نتایج جستجو برای: picea abies

تعداد نتایج: 6016  

2005
Daowei Zhang David N. Wear

This study addresses an important dimension concerning the softwood lumber trade dispute between United States and Canada-substitutability among imported and domestically produced species. We employ the restricted translog subcost function approach to study this issue based on the monthly data of US softwood products consumption and prices between Jan. 1989 and July 2001. The results show that ...

2011
Kadri Koorem Jodi N. Price Mari Moora

The effect of litter on seedling establishment can influence species richness in plant communities. The effect of litter depends on amount, and also on litter type, but relatively little is known about the species-specific effects of litter. We conducted a factorial greenhouse experiment to examine the effect of litter type, using two woody species that commonly co-occur in boreonemoral forest-...

2008
Asghar Tarmian Mohammad Azadfallah

A number of important anatomical features and chemical composition in opposite, normal, and compression wood of Norway spruce (Picea abies) were evaluated to optimally utilize spruce logs containing compression wood. A comparison of axial tracheid and ray cell features in the opposite, normal, and compression wood was provided. Lignin, cellulose, acetone-soluble, and water-soluble extractive co...

Journal: :Bulletin of mathematical biology 2008
Naveen K Vaidya Jianhong Wu

Understanding the dynamics of spruce budworm population is very important for the protection of spruce and balsam fir trees of North American forests, and a full understanding of the dynamics requires careful consideration of the individual physiological structures that is essential for outbreak control. A model as a delay differential equation is derived from structured population system, and ...

2014
Lara Valentín Tiina Rajala Mikko Peltoniemi Jussi Heinonsalo Taina Pennanen Raisa Mäkipää

Hundreds of wood-inhabiting fungal species are now threatened, principally due to a lack of dead wood in intensively managed forests, but the consequences of reduced fungal diversity on ecosystem functioning are not known. Several experiments have shown that primary productivity is negatively affected by a loss of species, but the effects of microbial diversity on decomposition are less studied...

Journal: :Environmental microbiology 2016
Lucia Žifčáková Tomáš Větrovský Adina Howe Petr Baldrian

Understanding the ecology of coniferous forests is very important because these environments represent globally largest carbon sinks. Metatranscriptomics, microbial community and enzyme analyses were combined to describe the detailed role of microbial taxa in the functioning of the Picea abies-dominated coniferous forest soil in two contrasting seasons. These seasons were the summer, representi...

Journal: :Tree physiology 1995
U Niinemets O Kull

Needle dimensions, needle surface area, needle dry weight per area (LWA) and needle density (ND, needle weight per volume) were measured in terminal current-year shoots in a natural canopy of variably sized Picea abies (L.) Karst. trees growing along a light gradient. Needle shape was described as a rhomboid. Needle width (D(2)) increased with increasing diffuse site factor, a(d) (relative amou...

2013
Martin Gspaltl William Bauerle Dan Binkley Hubert Sterba

Silviculture focuses on establishing forest stand conditions that improve the stand increment. Knowledge about the efficiency of an individual tree is essential to be able to establish stand structures that increase tree resource use efficiency and stand level production. Efficiency is often expressed as stem growth per unit leaf area (leaf area efficiency), or per unit of light absorbed (light...

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