Optimization of sucrose and inorganic nitrogen concentrations for somatic embryogenesis of birch (Betula pendula Roth.) callus cultures: A statistical approach

1991 ◽  
Vol 24 (2) ◽  
pp. 73-77 ◽  
Author(s):  
Anna Maria Nuutila ◽  
Ulrika Kurt�n ◽  
Veli Kauppinen
1990 ◽  
Vol 23 (2) ◽  
pp. 101-105 ◽  
Author(s):  
Ulrika Kurt�n ◽  
Anna Maria Nuutila ◽  
Veli Kauppinen ◽  
Matti Rousi

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.


Forests ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 599
Author(s):  
Héloïse Dubois ◽  
Hugues Claessens ◽  
Gauthier Ligot

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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