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991.
Rasoul Yousefpour Jette Bredahl Jacobsen Bo Jellesmark Thorsen Henrik Meilby Marc Hanewinkel Karoline Oehler 《Annals of Forest Science》2012,69(1):1-15
• Context
This review paper provides an overview of approaches to which we may resort for handling the complex decision problems involving uncertainty and risk that climate change implies for forest managers. Modelling approaches that could support adaptive management strategies seem to be called for, not only as climate change denotes increased economic uncertainty but also because new and more reliable information becomes available as time passes and climate changes. 相似文献992.
Staffan Berg Janine Fischbach Franka Brüchert Mikael Poissonnet Stefania Pizzirani Anne Varet Udo H. Sauter 《European Journal of Forest Research》2012,131(1):81-94
The forest-based sector has been at the forefront in operationally implementing the sustainability concept, its associated
principles and indicators for sustainable forest management. Several methods have been developed to study environmental impacts
of forestry activities, but none of the existing tools address all the dimensions of sustainability along the whole forest
wood chain (FWC) in a balanced way. Consequently, the decision was made to develop a tool for sustainability impact assessment
(ToSIA), the modelling framework for sustainability impact assessment of FWCs. The objective of the EU Project Eforwood was
to develop ToSIA, a decision support tool. Within ToSIA, a FWC is modelled as a number of interconnected processes. For each
process, a range of economic, environmental and social indicators and their respective values are calculated, thus representing
the three pillars of sustainability. By this method, the multifunctionality of forests can be assessed and supply chains can
be compared with respect to sustainability. Sensitivity analysis and scenario techniques can be applied to learn about the
effect of expected changes to the structure of the chain, the material flows and the indicator values. In order to provide
the tool with information about forest and logging operations, data were collected at two fundamental levels: (1) a regional
level with case studies in Scandinavia, Iberia and Baden-Württemberg and (2) a European level with a case study that reflects
conditions in the 27 countries of the European Union. This paper describes and details the harvesting and logging processes
for the European countries. The results are displayed for each of the three regional case studies as well as aggregated to
five principal areas in Europe: Eastern, Northern, Western, Central and Southwest Europe. 相似文献
993.
Javier Madrigal Eva Marino Mercedes Guijarro Carmen Hernando Carmen Díez 《Annals of Forest Science》2012,69(3):387-397
• Introduction
The abandonment of rural areas has led to an increase of the fire-prone European gorse (Ulex europaeus L.) communities in some regions, where prescribed burning is a technique applied to control them. Understanding flammability changes after treatments is crucial for the sustainable use of fire. 相似文献994.
Mustapha Bakry Mohammed S. Lamhamedi Jean Caron Hank Margolis Abdenbi Zine El Abidine M’Hammed Bellaka Debra C. Stowe 《New Forests》2012,43(3):267-286
The morpho-physiological quality of seedlings is negatively affected by the wide scale use of forest soils as substrates in
developing countries. With the objective of finding long-term sustainable supply of growing media, compost was produced from
shredded branches of three fast growing species (Acacia cyanophylla (AA), Acacia cyclops (AS) and Eucalyptus gomphocephala (EG). The composting process covered three different periods over the course of a year. Pile temperatures were monitored daily
and the composts were routinely sampled and analyzed for 19 chemical variables. Although composting is feasible year-round
in arid climates, compost produced in the humid cool conditions of autumn, winter and early spring reaches the maturation
phase more quickly than compost produced under hot, dry summer conditions. It also requires less turning and water. The evolution
of the composting process and quality of the final product can be assessed using three chemical variables (C/N, pH, EC). Seed
germination rates in the three types of compost were similar to that in a peat:vermiculite substrate and vigorous high quality
seedlings were produced in the two acacia composts. However, compost-grown seedlings had significantly smaller shoots and
root systems than those produced in peat substrate. Principal components analyses showed that the quality of a compost-based
substrate is reproducible and that its final chemical composition can be predicted from its raw organic materials. The EG composts had higher pH than the acacia composts, whereas the AA and EG composts were higher in mineral salts than the AS. 相似文献
995.
Lifting for handling and flatbed truck transportation to the job site are important processes during manufacture of prefabri-cated wooden construction units like mini homes and building modules. Significant damage can occur to sections or components of units during these operations. Although damage usually will not impair its structural safety, it is costly to fix and causes the public to perceive prefabricated wooden buildings as low quality products. Field observations and preliminary numerical models for prefabri-cated units subject to lifting and transportation forces are summarized here. Once fully developed and verified, models will support the creation of damage mitigation strategies centered on structural details indicating how units are to be supported during lifting and transportation. 相似文献
996.
由EST获得全长cDNA对于结构基因组学和功能基因组学都是至关重要的,cDNA末端快速扩增技术RACE是该领域中的重要研究方法.利用BD SMART RACE技术扩增编码分泌天冬氨酸蛋白酶SA76基因的3'末端,将其与哈茨木霉cDNA文库中的SA76基因的EST序列进行序列拼接,获得2019bp的全长cDNA序列,其开放读码框长1593bp,5'非编码区266bp,3'非编码区201bp,编码530个氨基酸,有信号肽.哈茨木霉天冬氨酸蛋白酶基因与玉蜀黍赤霉、粗糙脉孢菌、球毛壳菌天冬氨酸蛋白酶基因的同源性分别为53%, 37%, 36%.利用BD SMART RACE技术首次从哈茨木霉中克隆天冬氨酸蛋白酶基因,为验证SA76基因的功能奠定基础,为进一步研究蛋白酶的作用机制及生物防治功能提供依据. 相似文献
997.
林业生态工程效益补偿问题研究初探 总被引:1,自引:0,他引:1
生态效益补偿对于促进林业生态工程建设、保护森林生产者和经营者的切身利益具有重要的作用.本文在分析国内外生态效益补偿现状的基础上,通过对建立森林生态效益补偿机制的必要性、原则、途径以及补偿标准等问题进行深入探讨,为进一步完善我国森林生态效益补偿机制提供科学依据.森林生态效益补偿资金的建立,不仅为森林资源管护提供稳定的资金来源,更是对森林生态效益价值的认可,从根本上解决了林业生态工程建设的动力和机制问题,将对中国林业和生态建设产生广泛而深远的影响. 相似文献
998.
MA-SEBS as compatibilizer and impact modifier was incorporated into Polypropylene/Wood Fiber (PP/WF) to enhance interface adhesion and impact strength of the composite. The effect of MA-SEBS content on the impact fracture behavior of PP/WF composites was studied. The impact properties of composites with 8% MA-SEBS reached the maximum value. And further increasing of MA-SEBS content to 10% did not improve the fracture toughness, but improved the stiffness of composites by DMA analysis. This was attributed to the improved PP/WF adhesion. As the MA-SEBS content is more than 8%, the molecule interaction of PP and WF was expected to much stronger than lower MA-SEBS. Scanning electron microscopy (SEM) was performed to analyze the impact fracture surface and showed a stronger affinity for the wood surfaces. 相似文献
999.
Influence of Ammoniacal Copper Quaternary treatments on mechanical properties of blue-stained Lodgepole Pine wood 总被引:1,自引:0,他引:1
Three concentrations (2.8%, 2.0%, 1.2%) of Ammoniacal Copper Quaternary (ACQ) was selected to treat Lodgepole pine wood for evaluating ACQ treatment on mechanical properties of blue-stained wood. The bending modules of elasticity (MOE), modules of rupture (MOR), toughness and shearing strength parallel to grain on tangential surface, are tested according to the criteria GB1927-1943-91. Non-treated sample were also tested according to the same procedure. The results showed that the three groups specimen impregnated by different concentrations of ACQ solution met the AWPA standard 2003 of America (UC4A 6.4g/cm^3). There were significant difference of toughness between treated wood and non-treated wood (p=0.01), but there were no statistically significant differences among three concentrations in terms of toughness, and toughness of treated wood was approximately 20% lower than non-treated. MOR, MOE as well as sheafing strength parallel to grain were found to be not significantly different between treated wood and non-treated one, and there were no statistically significant difference among three concentrations of ACQ too. Toughness, MOR, MOE and sheafing strength parallel to grain increased with decrease of concentration of ACQ, but they were hardly affected by ACQ preservatives. 相似文献
1000.
The germination of common alder (Alnus glutinosa (L.) Gaertn.) and downey birch (Betula pubescens Ehrh.) seeds is often poor in bare-root nurseries. The effect of a variety of seed coverings and a few seed pretreatments
on seedling emergence was examined in this study in an attempt to address this problem. Seeds of each species were sown in
trays containing nursery soil, covered with grit, gravel, sand, combinations of these coverings, a hydromulch or a sealed
plastic cloche and then incubated for 6 weeks at 17–20°C. The grit combined with sand or gravel, the hydromulch and the cloche
increased seedling emergence when compared with the standard grit. In another experiment, seeds of each species were fully
imbibed (FI) (>50% moisture content, MC), as per standard practice, or adjusted to target MC (TMC) (30–35% MC) levels, and
then chilled to release dormancy. Some seeds of each MC treatment were primed at 20°C for 2 days following chilling, after
which all seeds were evaluated in laboratory tests and a nursery trial. Germination potential of the FI seeds declined in
the lab tests by the second test date, which was reflected in low seedling emergence in the nursery in birch. The primed FI
seeds of alder germinated most rapidly in the nursery, but other effects were not significant. Seedling emergence was better
in the nursery in response to the TMC than the FI pretreatment in birch.
相似文献
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