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Showing 1 to 20 of 67 for “"betula"”.
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Morphometric discrimination among Betula nana, Betula pubescens and their hybrids using the shapeR package
Downy birch (Betula pubescens) and dwarf birch (Betula nana) are natural woody species in Iceland and play important roles in the terrestrial ecosystems. They both belong to the same genus and can hybridize. Since downy birch is tetraploid and dwarf birch is diploid, their hybrids become triploid. …
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Útbreiðsla birkis (Betula pubescens) í Bæjarstaðarskógi
Bæjarstaðarskógur er náttúrlegur birkiskógur staðsetur á Suðausturlandi. Hann er einstakur á Íslandi þar sem beint, hávaxið birki vex þar í miklu magni, sem er sjaldgæft í íslenskum birkiskógum. Skógurinn hefur verið friðaður síðan árið 1935 og var þá girtur af til að vernda hann gegn beit. Eftir …
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In vitro propagation of Betula uber (Ashe) Fernald
Dormant bud and actively growing shoot tip explants of B. uber were cultured on Murashige & Skoog (MS) and modified woody plant (WPM) basal salts supplemented with organic nutrients and benzylaminopurine (BAP). Shoot tip explants were morphogenically more responsive than dormant bud explants. The …
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Áhrif birkihnúðmýs (Semudobia betulae Winn.) á frægæði birkis (Betula pubescens Ehrh.)
Birkiskógar eru eitt mikilvægasta vistkerfi í íslenskri náttúru og hefur djúpar rætur í vitund þjóðarinnar. Frá landnámi hefur birkiskógum hnignað verulega og er núverandi þekja þeirra einungis brot af því sem hún er talin hafa verið þá. Mikilvægt er að varðveita og endurheimta náttúrulega …
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Treeline of mountain birch (Betula pubescens Ehrh.) in Iceland and its relationship to temperature
Die Waldfläche der Moorbirke (Betula pubescens Ehrh.) in Island wurde zwischen der Besiedlung des Landes durch die Wikinger ab 874 n. Chr. und heute dramatisch reduziert. Ursachen des Rückgangs waren v. a. grossflächige Nutzung des Waldes für die Produktion von Holzkohle, Verbiss durch frei …
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The influence of plant size and fertilization on catkin production in birch (Betula pubescens Ehrh.)
Downy birch Betula pubescens Ehrh. is the only tall growing native birch species in Iceland. Around the time of the settlement, birch woodlands used to cover large areas of Iceland, but today only little is left. Regeneration of birch is a key process in woodland expansion and is important for land …
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The effect of the growth retardant Paclobutrazol on the in vitro growth and development of Betula and Populus species
… (PBZ) to in vitro cultures of Populus and Betula species was studied, with a view to translating the effect into the field, and ultimately to control undesired tree growth commercially. Plant growth and associated regulatory effects were studied under controlled conditions over an eight to …
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A study on above- and belowground biomass and carbon stocks as well as sequestration of mountain birch (Betula pubescens Ehrh.) along a chronosequence in southern Iceland
Following a period of land degradation lasting more than one thousand years, Iceland has undertaken ambitious restoration and afforestation efforts for one century now. Afforestation has also been a central venture of the Icelandic government in order to meet the commitments assigned by the Kyoto …
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The effects of age and size of canopy gaps on the mycorrhizae of yellow birch (Betula alleghaniensis Britton) and sugar maple (Acer sacchrum Marsh.) from deciduous forests of the Québec city region
Effects of different sized and different aged canopy gaps on the ectomycorrhizae of yellow birch and vesicular-arbuscular mycorrhizae of sugar maples collected from two deciduous forests in central Quebec were examined. The colonization of maple roots by arbuscules, vesicles, and coils were …
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Watershed and Streamside Management Zone Characterization in the Allegheny Plateau of West Virginia
… tulipifera, Fagus grandifolia, Tilia americana, Betula lenta, snags, Betula lutea, Fraxinus spp., and Acer rubrum. The overall average streamwater temperature is 13°C. Highest daily temperature occurred in the mid-afternoon and lowest temperatures occurred just before sunrise. Streamwater quality …
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Development of soil lead and tree-ring methods for characterizing atmospheric deposition gradients and subsequent tree growth responses
… (Picea rubens, Liriodendron tulipifera, and Betula alleghaniensis) along spatial gradients of deposition within the eastern United States. By studying tree-rings along the gradient, I was able to examine the inherently long-term and cumulative effects of deposition on tree growth and how this …
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The summer fleshy fungus flora of the Gorge of Carp Creek, University of Michigan Biological Station, with a comparison of the years 1961 and 1962
… the greatest number of species. Pieca-Thuga bog, Betula forest, and Alnus-Typha swamp produced the next larer number of species respectively.
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Changes in stand structure and species diversity following clearcutting in central Appalachian hardwoods
… Species such as Liriodendron tulipifera, Betula lenta , and Robinia pseudoacacia increased in importance in the postharvest stands, whereas Quercus rubra, Carya spp., and Fagus grandifolia decreased. The overstory of the future stand will be dominated by Liriodendron tulipifera and Tilia …
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The Life and Times of Medieval Drifters: The Social and Environmental Significance of Driftwood in the Medieval Icelandic Culture and Identity, 9th - 13th Centuries
… in the late ninth century, low-growing birch ( Betula sp.), the island's only natural growing wood source, was drastically depleted for agricultural land, leaving the early settlers with limited options for a wood resource. Following this, the naturally occurring driftwood on Iceland's arctic …
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On-line screening of bioactive compounds and application of comprehensive two-dimensional gas chromatography-time-of-flight mass spectrometry for the analysis of birch bark
… for chemical composition of birch bark (Betula pendula). The exploitation of the mass spectra and retention index information allowed the identification of more than 600 organic compounds. Altogether, 59 phenolic compounds were identified in the inner layer of birch bark. To the best of …
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Latitudinální proměna ideálního stromu podle metabolické teorie
… these and also other questions using 75 Betula spp. trees on 25 sites of a latitudinal gradient (mostly in Sweden). There is a lot of studies trying to adress similar questions by working in a framework of metabolic theory of ecology. Considering diameter-height relationship scaling …
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Species, stand, and regional response to forest damage in southwestern Quebec following the 1998 ice storm
… Acer rubrum L., Populus tremuloides Michx., and Betula populifolia Marsh. to ice storm damage was studied in the Northern Hardwood Forest of southwestern Quebec, Canada. The focus of the study was the analysis of tree damage resulting from ice accumulation ranging from 2 to 88 millimeters radial …
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The relationship between stem-form, stand-closure and site -conditions : the influence of environmental conditions on tree allometry and forest structure in west-central Alberta
… lasiocarpa, Larix laricina, Populus tremuloides, Betula papyrifera and Populus balsamifera plus a comprehensive all-species data set. As the actual conformation of the stern is very individual, stem-fo~was represented by the diameter at breast height to total height r~tio. The four stand-closure …
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