The influence of neighbours on the growth of trees. I. The demography of buds in Betula pendula

1987 ◽  
Vol 232 (1266) ◽  
pp. 1-18 ◽  
Keyword(s):  
Betula Pendula ◽  
Local Environment ◽  
Silver Birch ◽  
The Third ◽  
Birch Trees ◽  
One Year ◽  
Lateral Branches ◽  
Branch Size

The growth of primary branches of four-year-old silver birch trees grow­ing close to neighbours was followed over a period of three years. Branches were divided into three groups: those entering closely into each other’s canopy, those growing into zones with no neighbour, and an intermediate category. On each branch the following variables were measured: total number of buds, number of living buds, number of lateral branches, gross and net bud production, and bud mortality. Before the start of the study the trees had been growing without neighbours. There were no significant effects of neighbours after one year of the experiment but by the third year all variables were showing some response. Fewer buds were ‘born’ and a greater proportion died in the areas of the crown most subject to interference from the branches of neighbouring trees and this was reflected in smaller mean branch size in these areas. The age of a branch was also an important factor affecting performance. Significant interactions between branch age and interference zone for the number of living buds, gross and net bud production and bud mortality indicated that the effect of neighbours varied with branch age. The behaviour and fate of a bud appear to be conditioned more by its local environment than by its position on the tree of which it is a part.

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

Forests ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 599
Author(s):  
Héloïse Dubois ◽  
Hugues Claessens ◽  
Gauthier Ligot
Keyword(s):  
Betula Pendula ◽  
Western Europe ◽  
Forest Health ◽  
Silver Birch ◽  
Growth Potential ◽  
Betula Pendula Roth ◽  
Crown Diameter ◽  
Birch Trees ◽  
Timber Tree ◽  
Northeastern France

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.

scholarly journals Surfaces of Silver Birch (<i>Betula pendula</i>) are Sources of Biological Ice Nuclei: <i>In-vivo</i> and <i>In-situ</i> Investigations

2020 ◽  
Author(s):  
Teresa M. Seifried ◽  
Paul Bieber ◽  
Laura Felgitsch ◽  
Julian Vlasich ◽  
Florian Reyzek ◽  
...  
Keyword(s):  
Betula Pendula ◽  
Silver Birch ◽  
Rainfall Events ◽  
Alpine Valley ◽  
Ice Nuclei ◽  
Terrestrial Source ◽  
Birch Trees ◽  
Secondary Wood

Abstract. Silver birch (Betula pendula) are known to contain ice-nucleating macromolecules (INMs) to survive in harsh environments. However, little is known about the release and transport of INMs from birch trees into the atmosphere. In this study, we conducted in-situ and in-vivo investigations on INM from nine birches growing in an alpine valley (Ötztal, Austria). A detailed analysis of drill cores shows that INM concentration increases towards outer layers, reaching its maximum near the surface. Aqueous extracts from the surfaces of leaves, bark, primary wood and secondary wood contained INMs (34/36) with concentrations ranging from 9.9·105 to 1.8·109 INM cm−2. In a field study, we analysed the effect of precipitation on the release of these INMs attached to the surface of the trees. These experiments showed that INMs are splashed and aerosolized into the environment during rainfall events, at concentrations and freezing temperatures similar to in-vivo samples. Our work sheds new light on the release and transport of INMs from birch surfaces into the troposphere. Birches growing in boreal and alpine forests should be considered as an important terrestrial source of INMs.

scholarly journals Interactions between Phytophthora cactorum, Armillaria gallica and Betula pendula Seedlings Subjected to Defoliation

2020 ◽  
Author(s):  
Justyna Anna Nowakowska ◽  
Marcin Stocki ◽  
Natalia Stocka ◽  
Sławomir Ślusarski ◽  
Miłosz Tkaczyk ◽  
...  
Keyword(s):  
Betula Pendula ◽  
Systemic Acquired Resistance ◽  
Acquired Resistance ◽  
Chemical Compounds ◽  
Silver Birch ◽  
Fluorescence Measurement ◽  
Phytophthora Cactorum ◽  
Volatile Organic ◽  
Armillaria Gallica ◽  
One Year

The purpose of this study was to better understand the interactive impact of two soil-borne pathogens, Phytophthora cactorum (as the primary pathogen) and Armillaria gallica (as secondary), on two-year-old seedlings of silver birch (Betula pendula) subjected to stress caused by mechanical defoliation simulating primary insect feeding. One year after treatments, the chlorophyll fluorescence measurement and gas chromatography coupled with mass spectrometry (GC-MS) were used to analyze the photosynthetic activity in leaves, the volatile organic compounds (VOCs) emitted by birch leaves and chemical compounds from roots. Only the infection of roots by P. cactorum increased photosynthetic rates in the leaves, which may suggest its cryptic development in contrast to fungi. The birch leaves in seedlings exposed to 50% defoliation, inoculation with P. cactorum and A. gallica emitted more aromatic carbonyls and alcohols, as well as half as much aliphatic esters, compared to untreated controls. In infected birch roots, the production of phenols, triterpenes and fatty alcohols increased, but fatty acids decreased. This was the first experimental confirmation of the pathogenicity of P. cactorum on silver birch seedlings in Poland. The most severe damage to roots took place only in the case of two-way or three-way interactions. Higher levels of aromatic carbonyls and alcohols in leaves, as well as phenolic compounds in roots of stressed birches (compared to control) suggest an activation of plant systemic acquired resistance (SAR).

scholarly journals Surfaces of silver birch (<i>Betula pendula</i>) are sources of biological ice nuclei: in vivo and in situ investigations

2020 ◽  
Vol 17 (22) ◽  
pp. 5655-5667
Author(s):  
Teresa M. Seifried ◽  
Paul Bieber ◽  
Laura Felgitsch ◽  
Julian Vlasich ◽  
Florian Reyzek ◽  
...  
Keyword(s):  
Betula Pendula ◽  
Silver Birch ◽  
Rainfall Events ◽  
Alpine Valley ◽  
Ice Nuclei ◽  
Terrestrial Source ◽  
Birch Trees ◽  
Secondary Wood

Abstract. Silver birch (Betula pendula) is known to contain ice-nucleating macromolecules (INMs) to survive in harsh environments. However, little is known about the release and transport of INMs from birch trees into the atmosphere. In this study, we conducted in situ and in vivo investigations on INMs from nine birches growing in an alpine valley (Ötztal, Austria). A detailed analysis of drill cores showed that INM concentration increases towards outer layers, reaching its maximum near the surface. Aqueous extracts from the surfaces of leaves, bark, primary wood and secondary wood contained INMs (34∕36) with concentrations ranging from 9.9×105 to 1.8×109 INMs cm−2. In a field study, we analysed the effect of precipitation on the release of these INMs attached to the surface of the trees. These experiments showed that INMs are splashed and aerosolized into the environment during rainfall events, at concentrations and freezing temperatures similar to in vivo samples. Our work sheds new light on the release and transport of INMs from birch surfaces into the troposphere. Birches growing in boreal and alpine forests should be considered an important terrestrial source of INMs.

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

Forests ◽  
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.

Health condition and topple problem in silver birch (Betula pendula Roth) in Saint Petersburg

2017 ◽  
Author(s):  
Д.И. Варенцова ◽  
Л.Л. Леонтьев ◽  
Е.Ю. Варенцова
Keyword(s):  
Urban Areas ◽  
Betula Pendula ◽  
Wood Decay ◽  
Sharp Decrease ◽  
Brown Rot ◽  
Health Condition ◽  
Silver Birch ◽  
Saint Petersburg ◽  
Qualitative And Quantitative ◽  
Birch Trees

Приведены результаты изучения фитопатологического состояния березы повислой в насаждениях Санкт-Петербурга, которое в целом оценивается как удовлетворительное с преобладанием ослабленных и сильно ослабленных деревьев. Даны качественная и количественная оценки деревьев-угроз. Проанализированы причины падения деревьев березы в Санкт-Петербурге. Выявлены прямые и косвенные признаки, указывающие на наличие корневых и стволовых гнилей. Сделан вывод, что наиболее часто в городских условиях древесина поражается белой волокнистой и бурой трещиноватой гнилями, возбудителями которых являются дереворазрушающие грибы. При поражении древесины гнилью происходит резкое снижение плотности и прочности, и при значительном ее развитии прочность практически утрачивается. Предел прочности древесины березы с белой волокнистой гнилью III стадии при сжатии вдоль волокон в 6–7 раз, а при статическом изгибе – в 14–16 раз меньше соответствующих показателей неповрежденной древесины. Падение деревьев и их частей часто связано не только с развитием гнили, но и с различными аномалиями в строении древесины, которые приводят к резкому снижению прочности древесины в этих зонах и падению частей дерева. При оценке аварийности деревьев березы следует особое внимание уделять осмотру нижней и средней частей ствола, а при оценке поражения древесины гнилью – не только наличию плодовых тел грибов, но и косвенным признакам – дуплам, сухобокостям, морозным трещинам. The results of the study on phytopathological condition of silver birch trees in St. Petersburg are presented. The condition is assessed generally as satisfactory with a predominance of weak and strongly weakened trees. A qualitative and quantitative assessment of trees that represent topple threat was performed. The reasons for the fall of birch in St. Petersburg were analyzed. Direct and indirect signs indicating the presence of root and stem rots were identified. It was concluded that the most often in urban areas wood is affected by white wood pulp and fissured brown rot caused by wood-destroying fungi. During rotting fungal attacks, sharp decrease in wood density and durability occurs, and with intense rot development durability is almost lost. Comparing to healthy wood, compressive strength of birch wood with white fibrous rot in stage III is 6–7 times lower along the fibers and 14–16 times lower in a static bend. Falling of trees and their parts is often associated not only with the development of rot, but also with various abnormalities in wood structure that lead to a sharp decrease in wood durability in these areas and cause tree parts to fall. In birch trees topple risk assessment special attention should be paid to examination of lower and middle parts of the trunk. In assessment of wood decay extent, not only the presence of fungi fruiting bodies should be considered, but also circumstantial evidence such as hollows, stem scars, and frost cracks.

LIME AND DAIRY PRODUCTION

1982 ◽  
pp. 93-103
Author(s):  
N.A. Thomson
Keyword(s):  
Soil Moisture ◽  
Dairy Cows ◽  
Milk Production ◽  
Soil Ph ◽  
Dairy Production ◽  
Pasture Production ◽  
The Third ◽  
One Year ◽  
Plasma Magnesium

In a four year grazing trial with dairy cows the application of 5000 kg lime/ ha (applied in two applications of 2500 kg/ha in winter of the first two years) significantly increased annual pasture production in two of the four years and dairy production in one year. In three of the four years lime significantly increased pasture growth over summer/autumn with concurrent increases in milk production. In the last year of the trial lime had little effect on pasture growth but a relatively large increase in milkfat production resulted. A higher incidence of grass staggers was recorded on the limed farmlets in spring for each of the four years. In the second spring immediately following the second application of lime significant depressions in both pasture and plasma magnesium levels were recorded. By the third spring differences in plasma magnesium levels were negligible but small depressions in herbage magnesium resulting from lime continued to the end of the trial. Lime significantly raised soil pH, Ca and Mg levels but had no effect on either soil K or P. As pH levels of the unlimed paddocks were low (5.2-5.4) in each autumn and soil moisture levels were increased by liming, these factors may suggest possible causes for the seasonality of the pasture response to lime

Bankruptcy Model Construction and its Limitation in Input Data Quality

2019 ◽  
Vol 10 (2) ◽  
pp. 117-125
Author(s):  
Dana Kubíčková ◽  
◽  
Vladimír Nulíček ◽  
Keyword(s):  
Data Quality ◽  
Normal Distribution ◽  
Input Data ◽  
Model Construction ◽  
The Third ◽  
Third Stage ◽  
Discriminant Analyses ◽  
One Year ◽  
The University ◽  
Multivariate Discriminant

The aim of the research project solved at the University of Finance and administration is to construct a new bankruptcy model. The intention is to use data of the firms that have to cease their activities due to bankruptcy. The most common method for bankruptcy model construction is multivariate discriminant analyses (MDA). It allows to derive the indicators most sensitive to the future companies’ failure as a parts of the bankruptcy model. One of the assumptions for using the MDA method and reassuring the reliable results is the normal distribution and independence of the input data. The results of verification of this assumption as the third stage of the project are presented in this article. We have revealed that this assumption is met only in a few selected indicators. Better results were achieved in the indicators in the set of prosperous companies and one year prior the failure. The selected indicators intended for the bankruptcy model construction thus cannot be considered as suitable for using the MDA method.

The Return of N’Guyen Van Binh

2020 ◽  
Vol 46 (2) ◽  
pp. 25-42
Author(s):  
Geoff Read
Keyword(s):  
Third Republic ◽  
Forced Labor ◽  
Political Prisoner ◽  
Second Empire ◽  
Indentured Servitude ◽  
The Third ◽  
Original Sentence ◽  
French Colonial ◽  
One Year

This article explores the case of N’Guyen Van Binh, a South Vietnamese political prisoner exiled for his alleged role in “Poukhombo’s Rebellion” in Cambodia in 1866. Although Van Binh’s original sentence of exile was reduced to one year in prison he was nonetheless deported and disappeared into the maw of the colonial systems of indentured servitude and forced labor; he likely did not survive the experience. He was thus the victim of injustice and his case reveals the at best haphazard workings of the French colonial bureaucracy during the period of transition from the Second Empire to the Third Republic. While the documentary record is entirely from the perspective of the colonizers, reading between the lines we can also learn something about Van Binh himself including his fierce will to resist his colonial oppressors.

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