Effect of regeneration method on growth, wood density and fibre properties of downy birch (Betula pubescens Ehrh.)

Abstract

Short rotation tree stands, established by coppicing, are nowadays used mainly for energy purposes in Fennoscandia, but their usage for pulp raw material may increase in the future. Downy birch (Betula pubescens), which is commonly used for pulp production in boreal zone, has good sprouting capacity. However, it is not known if the fibre properties of sproutoriginated downy birches differ from those of seed-originated ones. Therefore, fibre length and width of sprout-and seed-originated downy birches grown on fertile soil were measured at a stand age of 25 years. Additionally annual ring width, stem height and diameter, and wood density were studied to compare the growth and wood properties of sprout-and seedoriginated birches. Annual rings were slightly wider in sprout-than in seed-originated birches, whereas no differences were observed in wood density. Fibres, too, were slightly longer and wider in sprout-than in seed-originated trees. Still these minor differences observed here are hardly significant for the industries using birch wood. Consequently downy birch wood from coppiced stands is well suited for pulp. The advantages of coppice, i.e. rapidity and low costs of establishment, productivity, and the ability of downy birch to grow on untypical forest sites, may even increase the importance of the wood coming from coppiced birch stands in the future.

Modeling of radial variations of wood properties in naturally regenerated trees of Betula platyphylla grown in Selenge, Mongolia

“…The mean value of the annual ring width (1.37 mm; Table 1) was similar to those of Betula species grown in Mongolia, Japan [8,9], and Finland [27]. Figure 2 shows the distance from the pith in relation to the annual ring number from the pith.…”

Within-tree and radial variations of wood properties in naturally regenerated trees of Betula platyphylla grown in Nikko, Japan

“…Their mean values were found to be around 1.50–1.80 mm and 0.75–1.00 mm for Betula grossa trees grown in Japan (Furukawa et al 1983). In addition, the mean values of fibre length were 0.65 mm for 25-year old B. pubescens (Luostarinen et al 2009) and 1.11–1.17 mm for 45- and 65-year old B. pendula and B. pubescens (Bhat 1980). The fibre length and vessel element length of B. platyphylla in the present study were similar to B. pendula and B. pubescens grown in Finland (Bhat 1980) and relatively shorter than those of B. grossa grown in Japan (Furukawa et al 1983).…”

“…As shown in Table 2, the mean values of fibre length and vessel element length were 1.20 and 0.70 mm. The fibre length and vessel element length of Betula species have been investigated by several researchers (Bhat 1980; Furukawa et al 1983; Luostarinen et al 2009). Their mean values were found to be around 1.50–1.80 mm and 0.75–1.00 mm for Betula grossa trees grown in Japan (Furukawa et al 1983).…”

“…Thus, it is regarded as an important short-rotation forestry species for wood and biomass resource productions in these countries (Zhang 1997; Johnson 2004; Fu et al 2016; Ohsaki et al 2019; Erdene-Ochir et al 2020). The wood from this species is mainly used for producing interior wood products because it has good machinability, is easily finished, and lacks smell (Verkasalo 1990; Luostarinen et al 2009; Viherä-Aarnio and Velling 2017; Dubois et al 2020). For efficient utilisation of the wood from B. platyphylla for additional purposes, the basic wood properties of this species have been investigated by several researchers (Bhat 1980; Zhang 1995, 1997; Fu et al 2016; Viherä-Aarnio and Velling 2017; Ohsaki et al 2019; Dubois et al 2020; Erdene-Ochir et al 2020).…”

Hybridisation, Introgression and Phylogeography of Icelandic Birch

“…In Europe, silver birch (B. pendula) and downy birch (B. pubescens) probably produce the most valuable hardwood timber for the northern regions of Europe, including Scandinavia, Finland, Russia and the Baltic countries. Recent studies on these species include modelling and analysis of the growth and structure of forests and plantations (Hynynen et al 2010;Kund et al 2010;Lintunen et al 2011); measuring and managing nutrient availability, retranslocation and fertilization (Mandre et al 2010;Ruuhola et al 2011); regeneration and seedling recruitment (Luostarinen et al 2009;Sanz et al 2011). In North America, paper birch (B. papyrifera), the medium-sized and fast-growing tree that forms pure stands or is otherwise found in mixed hardwood-conifer forests, is the most widely distributed birch species, especially in Canada.…”