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881.
Frauke Kleemann Maximilian von Fragstein Barbara Vornam Annika Müller Christoph Leuschner Andrea Holzschuh Teja Tscharntke Reiner Finkeldey Andrea Polle 《European Journal of Forest Research》2011,130(5):707-716
Knowledge on phenological, morphometric, and phytochemical variation of local progenies of European aspen (Populus tremula, L.) is limited. The goal of this study was to characterize variation in growth and ecologically important leaf properties
in aspen full-sib families in relation to interacting organisms (mycorrhiza, endophytes, and insects) and to determine whether
these interactions were affected by soil application of a systemic fungicide. In local progenies, within-family variation
of neutral molecular genetic markers (nuclear microsatellites) was higher than between families. Significant variation in
growth, production of phenolic defensive compounds and other phytochemical leaf traits was found between families. Phenolic
compounds showed clear negative correlation with generalist herbivores, but did not result in negative trade-off with biomass
production. Differences in mycorrhizal colonization were not found among full-sib families and application of a systemic fungicide
suppressed neither mycorrhizal colonization nor infestation with insects. However, a strong suppression of endophytes occurred,
whose long-term consequences may require attention when fungicides are used in agroforestry plantations. 相似文献
882.
François Pimont Jean-Luc Dupuy Rodman R. Linn Sylvain Dupont 《Annals of Forest Science》2011,68(3):523-530
Introduction
Forest fuel management in the context of fire prevention generally induces heterogeneous spatial patterns of vegetation. However, the impact of the canopy structure on both wind flows and fire behavior is not well understood. 相似文献883.
Celia Herrero de Aza María Belén Turrión Valentín Pando Felipe Bravo 《Annals of Forest Science》2011,68(6):1067-1076
• Context
Understanding biological processes in forests is necessary to orientate ecosystem management towards potential C sequestration. To achieve this, information is required about changes in forest biomass C pools, including the stem components (bark, sapwood and heartwood). 相似文献884.
• Background
In the development of pure beech and pure spruce pristine forests, we assume there should be a continuous transition from full stocking to successive disintegration and, finally, total replacement of the first generational wave at the end of its lifetime, dependent on mortality due to overcrowding as well as ageing, leading newly recruited cohorts to grow up from below. 相似文献885.
Yoshiharu Nishiyama 《Journal of Wood Science》2009,55(4):241-249
The current structural models of the cellulose microfibril as well as its mechanical and thermal properties are reviewed.
The cellulose microfibril can be considered as a single thin and long crystalline entity with highly anisotropic physical
properties. The contribution and limit of different methods employed such as electron microscopy, infrared spectroscopy, X-ray
scattering and diffraction, solid state nuclear magnetic resonance spectroscopy, and molecular modeling are also discussed. 相似文献
886.
Teodora B. Toshova Éva Csonka Mitko A. Subchev Miklós Tóth 《Journal of pest science》2009,82(3):295-303
Using allyl-isothiocyanate-baited traps, we recorded six species of flea beetles in cabbage and horseradish crops in the region
of Sofia, Bulgaria in 2006 and 2007. The most abundant species in the traps was Ph. cruciferae (92–96%) followed by Ph. vittula, Ph. undulata and Ph. nigripes. The overwintering adults of these species emerge before the beginning of April and are active to the end of May–beginning
of June. Catches of adults of the new generation occurred from the end of June–beginning of July to the second half of October–beginning
of November. In 2006, air temperature and humidity strongly influenced the catches of the flea beetles. Investigations of
the reproductive status of field collected females of Ph. cruciferae showed that this species develops one generation per year in the region. The results of this study can be used in integrated
pest management approach to flea beetles control. 相似文献
887.
Ingolf Profft Martina Mund Georg-Ernst Weber Eberhard Weller Ernst-Detlef Schulze 《European Journal of Forest Research》2009,128(4):399-413
Wood products are considered to contribute to the mitigation of carbon dioxide emissions. A critical gap in the life cycle
of wood products is to transfer the raw timber from the forest to the processing wood industry and, thus, the primary wood
products. Therefore, often rough estimates are used for this step to obtain total forestry carbon balances. The objectives
of this study were (1) to examine the fate of timber harvested in Thuringian state forests (central Germany), representing
a large, intensively managed forested region, and (2) to quantify carbon stocks and the lifetime of primary wood products
made from this timber. The analyses were based on the amount and assortments of actually sold timber, and production parameters
of the companies that bought and processed this timber. In addition, for coniferous stands of a selected Thuringian forest
district, we calculated potential effects of management, as expressed by different thinning regimes on wood products and their
lifetimes. Total annual timber sale of soft- and hardwoods from Thuringian state forests (195,000 ha) increased from about
136,893 t C (~0.7 t C ha−1 year−1) in 1996 to 280,194 t C (~1.4 t C ha−1 year−1) in 2005. About 47% of annual total timber harvest went into short-lived wood products with a mean residence time (MRT) < 25
years. Thirty-one per cent of the total harvest went into wood products with an MRT of 25–43 years, and only 22% was used
as construction wood and glued wood, products with the longest MRT (50 years). The average MRT of carbon in harvested wood
products was 20 years. Thinning from above throughout the rotation of spruce forests would lead to an average MRT in harvested
wood products of about 23 years, thinning from below of about 18 years. A comparison of our calculations with estimates that
resulted from the products module of the CO2FIX model (Nabuurs et al. 2001) demonstrates the influence of regional differences in forest management and wood processing industry on the lifetime of
harvested wood products. To our knowledge, the present study provides for the first time real carbon inputs of a defined forest
management unit to the wood product sector by linking data on raw timber production, timber sales and wood processing. With
this new approach and using this data, it should be possible to substantially improve the net-carbon balance of the entire
forestry sector. 相似文献
888.
A study was conducted to assess the role and effectiveness of community organisers in supporting the development of people’s
organisations in achieving community-based forest management objectives in Leyte Province Philippines. Community organisers
were found to be effective in forming people’s organisations (POs), motivating people to participate in voluntary activities
organised by POs and encouraging cohesiveness among PO members. Community organisers manage to raise the level of environmental
awareness and knowledge of members of people’s organisations, develop leadership interest and skills, create various livelihood
opportunities and provide direction and facilitate the establishment of large tree plantations. However, the short duration
of community organisers’ contracts (typically two years) is insufficient to establish mature and cohesive POs prepared to
assume management on their own, including the management of tree plantations. Further, lack of training and funding support,
low wages, delayed payment of salaries and limited time to work with people’s organisations, as well as the pressure to produce
tangible outputs such the establishment of large tree plantations, prevents them from placing greater emphasis on the development
and empowerment of the people. 相似文献
889.
890.