The combined effect of CO2, ozone, and drought on the radical scavenging system of young oak trees (Quercus petraea) — A phytothron study

Chemosphere ◽  
1998 ◽  
Vol 36 (4-5) ◽  
pp. 783-788 ◽  
Author(s):  
C. Kurz ◽  
U. Schmieden ◽  
P. Strobel ◽  
A. Wild
Keyword(s):  
Radical Scavenging ◽  
Quercus Petraea ◽  
Combined Effect ◽  
Oak Trees

Influence de la densité du couvert forestier sur le développement architectural de jeunes chênes sessiles, Quercus petraea (Matt.) Liebl. (Fagaceae), en régénération forestière

2000 ◽  
Vol 78 (12) ◽  
pp. 1531-1544 ◽  
Author(s):  
Eric Nicolini ◽  
Daniel Barthélémy ◽  
Patrick Heuret
Keyword(s):  
Quercus Petraea ◽  
Growth Unit ◽  
Growth Morphology ◽  
Basal Diameter ◽  
Canopy Density ◽  
Sessile Oak ◽  
The North ◽  
Oak Trees ◽  
Branching Patterns ◽  
Number Of Branches

The growth and branching patterns of the main axis of 6-year-old sessile oak, growing in a natural regeneration in the north of France, were analysed each year retrospectively according to three increasing canopy density conditions: large gap, small gap, and dense canopy. Increasing gap size is associated with an increase in the total height, basal diameter, branching probability, and global polycyclism rate of the trees. At the growth unit or annual shoot level, from dense canopy to large gaps these botanical entities also show an increase in their total length, number of nodes, polycyclism, and branching rate as well as mean number of branches and mean internode length. A discussion of our results revealed some endogenous features of growth and branching patterns in young sessile oak trees. It is also shown that increasing canopy density generally tends to reduce the expression of the endogenous architectural sequence of differentiation of young sessile oak trees. Young trees growing below dense canopy thus seem to be "delayed" in their sequence of differentiation and appear to be in a "waiting" status, whereas young trees growing in large gaps exhibit an architecture very similar to trees growing in nurseries under nonlimiting growth conditions.Key words: architecture, Quercus petraea, growth, morphology, canopy density.

scholarly journals Drought or Severe Drought? Hemiparasitic Yellow Mistletoe (Loranthus europaeus) Amplifies Drought Stress in Sessile Oak Trees (Quercus petraea) by Altering Water Status and Physiological Responses

Water ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 2985
Author(s):  
Martin Kubov ◽  
Peter Fleischer ◽  
Jozef Rozkošný ◽  
Daniel Kurjak ◽  
Alena Konôpková ◽  
...  
Keyword(s):  
Water Status ◽  
Leaf Size ◽  
Quercus Petraea ◽  
Severe Drought ◽  
Sessile Oak ◽  
Leaf Transpiration ◽  
Oak Trees ◽  
Psii Photochemistry ◽  
Use Efficiency ◽  
Stem Increment

European oak species have long been considered relatively resistant to different disturbances, including drought. However, several recent studies have reported their decline initiated by complex changes. Therefore, we compared mature sessile oak trees (Quercus petraea (Matt.), Liebl.) infested versus non-infested by hemiparasitic yellow mistletoe (Loranthus europaeus Jacq.) during the relatively dry vegetation season of 2019. We used broad arrays of ecophysiological (maximal assimilation rate Asat, chlorophyll a fluorescence, stomatal conductance gS, leaf morphological traits, mineral nutrition), growth (tree diameter, height, stem increment), and water status indicators (leaf water potential Ψ, leaf transpiration T, water-use efficiency WUE) to identify processes underlying vast oak decline. The presence of mistletoe significantly reduced the Ψ by 1 MPa, and the WUE by 14%. The T and gS of infested oaks were lower by 34% and 38%, respectively, compared to the non-infested oaks, whereas the Asat dropped to 55%. Less pronounced but significant changes were also observed at the level of photosystem II (PSII) photochemistry. Moreover, we identified the differences in C content, which probably reduced stem increment and leaf size of the infested trees. Generally, we can conclude that mistletoe could be a serious threat that jeopardizes the water status and growth of oak stands.

scholarly journals Studies of Cryphonectria parasitica (MURR.) BARR subpopulations on Quercus petraea in Ukraine

2011 ◽  
pp. 70-75
Author(s):  
László Radócz ◽  
Gábor Tarcali ◽  
László Irinyi ◽  
Gábor Görcsös
Keyword(s):  
Fungal Pathogens ◽  
Castanea Sativa ◽  
Cryphonectria Parasitica ◽  
Quercus Petraea ◽  
Carpathian Basin ◽  
Chestnut Blight ◽  
Oak Trees ◽  
Compatibility Group ◽  
Laboratory Examinations ◽  
Blight Disease

Chryphonectria parasitica (Murr.) Barr, the casual agent of chestnut blight disease, which is one of the most important fungal pathogens of chestnut (Castanea sativa). The disease seriously affected the chestnut in Northern-America and in Europe as well. It is important to mention that the pathogen does not only infect the chestnut but oak species (Quercus spp.) also. In the Carpathian-Basin, the chestnut is endemic in the Mecsek mountains, in Zala, in Somogy counties but it also can be found in the Danube-Bend. In the Carpathian-Basin (outside Hungary) the chestnut is found in Slovakia, Ukraine, Romania. In our study bark samples infected by Cryphonectria parasitica were collected from Bobovyshche, Serednje and Rostovjatica (Ukraine). The rate of infected chestnut tree were higher than 90% around Bobovyshche and beside chestnut, the symptoms were detected on oak trees as well. We collected bark samples from chestnut and oak as well and then we isolated the pathogen Cryphonectria parasitica in the lab of University of Debrecen. Symptomatological observations, laboratory examinations on fungus morphology, as well as comparisons of ITS sequency homology were made and approved that the causal agent of new disease was Cryphonectria parasitica. Our results proved that the Cryphonectria. parasitica infects oak trees beside chestnut in the Carpathian-Basin. Further studies are needed to determine the VCG (Vegatative Compatibility Group) group of the Cryphonectria parasitica found on oak trees. 

scholarly journals Contribution to the Knowledge of Incidence, Development and Galls of the Bisexual Generation of Biorhiza pallida (Hymenoptera: Cynipidae)

2019 ◽  
Vol 67 (3) ◽  
pp. 771-785
Author(s):  
Jaroslav Urban
Keyword(s):  
Woody Plants ◽  
Research Study ◽  
Winter Season ◽  
Quercus Petraea ◽  
Gall Wasp ◽  
Epicormic Shoots ◽  
Growing Period ◽  
Oak Trees ◽  
Mean Diameter ◽  
Average Size

The research study deals with the occurrence, cecidogenesis and development of the bisexual generation of Biorhiza pallida in the Brno region. Galls were found most frequently on Quercus petraea and on Q. robur. At the end of the winter season, females deposited 2–290 (on average 83.6) eggs, mainly into the above average sized buds on last‑year’s shoots. Larvae came to age in May in the 3rd instar, in the extremely warm and dry growing period of 2015 already in the 2nd instar. Adult individuals were leaving galls from the end of May to the end of July. Females were 3–4.5 – times superior to males in numbers. Females, males and individuals of both sexes emerged from 64.3%, 21.4% and 14.3% of galls, respectively. Galls were created from the beginning of April. In the second half of April (or at the beginning of May) they were 3–35 (on average 15.2) mm high and 3–45 (on average 20.2) mm wide. The percentage of buds infestation, average number of deposited eggs and average size of galls were increasing with the increasing mean diameter of shoots. Parasitoids (incl. parasitoid inquilines) killed 30–100 (on average 65) percent of gall wasp population. We found as many as 40% and 10% of galls with the developing Curculio villosus (Curculionidae) and Synergus spp. (Cynipidae), respectively. In the spring of 2016, nearly the whole gall wasp population in Brno‑Komín was killed by late frosts. The pest infests mid‑aged woody plants, sporadically also young growths and epicormic shoots of old oak trees.

scholarly journals Biomass functions applicable to oak trees grown in Central-European forestry

2008 ◽  
Vol 54 (No. 3) ◽  
pp. 109-120 ◽  
Author(s):  
E. Cienciala ◽  
J. Apltauer ◽  
Z. Exnerová ◽  
F. Tatarinov
Keyword(s):  
Aboveground Biomass ◽  
Strong Predictor ◽  
Tree Height ◽  
Stem Bark ◽  
Quercus Petraea ◽  
Tree Age ◽  
Central European ◽  
Crown Length ◽  
Oak Trees ◽  
Biomass Functions

This study describes the parameterization of biomass functions applicable to oak (<I>Quercus robur, Quercus petraea</I>) trees grown in the conditions of Central-European forestry. It is based on destructive measurements of 51 grown trees sampled from 6 sites in different regions of the Czech Republic important for oak forest management. The samples covered trees of breast height diameter (<I>D</I>) ranging from 6 to 59 cm, tree height (<I>H</I>) from 6 to 32 m and age between 12 and 152 years. The parameterization was performed for total aboveground biomass and its individual components. The two basic levels of biomass functions utilized <I>D</I> either as a single independent variable or in combination with <I>H</I>. The functions of the third level represented the best function for each biomass component with the optimal combination of available independent variables, which included <I>D, H</I>, crown length (<I>CL</I>), crown width (<I>CW</I>), crown ratio (<I>CR = CL/H</I>), tree age and site altitude. <I>D</I> was found to be a particularly strong predictor for total tree aboveground biomass. <I>H</I> was found to always improve the fit, particularly for the individual components of aboveground biomass. The contribution of <I>CW</I> was minor, but significant for all biomass components, whereas <I>CL</I> and <I>CR</I> were found useful for the components of stem and living branches, respectively. Finally, the remaining variables tree age and altitude were each justified only for one component function, namely living branch biomass and stem bark, respectively. The study also compares the fitted functions with other available references applicable to oak trees.

The mycobiota in nonmycorrhizal roots of healthy and declining oaks

2004 ◽  
Vol 82 (10) ◽  
pp. 1446-1458 ◽  
Author(s):  
Erhard Halmschlager ◽  
Tadeusz Kowalski
Keyword(s):  
Fungal Community ◽  
Quercus Petraea ◽  
Species Assemblage ◽  
Cylindrocarpon Destructans ◽  
Oak Trees ◽  
Colonization Frequency ◽  
Root Fungi ◽  
Eastern Austria ◽  
Fungal Association ◽  
Isolated Species

A detailed survey of the mycobiota in roots of declining and healthy-looking oak trees was conducted at two sites in eastern Austria that clearly differed in humus and soil type and pH. Overall colonization of living and dead oak roots was 97.7% and 98.5%, respectively. Colonization frequency of the cortex was nearly twice that of the central cylinder in living roots. The species assemblage comprised 126 fungal taxa. Species composition varied greatly between sites and less between living and dead roots from the same site. Fungal association on living roots at Nieder weiden was dominated by Cadophora fastigiata Lagerb. & Melin, which occurred in 50% of roots, and Cylindrocarpon destructans (Zinssm.) Scholten. Together with Cryptosporiopsis melanogena Kowalski & Halmschlager and Basidio mycete R157, these two species were also the major components in dead roots. At Patzmannsdorf, the fungal community in living roots was dominated by Cystodendron sp. 1, Cadophora-like R018, and Cryptosporiopsis radicicola Kowalski & Bartnik, whereas in dead roots Xylaria hypoxylon (L. ex Hooker) Grev. was the dominant species. No substantial differences were found between the root mycobiota in healthy and declining trees. Apart from Armillaria ostoyae (Romagnesi Herink and Cylindrocarpon destructans, the majority of isolated species were considered endophytes or saprophytes that are most likely not involved in the dieback of oak roots.Key words: root fungi, Quercus robur, Quercus petraea, endophytes, fungal community, oak decline.

Sap-flow velocities and distribution of wet-wood in trunks of healthy and unhealthy Quercus robur, Quercus petraea and Quercus cerris oak trees in Hungary

Chemosphere ◽  
1998 ◽  
Vol 36 (4-5) ◽  
pp. 931-936 ◽  
Author(s):  
A. Fenyvesi ◽  
Cs. Béres ◽  
A. Raschi ◽  
R. Tognietti ◽  
H.-W. Ridder ◽  
...  
Keyword(s):  
Sap Flow ◽  
Quercus Robur ◽  
Quercus Petraea ◽  
Oak Trees ◽  
Quercus Cerris ◽  
Flow Velocities

Combined effect of thermosonication and high hydrostatic pressure on bioactive compounds, microbial load, and enzyme activities of blueberry juice

2021 ◽  
pp. 108201322110043
Author(s):  
Tianshun Chen ◽  
Bin Li ◽  
Chi Shu ◽  
Jinlong Tian ◽  
Ye Zhang ◽  
...  
Keyword(s):  
Phenolic Compounds ◽  
Hydrostatic Pressure ◽  
Enzyme Activities ◽  
High Hydrostatic Pressure ◽  
Radical Scavenging Activity ◽  
Radical Scavenging ◽  
Combined Effect ◽  
Soluble Solids ◽  
Microbial Load ◽  
Blueberry Juice

The current study is aimed to evaluate the combined effect of thermosonication (TS) and high hydrostatic pressure (HHP) on enzyme activities (polyphenolase and peroxidase), microbial load and phenolic compounds (phenols, flavonoids, and anthocyanins) of blueberry juice. Blueberry juice has been treated with TS (40 kHz and 240 W) at different temperatures (25 °C and 45 °C) for 15 mins with subsequent different HHP (200, 400 and 600 MPa) for 5 mins at room temperature. The results revealed that a combined use of HHP of 400 MPa and 600 MPa with TS at 45 °C not only reduced microorganisms below 1 logCFU/mL, but also significantly inactivated enzymes. The treatments also increased the phenolic compounds, peroxyl radical scavenging capacity (PSC), and DPPH free radical scavenging activity to a higher level without causing any changes in soluble solids and pH. Therefore, the combination of HHP and TS can be used as a novel alternative nonthermal technology to improve the nutritional qualities of blueberry juice, which produces a desirable, healthy juice for consumers.

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