搜索结果: 1-15 共查到“birch”相关记录42条 . 查询时间(0.137 秒)
Below-canopy and topsoil temperatures in young Norway spruce and Carpathian birch stands compared to gaps in the mountains
air soil below-canopy climate microclimate stand environment
2016/11/11
Reduced air pollution load has allowed to use commercially oriented forestry in the Central European mountains since the 1990s. The goal is, however, to restore species- and age-diversified stable sta...
Birch (Betula papyrifera) × white spruce (Picea glauca) interactions in mixedwood stands: implications for managementv
boreal forest competition mean annual DBH growth productivity relative density index (RDI) vegetation management
2015/4/24
Current British Columbia forest regulations drive the regeneration management towards pure conifer stands rather than remaining in a mixed-species condition. This approach may result in unnecessary ve...
Snow damage to birch stands in Northern Moravia
birch fertile sites growth natural regeneration snow damage slenderness ratio root system
2015/4/14
The condition and snow damage to stands dominated by birch were studied in the area of interest in Northern Moravia. Based on basal area, the share of birch ranged from 68 to 88%. The stands came to e...
How much birch (Betula papyrifera) is too much for maximizing spruce (Picea glauca) growth: a case study in boreal spruce plantation forests
competition future value growth and yield model forest management productivity
2015/4/14
Interest in conifer-broadleaf mixedwood forests has greatly increased due to continuous demand for hardwood products and a shift towards more biological or ecosystem-based management. In British Colum...
Effects of nitrogen on growth properties and phenology of silver birch (Betula pendula Roth)
nitrogen silver birch stress phenology of budbreak leaf-fall frost heaving
2015/4/14
Effects of stress caused by differentiated inputs of nitrogen after the application of ammonium nitrate (NH4NO3) on silver birch (Betula pendula Roth) were monitored in a greenhouse. The applied ammon...
Response of birch (Betula pendula Roth) phytophages to liming
birch Betula pendula Roth liming dolomitic limestone phytophages Eriophyes leionotus
2015/3/12
In the course of 2004–2007, the effects of compensation liming at the application dose of 1.5–3–6 t/ha dolomitic limestone on the elimination or activation of phytophages or other types of damage resu...
BiRch：一种处理k步可达性查询的双向搜索算法
k步可达性查询 双向搜索 广度层数 拓扑层数
2015/12/22
针对现有方法低效或索引规模庞大的问题,提出一种双向搜索算法Bi Rch。当判断顶点u是否满足k步可达顶点v时,首先比较u的出度和v的入度,优先处理度小的顶点。其优点体现在使用较小的索引,同时避免由于u的出度过大所带来的效率下降问题;提出基于双向广度层数和双向拓扑层数的剪枝策略来辅助过滤,减少需要访问的顶点数量。基于19个真实数据集进行测试,实验结果从索引构建时间、索引大小、查询响应时间、处理顶点数...
Influence of a planting hole application of dolomitic limestone powder and basalt grit on the growth of Carpathian birch (Betula carpatica W. et K.) and soil chemistry in the air-polluted Jizerské hory Mts.
acidic deposition forest ecosystems
2015/3/5
The objective of the study was to evaluate the growth potential of Carpathian birch (Betula carpatica W. et K.) at an environmentally harsh mountain site and a response of this species to altered soil...
Geometridae (Insecta: Lepidoptera) in stands of substitute species with the dominant position of birch
larvae Betula pendula Kruš né hory Mts.
2015/3/3
The species spectrum of Geometridae, their seasonal and population dynamics and importance for the
stability of birch stands in the air-polluted area of the Krušné hory Mts. was derived from a ...
Frost cracks and their effect on the stability of birch stands in the Krušné hory Mts.
Betula pendula Roth frost cracks icing
2015/3/3
Frost cracks which originated in birch due to bending during long-term icing in winter 1995/1996 became
the place of entrance for the attack of birch stems by Piptoporus betulinus (Bull. ex Fr.) Kar...
Feeding of the willow leaf beetle Lochmaea capreae L. (Coleoptera, Chrysomelidae) on leaves of birch (Betula pendula Roth) contaminated by heavy metals
Lochmaea capreae cadmium manganese lead zinc feed preference laboratory conditions
2015/2/2
The effect of contamination of birch (Betula pendula Roth) leaves with heavy metals on the feeding of imagoes of the willow leaf beetle (Lochmaea capreae L.) was studied under laboratory conditions. T...
The effect of stress factors on birch Betula pendula Roth
Betula pendula stress acid rain sulphur nitrogen drought grow phenology
2015/2/2
In a controlled pot trial, plants of birch (Betula pendula Roth) were treated in six variants: acid watering (pH 3), acid watering with spraying, drought, ammonium sulphate fertilisation, ammonium sul...
Ecological aspects of dispersion of gall mites in the vertical profile of the birch crown
Acalitus rudis Phyllocoptes lionotus tree crown dispersion ecology
2015/2/2
In stands of birch Betula pendula Roth in the eastern Krušné hory Mts. the occurrence of the gall mites Acalitus rudis Canestrini and Phyllocoptes lionotus Nalepa was studied in terms of their di...
Hymenoptera (Aculeata) in birch stands of the air-polluted area of Northern Bohemia
Hymenoptera Aculeata Betula pendula
2015/1/29
The Hymenoptera (Aculeata) fauna was studied in birch stands (Betula pendula Roth) of colder areas of Northern Bohemia using the method of Moericke’s yellow traps. Altogether 159 species were trapped;...
The role of root system in silver birch (Betula pendula Roth) dieback in the air-polluted area of Krušné hory Mts
Betula pendula Roth root system air pollution
2015/1/29
120 root systems and trunks of 20 years old birch trees and 60 root systems and trunks of 15 years old birch trees affected by defoliation and with no visual symptoms of damage were analyzed in the ai...