scholarly journals Differentiation and structural decline in the leaves and bark of birch (Betula pendula) under low ozone concentrations

Trees ◽  
1993 ◽  
Vol 7 (2) ◽  
Author(s):  
MadeleineS. G�nthardt-Goerg ◽  
Rainer Matyssek ◽  
Christoph Scheidegger ◽  
Theodor Keller
Trees ◽  
1991 ◽  
Vol 5 (1) ◽  
Author(s):  
Rainer Matyssek ◽  
MadeleineS. G�nthardt-Goerg ◽  
Theodor Keller ◽  
Christoph Scheidegger

Beskydy ◽  
2012 ◽  
Vol 5 (1) ◽  
pp. 37-42
Author(s):  
Emilie Bednářová

Effects of above-limit ground-level ozone concentrations on the health condition of the silver birch (Betula pendula Roth) assimilation apparatus was monitored using the method of study of changes in epicuticular waxes. These waxes are present on the surface of leaves and protect the plant (and, especially, its assimilation apparatus) against negative environmental effects. Studies were performed in a tree stand of the 2nd age category in altitudes ranging from 600 to 1,050 m in the Ore Mountains (Krušné hory in Czech). It was found out that, as compared with a control stand, the thickness of the wax epicuticular layer decreased with the increasing altitude while concentrations of the ground-level ozone increased. A visible damage of the assimilation apparatus was observed in localities with the highest concentrations of ground-level ozone. Here, not only an overall decrease in the amount of epicuticular waxes was observed but also a degradation of their structure. A statistical analysis of results proved that the loss of epicuticular waxes was significantly dependent on above-limit concentrations of ground-level ozone.


Trees ◽  
1992 ◽  
Vol 6 (2) ◽  
Author(s):  
Rainer Matyssek ◽  
MadeleineS. G�nthardt-Goerg ◽  
Matthias Saurer ◽  
Theodor Keller

TAPPI Journal ◽  
2015 ◽  
Vol 14 (4) ◽  
pp. 237-244 ◽  
Author(s):  
JONI LEHTO ◽  
RAIMO ALÉN

Untreated and hot water-treated birch (Betula pendula) sawdust were cooked by the oxygen-alkali method under the same cooking conditions (temperature = 170°C, liquor-to-wood ratio = 5 L/kg, and 19% sodium hydroxide charge on the ovendry sawdust). The pretreatment of feedstock clearly facilitated delignification. After a cooking time of 90 min, the kappa numbers were 47.6 for the untreated birch and 10.3 for the hot water-treated birch. Additionally, the amounts of hydroxy acids in black liquors based on the pretreated sawdust were higher (19.5-22.5g/L) than those in the untreated sawdust black liquors (14.8-15.5 g/L). In contrast, in the former case, the amounts of acetic acid were lower in the pretreated sawdust (13.3-14.8 g/L vs. 16.9-19.1 g/L) because the partial hydrolysis of the acetyl groups in xylan already took place during the hot water extraction of feedstock. The sulfur-free fractions in the pretreatment hydrolysates (mainly carbohydrates and acetic acid) and in black liquors (mainly lignin and aliphatic carboxylic acids) were considered as attractive novel byproducts of chemical pulping.


2019 ◽  
Vol 24 (2) ◽  
pp. 66-74
Author(s):  
Kristina Krupey ◽  
◽  
Katerina Obruch ◽  
A. Mihailichenko ◽  
◽  
...  

Author(s):  
Р. Х. Гиниятуллин ◽  
Алексей Юрьевич Кулагин

Представлены материалы по оценке относительного жизненного состояния и аккумуляции металлов различными надземными органами березы повислой (Betula pendula Roth.) в условиях технического загрязнения Стерлитамакского промышленного центра (СПЦ). Показано, что насаждения березы в СПЦ способны депонировать техногенные металлы в этих условиях.


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