Effect of Planting Density on Knot Attributes and Branch Occlusion of Betula alnoides under Natural Pruning in  Southern China

Chun-sheng, Wang; Zhong, Zhao; Hein, Sebastian; Zeng, Jing; Schuler, Johanna; Guo, Junjie; Wen-fu, Guo; Zeng, Jie

doi:10.3390/f6041343

Cited by 22 publications

(16 citation statements)

References 34 publications

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“…5), reducing branch diameter and accelerating stem growth rate appear to be essential for shortening branch occlusion time, especially in natural pruning. It is widely known that branch diameter is closely correlated with planting density (Mäkinen, 2002;Kearney et al, 2007;Hein et al, 2008;Newton et al, 2012;Wang et al, 2015), and that stem diameter growth rate could be accelerated by thinning unwanted competitors and fertilizing the pruned trees (Wiseman et al, 2009;Forrester et al, 2012). Therefore, combining artificial pruning with these measures might further shorten branch occlusion time and rotation length for clear-wood production.…”

Section: Branch Occlusion Timementioning

confidence: 97%

“…Reducing dead knot-related defects has been an important issue in the production of highquality timber. A number of studies have shown that the size of dead knot under natural pruning was significantly and positively correlated with branch diameter and stem diameter growth (Hein and Spiecker, 2007;Hein, 2008;Wang et al, 2015). The incidence and size of decay or discoloration also increased with increasing branch diameter (Gerrand et al, 1997;Wardlaw and Neilsen, 1999;Wiseman et al, 2006;Sandi et al, 2012), dead branch stub length and branch occlusion time (Metzler, 1997;Dȃnescu et al, 2015).…”

Section: Introductionmentioning

confidence: 93%

“…These results suggested that increasing the branch insertion angle and reducing the proportion of acute branches (<30°) could be beneficial in reducing the size of dead knot and discoloration. Because branch insertion angle is usually negatively correlated with branch diameter (Hein, 2008;Wang et al, 2015), and genetic factors tend to play a more important role than the external environment, mitigating acute branch insertion angles should become an important priority in tree breeding. Genetic improvement strategies should be combined with silvicultural methods such as appropriate stocking density for the production of high-quality timber.…”

Section: Branch Insertion Anglementioning

confidence: 99%

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Branch occlusion and discoloration of Betula alnoides under artificial and natural pruning

Chun-sheng

Hein

Zhao

et al. 2016

Forest Ecology and Management

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Section: Branch Occlusion Timementioning

confidence: 97%

Section: Introductionmentioning

confidence: 93%

Section: Branch Insertion Anglementioning

confidence: 99%

See 1 more Smart Citation

Branch occlusion and discoloration of Betula alnoides under artificial and natural pruning

Chun-sheng

Hein

Zhao

et al. 2016

Forest Ecology and Management

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“…Along with the pruned branch stub length and radial growth of the tree, the diameter of a pruned branch is an important factor influencing the time needed for the occlusion of a knot independent of the tree species (Verkasalo and Rintala 1998;DeBell et al 2006;Kannisto and Heräjärvi 2006;Hein and Spiecker 2007;Hein 2008;Dănescu et al 2015;Wang et al 2015Wang et al , 2016Sheppard et al 2016;Stener et al 2017). According to our study, approximately 70-80% of the diameter of an average knot stub was covered in birch trees with the average growth rate in five to six years.…”

Section: Occlusion Rate Of Study Knotsmentioning

confidence: 99%

Effect of pruning season and tool on knot occlusion and stem discolouration in <i>Betula pendula</i> – situation five years after pruning

Niemistö¹,

Kilpeläinen²,

Heräjärvi³

2019

Silva Fenn.

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Effect of pruning season and tool on knot occlusion and stem discolouration in Betula pendula -situation five years after pruningNiemistö P., Kilpeläinen H., Heräjärvi H. (2019). Effect of pruning season and tool on knot occlusion and stem discolouration in Betula pendula -situation five years after pruning. Silva Fennica vol. 53 no. Highlights• The occlusion was the fastest in the case of small living branches of fast growing trees pruned in springtime. • Occlusion was quicker after saw pruning than after secateurs pruning, due to shorter knot stubs.• Branches that were pruned in living state occluded faster than the ones pruned as dead.• Dead branches hit down with a stick occluded slowly. AbstractThis paper investigates and models the effects of pruning season and tool on wound occlusion with varying tree and branch characteristics of silver birch (Betula pendula Roth) stems at the pruning height of 0−4 metres. Dates of eight secateurs prunings, three saw prunings and two sticks prunings as well as unpruned control were tested in permanent plots on four sites. Knot occlusion and discolouration in stemwood were measured from about 1600 studied knots of 112 sample trees felled five to six years after pruning in 2010. Knot occlusion rate was modelled according to pruning tool, date, tree growth, and branch characteristics. The occlusion was the fastest in trees pruned in spring or early summer, and the slowest in trees pruned in autumn. Stubs of living branches occluded faster than the dead ones with the same diameter. Saw pruning resulted in clearly better occlusion rates than secateurs pruning, caused by the shorter knot stubs after saw pruning. Hitting dead branches away with a stick resulted in the worst occlusion status. The colour defects spread more often upward from the knot than downward. Discolouration in stemwood was detected more frequently near to the pruned branches than the unpruned ones, and more widely near to the stubs of dead branches than the living ones. Most saw and secateurs pruned branches were completely occluded during the experiment, so these prunings were suitable for all branches under 20 mm in diameter, and for living branches even up to 30 mm in fast-growing trees.

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“…This has also been demonstrated for a large quantity of species with a specific focus on branch and knot development [4,[7][8][9][10]. For artificial commercial forests, producing high quality wood should also be economically viable.…”

Section: Introductionmentioning

confidence: 99%

Branch Development of Five-Year-Old Betula alnoides Plantations in Response to Planting Density

Chun-sheng

Cheng

Hein

et al. 2018

Forests

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Branch development in the lower part of stem is critical to both early stem growth and wood quality of the most valuable section of tree, and its regulation through planting density has always been greatly concerned. Here the effect of planting density on branch development was examined in a five-year-old plantation of Betula alnoides with six planting densities (625, 833, 1111, 1250, 1667, and 2500 stems per hectare (sph)) in Guangdong Province, South China. Branch quantity (number, proportion, and density), morphology (diameter, length, and angle), position (height and orientation), and branch status (dead or alive) were investigated for 54 dominant or co-dominant trees under six treatments of planting density after the growth of each tree was measured. Factors influencing branch development were also explored by mixed modelling. The results showed that the mean tree heights of 1250 and 1667 sph treatments were higher than those of other planting density treatments. The quantity of live branches decreased with increasing planting density. However, planting density had no significant effect on the number of all branches, and there existed no remarkable difference in branch number and proportion among four orientations. As for branch morphology, only the largest branch diameter had a significantly negative correlation with planting density. In addition, high planting density significantly increased the height of the largest branch within the crown. Mixed effects models indicated that branch diameter, length, and angle were closely correlated with each other, and they were all in positively significant correlation to the branch height at the stem section below six meters. It was concluded that properly increasing planting density will promote natural pruning, improve early branch control, and be beneficial for wood production from the most valuable section of the stem.

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Effect of Planting Density on Knot Attributes and Branch Occlusion of Betula alnoides under Natural Pruning in Southern China

Cited by 22 publications

References 34 publications

Branch occlusion and discoloration of Betula alnoides under artificial and natural pruning

Branch occlusion and discoloration of Betula alnoides under artificial and natural pruning

Effect of pruning season and tool on knot occlusion and stem discolouration in <i>Betula pendula</i> – situation five years after pruning

Branch Development of Five-Year-Old Betula alnoides Plantations in Response to Planting Density

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