Self‐thinning models for even‐aged stands of Pinus sylvestris, Picea abies and Betula pendula

1993 ◽  
Vol 8 (1-4) ◽  
pp. 326-336 ◽  
Author(s):  
Jari Hynynen
World Science ◽  
2019 ◽  
Vol 1 (3(43)) ◽  
pp. 40-45
Author(s):  
Мегалінська Г. П. ◽  
Пакірбаєва Л. В. ◽  
Білик Ж. І. ◽  
Даниленко Є. В. ◽  
Гатальська Є. О.

The results of the study of phytotoxic effects of water extracts from Pinus sylvestris L., Betula pendula Roth, Quercus robur L., Picea abies (L.) Karst. P. excelsa Link, Carpinus betulus L., Robinia pseudoacacia L., Populus tremula L., Crataegus submollis L. are presented. For а comparison of the phytotoxic activity of the investigated plants was used to measure the change in the intensity of the mitotic division, depending on the concentration of aqueous extraction of plant material (tangent trend curve of cytostatic activity). According to this parameter, the following row of phytotoxic activity of wood species can be ordered: Populus tremula, Betula pendula, Robinia pseudoacacia, Carpinus betulus, Acer platanoides, Tilia cordata, Pinus sylvestris. Water extract Quercus robur and Picea abies have discovered a phyto-stimulating effect. The results of the study allow us to discuss the possibility of introducing the parameter of the phytotoxicity coefficient to determine the allelopathic effect in the tree-tree system.


2019 ◽  
Vol 39 (7) ◽  
pp. 1262-1271 ◽  
Author(s):  
Andreas Bär ◽  
Monika Hamacher ◽  
Andrea Ganthaler ◽  
Adriano Losso ◽  
Stefan Mayr

Abstract Electrical resistivity (ER) tomography is a promising technique to minimally invasively study stems of living trees. It allows insights into xylem properties based on the cross-sectional distribution of ER that is governed by the wood’s electrical conductance. In this study, ER measurements were carried out on four forest tree species, Betula pendula, Fagus sylvatica, Picea abies and Pinus sylvestris, to demonstrate interspecific, intraspecific and within-tree variation of ER tomograms. Further, ER patterns were linked to xylem moisture content (MC), electrolyte content and density obtained from wood core analyses. The ER patterns of both coniferous species, P. abies and P. sylvestris, were found to be more homogenous and concentric compared with the complex tomograms of angiosperms. However, the ER range of coniferous trees showed considerable intraspecific variation. Measurements near ground level showed pronounced effects on ER tomograms, highlighting the importance of the chosen measurement height. A strong relation between ER and wood density was found in F. sylvatica while ER patterns of conifers were mainly influenced by MC. Results demonstrate a high species specificity of ER tomograms and of respective influencing xylem traits. They underline the importance of reference measurements for a correct interpretation of ER studies.


2004 ◽  
Vol 34 (12) ◽  
pp. 2573-2586 ◽  
Author(s):  
Helena Dehlin ◽  
Marie-Charlotte Nilsson ◽  
David A Wardle ◽  
Anna Shevtsova

We performed a pot experiment to study the effects of varying levels of vegetation shade and humus fertility, simulating natural conditions of the boreal forest, on growth, interspecific competition, and ectomycorrhizal colonization of seedlings of three coexisting tree species: Pinus sylvestris L., Picea abies (L.) Karst., and Betula pendula Roth. In contrast to late-successional Picea abies, early-successional species Pinus sylvestris and particularly B. pendula responded to shade with an increase in stem height and with some changes in biomass, especially in the high-fertility humus. Humus fertility had greater effects on biomass of seedlings than did shade treatments. Interspecific competition among pairwise combinations of the three species was greatest in the high-fertility humus, but was not affected by shade. Betula pendula was the strongest competitor among species; it was not affected by the presence of coexisting species and strongly suppressed coniferous seedlings, especially in the high-fertility humus. Generally, ectomycorrhizal colonization was not affected by shade treatments, but was highest in the low-fertility humus. These results show that effects of light, humus fertility, and presence of neighbours are species specific, and these differences are important for the competitive and recruitment abilities of seedlings of coexisting tree species and ultimately for the species composition of developing forests.


2000 ◽  
Vol 78 (11) ◽  
pp. 1440-1449 ◽  
Author(s):  
Ann Helén Österås ◽  
Lars Ekvall ◽  
Maria Greger

This study compared the sensitivity to, and uptake and distribution of, cadmium (Cd) in three tree species, Norway spruce (Picea abies (L.) Karst.), Scots pine (Pinus sylvestris L.), and European white birch (Betula pendula Roth), as well as different populations of these species. Seedlings of each species from three regions (southern, central, and northern parts of Sweden) were cultivated in nutrient solution and treated with varying concentrations of Cd. Sensitivity was determined by using the Weibull function on root and shoot dry weight and root length measurements. Cd uptake and translocation were analysed. The results on root sensitivity revealed that birch and spruce were the least and most sensitive species, respectively, to both the external and tissue levels of Cd. In terms of shoot sensitivity, however, birch was the only species affected by Cd, i.e., the most sensitive species. Pine and birch had similar Cd uptake, while spruce had lower uptake and translocation of Cd compared with the others. There were also differences in sensitivity within the species. The central ecotype of all species tended to be the most Cd resistant. The central ecotype of spruce and birch had the lowest Cd uptake, whereas the central ecotype of spruce and pine had the lowest translocation of Cd to the shoot.Key words: birch, cadmium, pine, sensitivity, spruce, uptake.


Sign in / Sign up

Export Citation Format

Share Document