Effects of shading and humus fertility on growth, competition, and ectomycorrhizal colonization of boreal forest tree seedlings

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.

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.


2014 ◽  
Vol 60 (No. 12) ◽  
pp. 540-543
Author(s):  
I. Tomášková ◽  
J. Vítámvás ◽  
J. Korecký

:Germination capacity and germination energy are usually the most frequently used quantitative parameters of forest tree seed. With seed ageing both parameters decreased and the rate of the collapse is given by tree species, age of tree and its seed and biotic and abiotic factors. Relatively little attention has been paid to the age of seed. As it was found, the longevity of the main tree species remained relatively high, and spruce (Picea abies [L.] Karsten and pines (Pinus sylvestris L.) from the investigated areas across the Czech Republic maintained minimally one third of germination capacity or germination energy during the 10 years with the exception of larch (Larix decidua Mill.) where germination capacity decreased almost to zero after 10 years. Although the germination energy and germination capacity decreased significantly, it is possible to use the seed in the case of shortage of the seed of better quality.  


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.


Author(s):  
А.Э. Хумала ◽  
М.Ю. Мандельштам ◽  
Н.Б. Никитский ◽  
А.В. Полевой

Мертвая древесина является основным местообитанием для огромного числа лесных видов насекомых, которые используют ее как пищу, субстрат для развития или временное убежище, одновременно участвуя в ее разложении. Видовой состав комплекса насекомых-разрушителей древесины в бореальной зоне довольно хорошо изучен, но до сих пор значительная часть типичных лесных групп представлена видами, биология и пищевая специализация которых изучены недостаточно. В 2015 г. нами исследована фауна насекомых на валеже текущего года трех пород деревьев: береза (Betula pendula), осина (Populus tremula) и ель (Picea abies x fennica). Исследования проводились в заповеднике «Кивач» (Республика Карелия) с использованием специализированных ловушек – стволовых эклекторов. В сборах идентифицировано 107 видов насекомых из 34 семейств отрядов Coleoptera, Hymenoptera и Diptera. Видовое разнообразие сильно варьировало на различных стволах, не зависело от породы и типа отпада (ветровал/бурелом), но имело тенденцию к росту с увеличением диаметра ствола. Видовой состав был довольно специфичен на всех породах, но достоверно отличался только на ели. Анализ распределения видов насекомых на стволах выявил несколько их ассоциаций как на березе, так и на ели, что позволяет говорить о совместной встречаемости некоторых видов (не связанных друг с другом прямыми трофическими связями), а возможно и о существовании более тесных связей между ними. Отмечен ряд видов, редко встречающихся в Фенноскандии, а также ранее не регистрировавшихся в Карелии. Приводится список видов, для которых удалось выявить не известные ранее особенности биологии, а также видов, находки которых интересны в фаунистическом плане. Dead wood is the main habitat for a large number of forest-dwelling insects that use it as a food source, development substrate, or temporary shelter, simultaneously contributing to its disintegration. Species composition of wood-inhabiting insects is well studied in the boreal zone, however a significant part of the typical forest-living groups is represented by species with poorly studied biology and trophic relationships. In 2015, we studied insect fauna on freshly fallen trees of birch (Betula pendula), aspen (Populus tremula) and spruce (Picea abies x fennica). The studies were conducted in the Nature Reserve Kivach (Republic of Karelia) using specially designed trunk emergence traps. Altogether, 107 species, representing 34 families of Coleoptera, Hymenoptera and Diptera were identified. Species diversity varied significantly on different trunks. It did not depend on the tree species or a type of strap (windfall/windbreak), but tended to increase with increasing trunk diameter. The species composition of insects was quite distinctive on different tree species, but differed significantly only on spruce. Analysis of the species distribution revealed several associations on birch and spruce, which suggests at least co-occurrence of some insect species (not assuming direct trophic link) and possibly existence of a closer relationships between them. The range remarkable of species has been observed, including rare representatives of Fennoscandian fauna and species not registered before in the Republic of Karelia. We provide a selective list of species with notes on previously unknown ecological peculiarities, as well as species that represent valuable faunistic findings.


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