. At a density of 350 ha−1, the maximum branch diameter of all the sample trees exceeded the diameter limit of quality class B in the European quality requirements for round wood. The results give some indication that trees subjected to severe competition would produce smaller branches per unit of crown projection area. However, the possibilities for reducing branch dimensions relative to stem and crown size through competition appear quite restricted.  相似文献   

11.
    
Nutrient removal has been one of the key issues since the harvesting of logging residues started in Sweden. This study examined the actual removal of nutrients by measuring the amounts of biomass removed (from a forest products perspective) combined with their respective nutrient concentrations (N, P, Ca, K and Mg), from a clear-felled area when using the dried-stacked and fresh-stacked methods. The most important finding is that the two methods were very similar regarding nutrients remaining at the clear-felled area. Of the nutrients remaining there, most were found to be well distributed between the harvester heaps. Both methods fulfilled the requirements of the Swedish Forest Agency. A sensitivity analysis showed that even if the dried-stacked method left more needles, or the fresh-stacked method extracted more logging residues, there would only be a small impact on the levels of nutrients removed. The sensitivity analysis also showed that the amount of logging residues remaining between the harvester heaps seems to be much more important for nutrients left behind, regardless of extraction method. With this in mind, it is highly probable that improvements to the extraction of logging residues, without increasing nutrient removal, can be made.  相似文献   

12.
A transition matrix model of an uneven‐aged Norway spruce (Picea abies (L.) Karst.) stand is presented. The transition probabilities are based on material from 48 study plots in eastern Finland. The ingrowth of the transition matrix is based on material from 8 study plots and on previous studies. In the model runs the sustainable harvest proportion for 5 years varied between 7 and 20% of the stocking depending on the stand basal area. The shape of the stand diameter distribution had no notable effect on the sustainable harvest proportion. The extension of the thinning interval from 5 to 10 years slightly reduced the total removal during the simulation time.  相似文献   

13.
Old provenance experiments with Scots pine and Norway spruce in Finland were used for assessing the long‐term effects of the projected climatic change on forest trees. The northernmost origins showed an increase in wood production when transferred southwards into a climate with an annual mean effective temperature sum close to that which is expected in northern areas as a result of the projected climatic change. A model is constructed with the estimated changes in wood production as a function of the annual mean temperature sum at the original location and the change in the annual mean temperature sum caused by the geographical transfer. The major changes in wood production are expected to occur in the northernmost areas of tree growth.  相似文献   

14.
Variation in the growth ring width, basic density, longitudinal shrinkage and tracheid length was investigated in the juvenile wood of Norway spruce samples taken from different heights in the stem. Annual height increments were cut from the ten youngest shoots from trees of three different heights. By this method the properties of an individual growth ring could be analysed without taking samples from each ring. Sixteen tree tops of an average stem height of 8, 15 and 25 m were analysed. Basic density was low in the first shoot, highest in the second or third one and decreased gradually thereafter. Longitudinal shrinkage was highest close to the pith and decreased to about 0.2% in the outer rings. Tracheids were only ca. 1 mm long close to the pith and their length increased sharply towards the tenth shoot. The properties of juvenile wood varied with the height in the stem. Longitudinal shrinkage around the pith seemed to increase with increasing height and basic density was highest at 25 m stem height. The applicability of the method for the calculation of basic density and tracheid length in individual growth rings close to the pith is discussed.  相似文献   

15.
    
Abstract

Using data from nine spacing experiments of Norway spruce (Picea abies (L.) Karst.) in Norway, covering wide ranges of site index and initial spacing, this study evaluated stand basal area and volume responses to initial spacing and examined whether these responses varied by stand ages or site quality. We developed nonlinear regression models that described the standing basal area or volume responses to initial spacing along with site index and stand ages. The results show that closer spacings produced higher standing basal area and volume than wider spacings. The response curves are highly nonlinear in younger stands and become nearly linear in mid-rotation stands, indicating stronger responses at younger ages and weaker responses as age increases. Furthermore, for young stands, spacing effects are stronger at closer than at wider spacings. The basal area and volume responses to initial spacing tend to be similar across site indices. However, the interaction of site index and stand age on spacing responses makes it difficult to isolate the effect of site index on spacing responses. Mortality is higher and begins earlier at closer spacings than wider. The mean diameter of the largest 100, 400, 600, and 800 trees ha?1 increased with spacing in three out of the nine experiments. Dominant height did not vary by initial spacing for any of the experiments. The findings suggest that the extra volume production in stands of closer initial spacing is restricted to early stand development.  相似文献   

16.
The purpose of this study was to understand the variation in root litter mass‐loss rates in a climatic transect across a large region ranging from the Arctic Circle (66°N) in Scandinavia to Berlin (52°N) in north‐east Germany, dominated by coniferous monocultural forests. To investigate the combined influence of litter quality and climate, data were used from 37 sites and plots at which root litters of three coniferous species (Pinus sylvestris, Pinus contorta and Picea abies) had been incubated. In spite of the considerable climatic differences among sites, there were no strong relationships between any climatic variable and the lst‐yr mass loss (range 17.0–40.9%). For the lst‐yr mass loss, the average annual temperature was the most rate‐regulating factor for all litter combined, with a value for R 2 adj of 0.186. Substrate quality also had an influence. Thus, for the whole region lignin concentration was significant, with a value for R 2 adj of 0.142. For the separated groups of pine and spruce stands the value for r 2 increased but the factor average temperature still dominated and for pine the R 2 adj reached a value of 0.346. Over the region N concentration in the fresh pine root litter was significant (R2 adj = 0.232). For the root litter of P. abies the average temperature in July was the strongest rate‐regulating climatic factor, with a value for R 2 adj of 0.381. A combination of temperature in July and the initial P concentration in the litter gave an R 2 adj value of 0.713 for P. abies litter, thus explaining about 71% of the variation.  相似文献   

17.
The effects of red (R), far‐red (FR) and R + FR light on Norway spruce seed dormancy were studied at five different moisture contents (MC) between 5 and 20%. The degree of dormancy was studied by germinating seeds over a wide range of temperatures in the dark. The non‐irradiated control seeds were shallowly dormant, only a proportion of them germinated and within a limited temperature range. Red light progressively stimulated germination between 5 and 17% MC, but this effect was reversed if a FR treatment followed, although all germination could not be inhibited by one FR pulse. Far‐red light had a slightly stimulating effect at 19% MC. To generate seeds able to germinate over a wide range of temperatures in darkness, an artificial light pretreatment should be given to seeds at MC above 17% in order to receive maximum response.  相似文献   

18.
在室内控制条件下研究含水量和温度对富含NH^+4的严重酸化挪威云杉林枯枝落叶层物质饱和是液PH值的影响,包括未分解层OL,半分解层OF和已分解层OH,在为期1a的实验期间内没有元素的输入,淋失和根系吸收,但可相对自由地进行气体交换。  相似文献   

19.
    
Pathogenicity of cherry‐spruce rust, Thekopsora areolata, was investigated by inoculations with aeciospores from seven Norway spruce, Picea abies, seed orchards that had suffered from successive severe rust epidemics in the 2000s in Finland. Detached leaves of Prunus spp. were inoculated in the laboratory using aeciospores from cones of various ages. In the greenhouse, live Prunus padus plants were inoculated, and possible autoecism of the rust was tested by inoculations of Picea abies seedlings. Thirty‐five spore sources from the seed orchards formed uredinia on Prunus spp. in the laboratory 2 weeks after incubation, but no telia developed. In the greenhouse, uredinia developed on live P. padus, but no rust symptoms, cankers or sporulation were detected on Picea abies. Thus, no evidence of autoecism was observed among the T. areolata populations and therefore all populations, suggesting all those tested from the Finnish seed orchards were heteroecious.  相似文献   

20.
Self‐thinning models were developed to describe the relationship between the stem number and mean diameter of even‐aged and monospecific tree stands undergoing self‐thinning. The models were developed separately for Pinus sylvestris L., Picea abies (L.) Karst. and Betula pendula Roth. stands. Data from 41 unthinned permanent sample plots were used. According to Reineke's equation and the —3/2 power rule of self‐thinning, a log‐log plot of average tree size and stem density will give a straight, self‐thinning line of constant slope. According to this study, the slope of the line consistent with Reineke's equation varies for different tree species. Within tree species, the intercept of the self‐thinning line varies according to site index.  相似文献   

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