摘要:

The influence ofFagus sylvaticaL.,Quercus roburL.,Carpinus betulusL.,Tilia cordata Mill.andAcer platanoidesL. on pH(KCl) and organic matter content in the topsoil (0 to 5 cm), was studied at 70 mixed deciduous forest sites with different soil properties in the province of Scania, south Sweden. Samples at 50, 150 and 250 cm from the trunk were collected under canopies of individuals of different tree species growing side by side on initially similar soil. Analysis of differences included pairwise comparisons on each site. Compared toQ. robur,pH was 0.26 (at 50 cm) and 0.13 (at 150 and 250 cm) units lower forF. sylvatica. Acer platanoideshad 0.15 andT. cordata0.39 units higher pH thanQ. robur,as means of all distances. All differences were highly significant.Carpinus betulushad pH values very similar toQ. robur.The differences in soil organic matter content between the tree species were small and not significant.

ISSN:0282-7581    

DOI:10.1080/02827589409382806

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

The influence of tree species and soil properties on leaf litterfall concentrations and fluxes of elements were studied in three mixed deciduous forest stands. Leaf litterfall fluxes of sixteen elements were measured during autumn defoliation in 100 to 150 yr old individuals ofFagus sylvaticaL.,Quercus roburL.,Carpinus betulusL.,Tilia cordataMill, andAcer platanoidesL. Compared to throughfall and precipitation, leaf litterfall dominated the flux of P, Ca, Mn, N and Mg (in decreasing order) to the soil below the tree canopies. For K and especially S and Na, however, the importance of leaf litterfall input to the total fluxes was small. Fluxes and especially concentrations of Ca, Mg, K, P and partly N were positively related to base saturation of the soil, while Mn was negatively related duetoa higher mobilization rate and plant uptake of this element on acid soils. Litterfall fluxes forC. betuluswere strongly positively influenced by base saturation and fluxes were usually higher than forF. sylvaticaandQ. roburat the richest site.Quercus roburhad often the lowest fluxes, especially of Ca and Mg.Tilia cordatahad the highest leaf litter concentrations in twelve of the sixteen elements, and the highest fluxes particularly of N and K.Acer platanoideshad the highest or among the highest concentrations and fluxes of Ca, Zn and Mn. The concentration of Al inC. betulusleaf litterfall, was about five times higher than in all other tree species at all sites.

ISSN:0282-7581    

DOI:10.1080/02827589409382807

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

Greenhouse experiments were carried out to study the effects of geographical origin and parent trees on the autumn frost hardening ofPinus sylvestris(L.) seedlings after their first growing season. Artificial freezing with impedance measurements and visual needle injury classification were. used to measure frost hardiness. There were significant differences in the timing of hardening between the forest populations. The origin of the male parents had a significant effect on freezing injury, indicating that early freeze testing can be used to evaluate the frost hardiness of seed orchard crops with pollen contamination. The hardiness of the offspring from controlled crosses was, however, lower than that of the stand controls. There were significant differences in frost hardiness between parent clones.

ISSN:0282-7581    

DOI:10.1080/02827589409382808

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

Genetic correlations were calculated between five phenologicai traits and two growths capacity traits at the ages 3–8 years in a nursery trial with full‐sib families ofPicea abies(L.) Karst. from a 9 × 9 factorial mating. The parents originated from three regions, northern Sweden, central Sweden and central Europe, each region being represented by six parents. Out of the possible 81 crosses 57 were analysed. Genetic correlations were calculated between traits within a year at population and within‐population levels and between the same trait over years, both among and within populations. At the population level, most correlations were close to one. Within populations between individual parent trees, the correlations between the timing of the growth initiation and the growth midpoint stages were positive and strong with one exception. In most years these stages were also strongly positively correlated with growth cessation. Correlations between growth rhythm and duration of the shoot elongation period were as a rule weaker. In most years, there were weak genetic correlations between growth rhythm and height or leader length. The genetic age‐age correlations were consistently high for all growth rhythm traits except for the shoot elongation period, which was inconsistent, as was the leader length. The results indicate that selections for certain trait combinations in the nursery among populations from widely different geographic regions can be made as early as at ages 3–4, and the trait that is simplest to assess can be used.

ISSN:0282-7581    

DOI:10.1080/02827589409382809

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

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.

ISSN:0282-7581    

DOI:10.1080/02827589409382810

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

Two‐ to three‐week‐old seedlings ofPicea abies, Pinus sylvestrisandPinus contortawere inoculated with the supervirulent strainAgrobacterium rhizogenesR1600 2cm above the base of the hypocotyl; other treatments included inoculation withAgrobacterium tumefaciensstrain A281 (pTVK291) or mock inoculation. Hairy or highly branched roots formed on 2–3% of seedlings of all 3 species that were infected by R1600 but on none of the other seedlings. Normal adventitious roots were also induced on 5–10% ofAgrobacterium‐treated seedlings but none appeared on the other seedlings. Opine assays and growth rates of hairy and normal roots indicated that only roots with the hairy morphology were transformed.

ISSN:0282-7581    

DOI:10.1080/02827589409382811

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

Seventeen‐week‐old black spruce seedlings were hardened under short daylengths and one of three short day length environments, which were either warm (24/16°C, day/night) throughout a 10 week hardening period (WW), cool (10/5°C) throughout hardening (CC), or warm for three weeks followed by seven weeks of cool temperatures (WC). Greatest root and shoot frost hardiness resulted from the exposure of seedlings to three weeks of warm followed by seven weeks of cool temperatures. Seedlings receiving warm temperatures throughout hardening increased in root and shoot frost hardiness, but to a lesser extent than seedlings exposed to cool temperatures. The frost hardiness of woody roots was generally greater than that of fine roots, but the extent of the difference in frost hardiness depended on the time since bud initiation and on the hardening treatment.

ISSN:0282-7581    

DOI:10.1080/02827589409382812

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

Two experiments (Expt 1, Expt 2) with supplemental mass pollination (SMP) were carried out in a seed orchard ofPinus sylvestrisL. in order to assess the biological and operational prospects for SMP. The success of the SMP was studied by means of allozyme markers. In Expt 1 the pollen mix was applied very close to each female strobilus. The estimated success rates for treatments varied between 66% and 84%. When supplemental pollination was done at peak receptivity, one single pollination was enough to obtain high success rates. In Expt 2 the pollen mix was dusted over clusters of receptive strobili on whole‐trees. The estimated success rates for treatments varied between 10% and 23%. The success rates improved when the trees were pollinated on more than one occasion per day during the receptive period. The overall conclusion is that SMP is practical forP. sylvestrisseed orchards.

ISSN:0282-7581    

DOI:10.1080/02827589409382813

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

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.

ISSN:0282-7581    

DOI:10.1080/02827589409382814

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

The quality of most forest sites in Sweden is classified by means of site properties, according to a system developed in the 1970's. Although its regression functions show good accuracies on country‐wide sample plot materials, the local precision in the system is shown to be low. An alternative model that utilizes digital map information is suggested, and results from a study in central Sweden are presented. Independent variables were derived from a Digital Elevation Model, a Geochemical Survey and a Quaternary Deposit Map. The site indices could be considerably better estimated forPinus sylvestriswith the map method (R2= 0.41), as compared to the existing system (R2= 0.09). ForPicea abiesthe degree of determination was equally low for the two methods.

ISSN:0282-7581    

DOI:10.1080/02827589409382815

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor