scholarly journals Phenological pattern of leaf-fall phenophase in Quercus robur L. populations of the Belgrade area

2016 ◽  
pp. 9-28
Author(s):  
Branislava Batos ◽  
Sasa Orlovic ◽  
Jelena Ninic-Todorovic ◽  
Darka Seslija-Jovanovic ◽  
Danijela Miljkovic
Keyword(s):  
Quercus Robur ◽  
Genetic Factors ◽  
Climatic Factors ◽  
Pedunculate Oak ◽  
Leaf Fall ◽  
Significance Level ◽  
The Common ◽  
Common Oak ◽  
Two Populations ◽  
Made In

Our study of phenological variability in the common oak (Quercus robur L.) was mainly focused on the analysis of the leaf-fall phenophase. The observations were made in two populations in the area of Belgrade (Serbia). We observed 29 trees in each site, during three consecutive years. According to the results of a nonparametric analysis of Mann-Whitney U test we found differences in the leaf fall phenophase (the start, the length and the end) among the populations: statistically significant differences were verified for the start and the length of the leaf fall in two of three observed years, and for the end of leaf fall in one observed year. The differences in the leaf fall within each population among the observed years were verified by the F-test at the significance level of P < 0.05: statistically significant differences were found for the start of leaf fall in ?Ada Ciganlija? population, and for the length and the end of leaf fall in both populations. According to the phenological pattern of population 31% of trees in ?Ada Ciganlija? population and 24.1% of trees in ?Bojcin forest? population did not change its phenological group in relation to the start of the leaf fall (?early?, ?average? and ?late?) during three years of observation. Since the phenological traits are under significant influence of both environmental and genetic factors, it is very important to evaluate those factors according to tree differentiation to phenological groups for pedunculate oak selection. An overview of the pattern of leaf fall phenology and the response to the changing climatic factors will help in understanding the leaf fall phenology at the level of an individual and at the level of species.

scholarly journals Polycyclism and phenological variability in the common oak (Quercus robur L.)

2012 ◽  
Vol 64 (1) ◽  
pp. 97-105 ◽  
Author(s):  
M. Bobinac ◽  
Branislava Batos ◽  
Danijela Miljkovic ◽  
Stojanka Radulovic
Keyword(s):  
Comparative Research ◽  
Quercus Robur ◽  
Growing Season ◽  
Leaf Fall ◽  
Oak Trees ◽  
Starting Point ◽  
The Common ◽  
Leaf Flush ◽  
Control Tree ◽  
Common Oak

Polycyclism is the ability for a plant to produce several flushes in the same growing season. The rare phenomenon of common oak (Quercus robur L.) summer flowering is proof of complex polycyclism. Common oak summer flowering and the unusual transformation of inflorescences were the starting point for this study of the phenological variability of common oak trees in identical site conditions. This paper presents comparative research of leaf flushing, flowering, and leaf fall phenophases in a common oak with summer flowering and a control tree in which this phenomenon was not observed. Both trees displayed frequent polycyclism (polyphase formation of annual shoots during the growing season), but with different intensities depending on the trees and the years. Compared to the control tree, the tree with summer flowering was characterized by a later onset of leaf-flush phenophase and leaf fall phenophase and a longer retention of the leaves in the crown.

The resistance of the phenological forms of the common oak (Quercus robur L.) to unfavorable external factors

2017 ◽  
Author(s):  
И.А. Уткина ◽  
В.В. Рубцов
Keyword(s):  
Quercus Robur ◽  
Insect Pests ◽  
Weather Conditions ◽  
External Factors ◽  
Individual Species ◽  
Early Form ◽  
The Common ◽  
Spring Frosts ◽  
Common Oak ◽  
Late Form

Ранняя (Quercus robur var. praecox Czern.) и поздняя (Q. robur var. tardiflora Czern.) фенологические формы дуба черешчатого, выделенные в самостоятельные таксоны в середине XIX в., неоднократно становились объектами исследований для специалистов разного профиля. Собрано немало данных о различиях в их росте, требованиях к условиям местообитания, устойчивости к неблагоприятным внешним факторам. Иногда кроме ранней и поздней феноформ выделяют еще и промежуточные между ними. Наиболее отчетливо различия между феноформами, обусловленные разными сроками листораспускания, проявляются в реакции на поздние весенние заморозки и повреждение листвы насекомыми-филлофагами. Так как на деревьях поздней формы листовые и цветочные почки раскрываются намного позже, чем на ранней, поздняя форма избегает повреждения весенними заморозками. Кроме того, обладая меньшей способностью к формированию летних побегов, она меньше повреждается и ранними осенними заморозками, а также зимними морозами, что способствует образованию у нее более прямых и полнодревесных стволов, по сравнению с ранней формой. Ранняя форма чаще и сильнее повреждается филлофагами ранневесеннего комплекса, у которых отрождение гусениц из яиц синхронизировано с раскрытием почек и распусканием листьев. Есть данные, что видовой состав вредителей листвы на деревьях ранней и поздней форм дуба при их совместном произрастании примерно одинаков, зато численность отдельных видов филлофагов и их соотношение различны. На деревьях ранней формы их больше в несколько раз, что объясняется совпадением фаз развития большинства ранневесенних видов филлофагов и листвы этой формы дуба. Согласно результатам проведенных исследований, поздняя форма предпочтительнее для создания лесных культур дуба как более устойчивая к неблагоприятным погодным условиям и насекомым-вредителям. Early (Quercus robur var. praecox Czern.) and late (Q. robur var. tardiflora Czern.) phenological forms of the common oak, recognized as independent taxa in the mid-nineteenth century, have been subjects of multiple studies by specialists of different fields. Abundant data on the differences in their growth requirements, habitat conditions, and resistance to unfavorable external factors have been collected. Some specialists in addition to early and late phenoforms distinguish intermediate forms. Most clearly the differences between these forms appear in response to late spring frosts and damage of leaves by phyllophagous insects due to different timing of the forms' leafing. As leaf and flower buds in late oaks are revealed much later than in early oaks, late form avoids damage by spring frosts. In addition, due to lower ability to form summer shoots, late oaks are less damaged by early autumn frosts and winter freeze, which contributes to the formation of more straight and full trunks comparing to early oaks. Early oaks are damaged more severely by phyllophagous insects of spring complex, in which hatching of caterpillars from eggs is synchronized with opening buds and unfolding of leaves. There is evidence that species composition of foliage pests on co-occurant early and late forms of oak is nearly the same, but the number of individual species of phyllophagous insects and their ratio are different. In the early form the number of phyllophagous insects is greater by several fold due to concurrence of developmental phases in most early spring phyllophagous species and foliage of this oak form. The obtained results show that the late form of common oak is preferable for forest plantations as more resistant to unfavorable weather conditions and insect pests.

scholarly journals Comparing densities of spider mites (Tetranychidae) and predatory mites (Phytoseiidae) on the common oak (Quercus robur L.) in forests of natural and industrial areas

2016 ◽  
Vol 77 (3) ◽  
pp. 177-185
Author(s):  
Magdalena Lubiarz
Keyword(s):  
National Park ◽  
Quercus Robur ◽  
Spider Mite ◽  
Predatory Mites ◽  
Spider Mites ◽  
Predatory Mite ◽  
The Common ◽  
Common Oak ◽  
The Town ◽  
Mite Family

Abstract This paper presents results of studies conducted in the forest areas of the Polesie National Park and in the surroundings of the chemical producer Zakłady Azotowe in the town of Puławy on the abundance of mites from the families Tetranychidae and Phytoseiidae. These studies were conducted on eight different sites in the years 2002–2004 and aimed at answering the question of whether mite abundance is related to factors such as area, site and year. In total, 8894 specimen of the spider mite family and 1835 specimen of the predatory mite family were collected. Spider mites were more abundant in Puławy than in the Polesie National Park, whilst the abundances of predatory mites were similar in both study areas. For spider mites, statistically significant differences were found in terms of study area and site, but also in terms of the study area in relation to the year of investigation. In the case of predatory mites, statistically significant differences were also found in terms of the study area in relation to the year of investigation.

An Overview of Dementias

2012 ◽  
Vol 21 (3) ◽  
pp. 75-84
Author(s):  
Venkata Vijaya K. Dalai ◽  
Jason E. Childress ◽  
Paul E Schulz
Keyword(s):  
Clinical Presentation ◽  
Treatment Options ◽  
Current Treatment ◽  
Great Variability ◽  
Health Concern ◽  
Public Health Concern ◽  
Life Threatening ◽  
The Common ◽  
Neurodegenerative Dementias ◽  
Made In

Dementia is a major public health concern that afflicts an estimated 24.3 million people worldwide. Great strides are being made in order to better diagnose, prevent, and treat these disorders. Dementia is associated with multiple complications, some of which can be life-threatening, such as dysphagia. There is great variability between dementias in terms of when dysphagia and other swallowing disorders occur. In order to prepare the reader for the other articles in this publication discussing swallowing issues in depth, the authors of this article will provide a brief overview of the prevalence, risk factors, pathogenesis, clinical presentation, diagnosis, current treatment options, and implications for eating for the common forms of neurodegenerative dementias.

Cuckoo chicks evicting their nest mates: coincidental observations by Edward Jenner in England and Antoine Joseph Lottinger in France

2011 ◽  
Vol 38 (2) ◽  
pp. 220-228 ◽  
Author(s):  
Spencer G. Sealy ◽  
Mélanie F. Guigueno
Keyword(s):  
Royal Society ◽  
Cuculus Canorus ◽  
Common Cuckoo ◽  
Cuckoo Chick ◽  
The Common ◽  
Made In ◽  
Royal Society Of London

For centuries, naturalists were aware that soon after hatching the common cuckoo (Cuculus canorus) chick became the sole occupant of the fosterer's nest. Most naturalists thought the adult cuckoo returned to the nest and removed or ate the fosterer's eggs and young, or the cuckoo chick crowded its nest mates out of the nest. Edward Jenner published the first description of cuckoo chicks evicting eggs and young over the side of the nest. Jenner's observations, made in England in 1786 and 1787, were published by the Royal Society of London in 1788. Four years before Jenner's observations, in 1782, Antoine Joseph Lottinger recorded eviction behaviour in France and published his observations in Histoire du coucou d'Europe, in 1795. The importance of Lottinger's and Jenner's observations is considered together.

Potenzielle Eichenwuchsgebiete und aktuelle Eichenmischwälder der Schweiz | Potential oak sites and actual mixed oak forests in Switzerland

2008 ◽  
Vol 159 (5) ◽  
pp. 103-111
Author(s):  
Urs Mühlethaler ◽  
Yvonne Reisner ◽  
Nele Rogiers
Keyword(s):  
Information System ◽  
Quercus Robur ◽  
Geographical Information ◽  
Oak Forests ◽  
Natural Growth ◽  
Growth Area ◽  
Entire Country ◽  
Middle Spotted Woodpecker ◽  
Evaluation Matrix ◽  
Common Oak

On behalf of the Federal Office for the Environment (FOEN), the Swiss College for Agriculture established the basis to foster oak species in Switzerland. For this, the growth areas of three oak species, common oak (Quercus robur), sessile oak (Q. petraea) and pubescent oak (Q. pubescens) were assessed throughout the entire country. The assessment was based on their physiological potential, their natural growth area and on the appearance of the middle spotted woodpecker. In addition, the older mixed oak stands were surveyed. These fundamental data were collected with a geographical information system and analyzed for each canton. Altogether, approximately one-fourth of the Swiss forest area is suitable for oak. The natural oak growth area covers however 38 500 ha only. About 19 000 ha of forest are populated by the middle spotted woodpecker and extended older mixed oak forests are found on approximately 24 500 ha. According to the applied evaluation matrix, the greatest potential for fostering oak species lies in eight cantons: Aargau, Zürich, Solothurn, Thurgau, Vaud, BaselLandschaft, Ticino and Schaffhausen.

Growth and management of mixed Pinus sylvestris - Quercus robur stands in Flanders, Belgium

1993 ◽  
Vol 58 ◽  
Author(s):  
D. Maddelein ◽  
J. Neirynck ◽  
G. Sioen
Keyword(s):  
Pinus Sylvestris ◽  
Natural Regeneration ◽  
Quercus Robur ◽  
Good Growth ◽  
Pedunculate Oak ◽  
Selection System ◽  
Management Options ◽  
Stand Management ◽  
Pine Stands

Mature  Scots pine (Pinus sylvestris  L.) stands are dominating large parts of the Flemish forest area. Broadleaved  species regenerate spontaneously under this pine canopy. This study studied  the growth and development of two planted pine stands with an older natural  regeneration, dominated by pedunculate oak (Quercus  robur L.), and discussed management options for  similar stands.     The results indicated a rather good growth of the stands, with current  annual increments of 5 m3.ha-1.yr-1. The pine overstorey is growing into valuable sawwood  dimensions, while the broadleaved understorey slowly grows into the  upperstorey. The quality of the regeneration is moderate but can be improved  by silvicultural measurements (pruning, early selection).     In both stands, an interesting (timber production, nature conservation)  admixture of secondary tree species is present in the regeneration. Stand  management is evolving from the classical clearcut system towards a  combination of a type of selection and group selection system.

GENETIC FACTORS INFLUENCING THE COMMON NEUROBIOLOGICAL SUBSTRATE FOR MENTAL DISORDERS

2019 ◽  
Vol 29 ◽  
pp. S798
Author(s):  
Till Andlauer ◽  
Thomas Mühleisen ◽  
Felix Hoffstaedter ◽  
Alexander Teumer ◽  
Anja Teuber ◽  
...  
Keyword(s):  
Mental Disorders ◽  
Genetic Factors ◽  
Factors Influencing ◽  
The Common

Static pressure distribution in the free turbulent jet

1957 ◽  
Vol 3 (1) ◽  
pp. 1-16 ◽  
Author(s):  
David R. Miller ◽  
Edward W. Comings
Keyword(s):  
Static Pressure ◽  
Longitudinal Velocity ◽  
Fluid Motion ◽  
Mean Velocity ◽  
Free Jet ◽  
Static Pressure Distribution ◽  
Two Dimensional Flow ◽  
The Common ◽  
Jet Theory ◽  
Made In

Measurements of mean velocity, turbulent stress and static pressure were made in the mixing region of a jet of air issuing from a slot nozzle into still air. The velocity was low and the two-dimensional flow was effectively incompressible. The results are examined in terms of the unsimplified equations of fluid motion, and comparisons are drawn with the common assumptions and simplifications of free jet theory. Appreciable deviations from isobaric conditions exist and the deviations are closely related to the local turbulent stresses. Negative static pressures were encountered everywhere in the mixing field except in the potential wedge region immediately adjacent to the nozzle. Lateral profiles of mean longitudinal velocity conformed closely to an error curve at all stations further than 7 slot widths from the nozzle mouth. An asymptotic approach to complete self-preservation of the flow was observed.

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