Towards Silviculture Guidelines to Produce Large-Sized Silver Birch (Betula pendula Roth) Logs in Western Europe

Forest health problems arising from climate change, pests and pathogens are a threat to the main timber tree species. As a result, silver birch (Betula pendula Roth) has become a precious asset for meeting oncoming forestry challenges in western Europe. However, silviculture guidelines to produce high-value birch logs in this region are lacking. Producing large-sized birch trunks requires crown release, i.e., removing crown competitors around selected target trees. These interventions are currently seldom carried out or else too late when the growth potential of the trees has already diminished. This study set out to ascertain the diameter at breast height (dbh) that could be reached by crown-released birch, determine dbh-associated crown diameters, and further characterize the gain obtained from early crown release on birch dbh growth. We measured 704 birch trees that had undergone crown release in 38 naturally regenerated pure birch stands in southern Belgium and in northeastern France. We then evaluated the variation in stem and crown diameter, and analyzed increments in response to the earliness of the interventions in three subsamples, also compared with control target birch. We found that trees with a dbh of 50 cm could be grown within 60 years. Based on crown diameter, to produce 40, 50 and 60 cm dbh trunk, the distance required between target birch trees at the end of the rotation was around 8, 10 and 12 m. With no intervention and in ordinary dense birch regenerations, the dbh increment was found to decline once the stand reached age 4–7 years. Starting crown release in stands aged 4–5 years can double the dbh increment of target trees and provide a continual gain that may last up to 20 years. When birch crowns are released after 9–12 years, it may already be too late for them to recover their best growth rate. Our contribution should help complete emerging guidelines in support of birch silviculture development.

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The Quantity and Biochemical Composition of Sap Collected from Silver Birch (Betula pendula Roth) Trees Growing in Different Soils

Forests ◽

10.3390/f11040365 ◽

2020 ◽

Vol 11 (4) ◽

pp. 365

Author(s):

Justas Mingaila ◽

Dovilė Čiuldienė ◽

Pranas Viškelis ◽

Edmundas Bartkevičius ◽

Vladas Vilimas ◽

...

Keyword(s):

Biochemical Composition ◽

Betula Pendula ◽

Silver Birch ◽

Nutrient Contents ◽

Betula Pendula Roth ◽

Market Sector ◽

Birch Trees ◽

Crown Base Height ◽

Mineral Soils ◽

Different Soils

Birch sap is colourless or slightly opalescent and is traditionally drunk in spring. Currently, birch sap is becoming more important in the market sector as well as to pharmacy companies due to its biochemical composition and use in a wide variety of products. To extract good quality sap using birch resources in a sustainable way, there is a need to investigate the influence of the dendrometric parameters of birch trees and soil properties on the quantity and chemical composition of birch sap. This study is performed in five silver birch (Betula pendula Roth) forest stands growing in Histosol, Luvisol and Arenosol with different moisture and nutrient contents. The results indicated that the most productive silver birch trees for sap harvesting were taller than 28 m, had a diameter at breast height over 40 cm and a crown base height greater than 19 m. Additionally, the highest quantity of birch sap was harvested from trees growing in well-aerated mineral soils (Arenosol and Luvisol) with normal moisture content. However, the sweetest birch sap was harvested from trees growing in nutrient-rich organic (undrained peatland Histosol) and temporarily flooded mineral (Luvisol) soils.

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Health condition of silver birch (Betula pendula Roth) in different forest site conditions of the Left-bank Forest Steppe of Ukraine

Известия СПбЛТА ◽

10.21266/2079-4304.2017.220.155-168 ◽

2017 ◽

Author(s):

В.Л. Мешкова ◽

Я.В. Кошеляева

Keyword(s):

Betula Pendula ◽

Forest Health ◽

Health Condition ◽

Silver Birch ◽

Forest Steppe ◽

Forest Site ◽

Left Bank ◽

Site Conditions ◽

Betula Pendula Roth ◽

Birch Tree

Цель исследования – выявить особенности двухлетней динамики показателей санитарного состояния березы повислой (Betula pendula Roth) в различных типах лесорастительных условий Левобережной лесостепи Украины. Проанализированы данные о санитарном состоянии березы повислой, полученные в 2015–2016 гг. на девяти пробных площадях. Три из них представляют свежую суборь (В2), три – свежий сугрудок (С2) и три – свежий груд (D2) (по классификации Алексеева–Погребняка) – наиболее представленные в регионе типы лесорастительных условий. Все насаждения имеют искусственное семенное происхождение и примерно одинаковый возраст (40–45 лет), что соответствует наибольшему представительству в лесном фонде Левобережной лесостепи. Категорию санитарного состояния каждого дерева березы на пробных площадях оценивали в соответствии с Санитарными правилами в лесах Украины. Индекс санитарного состояния насаждений определяли по количеству деревьев и по доле площади поперечного сечения стволов, представленных в каждой категории санитарного состояния. Индекс санитарного состояния отдельно рассчитывали для всех деревьев (II–VI) и для жизнеспособных деревьев I–IV категорий санитарного состояния (II–IV). Значения индексов санитарного состояния анализируемых насаждений, вычисленных с учетом как распределения деревьев, так и их площади поперечного сечения (1,7–2,5), позволяют считать эти березняки ослабленными. Отмечена тенденция ухудшения состояния березы в 2016 г., по сравнению с 2015 г., а также в ряду свежие субори (В2) – свежие сугрудки (С2) – свежие груды (D2). Среднее санитарное состояние ухудшалось преимущественно из-за плохого состояния деревья с меньшим диаметром, т. е. патологические процессы не были выражены в насаждениях в целом. В обследованных насаждениях зафиксированы такие признаки ослабления, как усыхание вершин, наличие водяных побегов, заселение стволовыми насекомыми (входные отверстия, ходы), потеки на стволах. В 2016 г., по сравнению с 2015 г., возросла доля деревьев с признаками бактериальной водянки. The goal of research was to reveal the peculiarities of two-year dynamics of health condition indices for silver birch (Betula pendula Roth) in different types of forest site conditions of the Left-bank Forest Steppe of Ukraine. Presented data on silver birch health condition were obtained from 9 permanent sample plots in 2015–2016. Three plots were located in a fresh subor (fresh relatively poor forest site conditions В2), other three plots in a fresh sugrud (fresh relatively fertile forest site conditions C2), and three more plots in a fresh grud (fresh fertile forest site conditions D2) (by Alekseyev–Pogrebnyak classification). These forest site conditions are the most represented in the region. All studied stands were of artificial seed origin and are about the same age (40–45 years old), which reflects the largest representation in the forests of the Left-bank Forest Steppe of Ukraine. Categories of health condition were assessed for each birch tree in the sample plots according to the «Sanitary rules in the forests of Ukraine». Index of forest health condition was evaluated by a number of trees and by the part of cross-sectional area of birch stems in each category of health condition. Index of forest health condition was calculated separately for all trees (II–VI) and for viable trees of the I–IV categories of health condition (II–IV). All evaluated indices of health condition (1.7–2.5) allow to suggest these birch stands weakened. There is a trend of worsening birch condition in 2016 comparing to 2015 as well as in the series «fresh relatively poor forest site conditions (В2) – fresh relatively fertile forest site conditions (С2) – fresh fertile forest site conditions (D2)». Worsening of health condition was registered mainly in trees with smaller diameter, thus pathological processes were not extensive in the stands as whole. Dieback, epicornic shoots, stem insects' entrance holes and galleries, and sap flux on stems were registered as the signs of stands weakening. In 2016 in comparison to 2015, the performance of wetwood has increased.

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The Effect of Growth Rate on the Strength Properties of Sawn Beams of Silver Birch (Betula pendula Roth)

Scandinavian Journal of Forest Research ◽

10.1080/02827589950152250 ◽

1999 ◽

Vol 14 (1) ◽

pp. 18-26

Author(s):

R. A. Dunham ◽

A. D. Cameron ◽

J. A. Petty

Keyword(s):

Growth Rate ◽

Betula Pendula ◽

Strength Properties ◽

Silver Birch ◽

Betula Pendula Roth

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Evaluation of Antioxidative Mechanisms In Vitro and Triterpenes Composition of Extracts from Silver Birch (Betula pendula Roth) and Black Birch (Betula obscura Kotula) Barks by FT-IR and HPLC-PDA

Molecules ◽

10.3390/molecules26154633 ◽

2021 ◽

Vol 26 (15) ◽

pp. 4633

Author(s):

Aleksandra Ostapiuk ◽

Łukasz Kurach ◽

Maciej Strzemski ◽

Jacek Kurzepa ◽

Anna Hordyjewska

Keyword(s):

Chemical Composition ◽

Betula Pendula ◽

Antioxidant Properties ◽

Silver Birch ◽

Biologically Active Substances ◽

Biologically Active ◽

Outer Bark ◽

Betula Pendula Roth ◽

Production Of Hydrogen ◽

Active Substances

Silver birch, Betula pendula Roth, is one of the most common trees in Europe. Due to its content of many biologically active substances, it has long been used in medicine and cosmetics, unlike the rare black birch, Betula obscura Kotula. The aim of the study was therefore to compare the antioxidant properties of extracts from the inner and outer bark layers of both birch trees towards the L929 line treated with acetaldehyde. Based on the lactate dehydrogenase test and the MTT test, 10 and 25% concentrations of extracts were selected for the antioxidant evaluation. All extracts at tested concentrations reduced the production of hydrogen peroxide, superoxide anion radical, and 25% extract decreased malonic aldehyde formation in acetaldehyde-treated cells. The chemical composition of bark extracts was accessed by IR and HPLC-PDA methods and surprisingly, revealed a high content of betulin and lupeol in the inner bark extract of B. obscura. Furthermore, IR analysis revealed differences in the chemical composition of the outer bark between black and silver birch extracts, indicating that black birch may be a valuable source of numerous biologically active substances. Further experiments are required to evaluate their potential against neuroinflammation, cancer, viral infections, as well as their usefulness in cosmetology.

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