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1.
Two field trials were conducted to study the rate of release of nutrients and heavy metals from wood and peat ash fertilizers in forest soils. In the first experiment, ash particle residues were extracted from peat and mineral soils 3 and 5 years after spreading and analysed for changes in element concentrations. Dissolution of different ash fertilizer products was also estimated by measuring the changes over time in the recovery of added nutrients and heavy metals in the surface of two peat soils. The results showed that potassium (K), sodium (Na), boron and sulfur are easily released from wood ash, whereas heavy metals are highly insoluble in all types of ash fertilizer products. Granulated ash fertilizers were less soluble than powdered fertilizers and the products stabilized by self-hardening. Minor differences occurred in ash fertilizer dissolution between peat and mineral soils and soils of different fertility. The most significant difference between wood and peat ash concerning their dissolution was the low solubility of K and Na in peat ash. Given the very slow dissolution of ash fertilizers, long-term studies are needed to understand fully the effect of ash fertilization on nutrient and heavy metal cycling in forest ecosystems.  相似文献   

2.
Focus groups were carried out in Austria, Finland, France, Norway, and Sweden to understand building professional’s and laypeople’s perceptions of building materials and well-being in indoor environments. Focus groups asked participants to share their opinions and experiences related to seven main topics: choosing interior materials, naturalness, naturalness for building materials, well-being in the indoor environment, wood materials, cleanabililty, and ethics and environment. The main objective of the focus groups was to explore how the use of wood is perceived in the interior environment and suggest opportunities for use of wood in the built environment. Participants’ responses can be linked to the physical properties of wood: density/hardness, grain, thermal conductivity, moisture content, chemical composition, color, and natural origin. Based on the discussion, these physical properties can be related more closely to the perception of wood as a natural material with respect to intended use, such as visual and tactile products. Based on the findings, it is also possible to alter product properties to enhance users’ experience of wood in the interior built environment. The results also indicate that the relevance and trustworthiness of the current schemes for documenting sustainable forestry practices, is questionable.  相似文献   

3.
Wood ash use in forestry - a review of the environmental impacts   总被引:2,自引:0,他引:2  
Pitman  Rona M. 《Forestry》2006,79(5):563-588
The use of wood fuel for energy production in the UK is setto increase in the near future as part of a government commitmentto increase renewable sources to 10 per cent by 2010. The ashgenerated as a by-product of combustion, whether for heat orpower generation, has potential use as a fertilizer in forestsystems. This review assesses the available information on factorsaffecting the quality of the ash and environmental implicationsarising from its application. The key determinants of wood ashchemistry are the tree species combusted, the nature of theburn process and the conditions at the application site. Woodash from hardwood species produces higher levels of macronutrientsin their ash than conifers, and the silica content is frequentlylower. A furnace temperature between 500 and 900°C is criticalto the retention of nutrients, particularly potassium, and determinesthe concentrations of potentially toxic metals including aluminiumin the ash. Fly ash, the lightest component that accumulatesin the flue system, can contain high concentrations of cadmium,copper, chromium, lead and arsenic and this ash should not beused as fertilizer. The form of the ash at application is important,with loose ash releasing Ca, K and Na more rapidly than granulatedash. Heavy metal, radionuclide and dioxin contamination of woodash-based fertilizers is minimal and unlikely to affect ecosystemfunction. The effects of wood ash are primarily governed byapplication rate and soil type. The benefits are maximized atlow dose rates, with possible toxicity from applications inexcess of 10 t ha–1. For most forest sites, a single woodash application per rotation could replace all the nutrientslost after whole-tree harvesting (excepting N). Long-lastingpositive effects on tree growth have been observed on shallowpeats, in which the humus is slowly mineralized in responseto elevated pH and increased nutrient availability. In contrast,wood ash application to podzols is only effective in enhancingtree growth when nitrogen availability is non-limiting. To date,published research of wood ash effects on trees growing in claysand loams is minimal. A lag time for positive tree responsesto wood ash application is often observed, and may be the resultof phosphorous limitation at higher soil pH. The greatest reportedadverse ecological effects are to acidophilic ecosystems, particularlythe constituent bryophyte, soil bacteria and ectomycorrhizalcommunities.  相似文献   

4.
By considering trade-offs and complementarity between carbon removal from the atmosphere by forests and emission reduction by wood use, we developed a forest-sector carbon integrated model for Japan. We discuss mitigation measures for Japan based on model projections. The integrated model included the forest model and the wood use model. Based on three scenarios (baseline, moderate increase, and rapid increase) of harvesting and wood use, the integrated model projected mitigation effects including carbon removal by forests and emission reduction through the wider use of wood, until 2050. Results indicate that forests will not become a source of net carbon emissions under the three scenarios considered. The baseline scenario is most effective for mitigating climate change, for most periods. However, the sum total of carbon removal in forests and carbon emission reductions by wood use under the rapid increase scenario exceeded the one of the moderate increase scenario after 2043. This was because of strong mitigation activities: promoting replanting, using new high-yield varieties, and wood use. The results also indicated that increases in emission reduction due to greater wood use compensated for 67.9 % of the decrease of carbon removal in 2050, for the rapid increase scenario. The results show that carbon removal in forests is most important in the short term because of the relative youth of the planted forests in Japan, and that mitigation effects by material and energy substitution may become greater over the longer term.  相似文献   

5.
It is generally believed that forests are perceived differently according to the cultural background of the visitor. Different cultural groups tend to have diverse perceptions of tree species, landscapes, or gardens. In this research project, we conducted interviews of German and Japanese groups (each group consisting of three or more people), to identify their perspectives in exploring the theme of “cut” and “dead” wood. For this purpose, we interviewed 20 groups from each cultural background (40 data sets in total). Each group was asked to categorize 36 pictures chosen from photographic contests. The results were examined with PCA and cluster analysis. The quantified results of the two national groups highlighted the dichotomy of the cut and dead wood relationship. The method and materials used gave robust results. Differences between the two groups were identified by their perceptions of cut and dead wood. The results are insightful from a methodological and political rationale. First, new insights were gained by adopting group-based interviews using pictures from photographic contests. Research about public perceptions in forest science is often dominated by a focus on verbal inquiry. This study explored similar questions, using visual materials. The interviews consisted of visual materials to overcome bias in languages or the question order. Second, the results indicated the influence of “close-to-nature forestry” policy on public perceptions. While German society has a wide practice of leaving dead wood in forests based on their close-to-nature forestry policy, there is no equivalent Japanese concept. Although Japan and Germany both face pressures for economic restructuring and public participation, the difference in public perception of forestry can lead to a difference in acceptance for the same policy. If such differences are to exist, we can observe that the legitimacy of forestry in the two countries is reconstructed in different ways.  相似文献   

6.
松材线虫对湖南林业和生态环境影响的风险性分析   总被引:12,自引:0,他引:12  
遵循国际植物保护公约(IPPC)制定的有害生物分析准则,结合森林植物检疫对象的特点,从地理和管理标准、传入、定殖、定殖后扩散的可能性、潜在的经济和环境重要性在对松材线虫传入湖南进行了风险分析。证明松材线虫完全符合检疫性有害生物地理和管理标准,随松类植物及产品的调运从国内外疫区传入的可能性极大,在湖南完全能够定殖,定殖后能迅速扩散并暴发成灾,不仅对全省林业生产影响极大,而且严重威胁世界自然遗产武陵源风景区的安全,提出了3种降低风险的管理措施。  相似文献   

7.
A pine forest in the south of Sweden was treated with lime and wood ash. In early June, 12 months after the ash treatment and 18 months after the lime treatment, one year old Pinus syhestris L. seedlings were planted. Four months later six différent ectomycorrhizal types had infected the seedlings in all the treatments. A mycorrhizal type designated “pink”; was more than twice as common in the lime treatments as in the control and ash treatments. Piloderma croceum Erikss. & Hjorts. was significantly more abundant in limed soil than in ash treated soil. The results were compared to those from a bioassy performed in the laboratory, where P. syhestris seedlings had been grown in soil from the same forest. Similar soil pH values in the two studies resulted in different relative infection rates of the mycorrhizal types found. One additional mycorrhizal type, designated “white”; was found in the field experiment. This suggests that mycelial connections to the mature host plants may significantly alter the ability of different fungi to colonize host plant roots in competition with each other compared to when the fungi infect from propagules in the soil.  相似文献   

8.
Granulated wood ash has been proposed as a slow release fertiliser suitable for forest soils. In this study ectomycorrhizal colonisation of roots and ash granules was studied in a 40-year-old spruce forest treated with 0, 3 or 6 t ha−1 granulated wood ash. We used PCR-RFLP methods for ITS-typing and identification of ectomycorrhizal fungi. In total 20 different ITS-types were recognised on roots in the organic soil horizon. Five of these were identified to species and two to genus. Six species, Tylospora fibrillosa Donk, Cortinarius sp. 3, Piloderma sp. 1, and three unidentified ITS-types (Ve-95-1, Tö-95-3 and Ve-95-9) each occurred on over 5% of the total root tips analysed. Together these comprised 55% of the ectomycorrhizal community on the screened roots.

Ash granules collected from the fertilised plots were normally colonised by fungal mycelia. PCR-RFLP analysis of these mycelia revealed the presence of four ITS-types. Three of these (Piloderma sp. 1, Ha-96-3 and Tor-97-1) were also present on the mycorrhizal roots. Piloderma sp. 1 was the most abundant species colonising roots. A possible role of ectomycorrhizal mycelia in the direct mobilisation of nutrients from ash granules is discussed.  相似文献   


9.
茶秆竹营林技术与竹鞭生长关系的研究   总被引:2,自引:0,他引:2  
欧建德 《江苏林业科技》2000,27(6):18-19,60
在田间试验的基础上,调查分析了不同营林技术对茶秆竹地下鞭生长,侧芽分化的影响。  相似文献   

10.
我国南方食用菌原料林培育研究进展   总被引:10,自引:2,他引:10       下载免费PDF全文
香菇等食用菌在我国具有近千年的栽培历史,是山区经济发展的重要产业,食用菌原料林的培育对于以阔叶权赤原食用菌产业持续发展意义重大。本文重点对食用菌原料林树种的优选、人促更新定向培育、主要原料林树种的丰产栽培以及其采种基地建设等进行述评。根据食用菌原料林培育研究现状和存在问题,提出进一步发展的技术对策和今后的研究重点,包括主要原料树树的种的良种选育和扩繁技术、育苗技术、松杉林冠下造林技术和多种食用菌原料林树种混植技术、二代食用菌原料林的萌芽更新技术等。  相似文献   

11.
《Southern Forests》2013,75(2):99-105
South Africa has made excellent progress in breeding plantation trees fulfilling the primary demands of improved volume growth, stem and branching characteristics, tolerance to pests and diseases, and general adaptability. This has had marked positive impacts on wood quality, as straight stems normally contain no or very little reaction wood, while problems associated with pith eccentricity and wandering pith are kept to a minimum. The breeding of trees with small, well-distributed branches, forming large angles with the vertical axis of the tree stem, reduced performance problems associated with knots and knot-associated features. However, tree breeding and intensive silviculture are causing the average corewood diameter to increase, creating a wood resource that is increasing in variability, especially when combined with earlier harvesting. Reducing the size and improving the properties of the corewood zone have therefore become of utmost importance to ensure that the South African pine timber resource continues to meet quality demands related to strength, stiffness and stability. Breeding programmes to date have created sound bases for further wood quality improvement of the various pine species, especially of the corewood zone. Opportunities for success are excellent as large variation in corewood properties still exists within the current breeding populations, combined with operationally important wood properties, such as wood density, microfibril angle, spiral grain and transitional age, all being under moderate to strong genetic control. Corewood properties seem to be inherited largely independently of tree and growth characteristics, making it possible to combine improvement in these characteristics with desirable wood properties. This paper discusses results from several young field trials, which have shown marked family, species and site differences in wood stiffness. This suggests that there is good opportunity to increase the dynamic modulus of elasticity of corewood by early selection and breeding, using highly reliable non-destructive acoustic technology. The results also proved that vegetative propagation through cuttings has no detrimental effect on corewood stiffness. The latter may even increase with increasing physiological age of the cutting.  相似文献   

12.
《Southern Forests》2013,75(4):169-183
An overview of southern African research that has investigated the impact of management practices that can potentially affect the long-term site productivity of plantations is presented, with an emphasis of these impacts on soil productivity and with the implications for multiple-rotation site productivity. Activities that are most likely to cause long-term changes in soil productivity are identified as those causing high site disturbance during the inter-rotation period, notably ground-based mechanised operations and harvest residue management (including complete biomass removal) and, under some conditions, fertilisation. The impacts of these practices on soil and stand productivity are discussed from a southern African perspective. Knowledge gaps are identified and it is suggested that the immediate research priority is to identify meaningful indicators that are sensitive to change and that can be linked to stand production. Other key research focus areas are proposed and the need for a permanent long-term monitoring network is highlighted.  相似文献   

13.
林权制度是林业发展的基础,林权改革是林业改革的核心。我国集体林权制度在不同时期的改革实践中不断发展,并取得了一定成果。但由于目前林权权属的不明确及不断地林权改革导致的不稳定性以及相应的融资及实施体系不完善等问题,使得林权改革仍需不断努力。从法律、政策和制度上明确产权,建立或调整相应的配套法律、政策措施,建立并完善多种形式并存的集体林经营体制,及相应的支持体制。提高林区农民收入,处理好林业的经济效益与生态效益之间的关系,提高林业生产力,建立好林业产业体系等。  相似文献   

14.
The “Gadgil effect” hypothesizes that root associations may slow down decomposition through pre‐emptive competition. In the context of recalcitrant litter decomposition, specifically coarse wood debris, it is uncertain as to what is the relative importance of soil communities associated with living roots when compared to those without roots. Here, it is hypothesized that the presence of live roots and active photosynthates will enhance wood decomposition. To test this hypothesis, the presence or absence of temperate tree roots was used in this study. Sugar maple (Acer saccharum) and white oak (Quercus alba) roots were manipulated at three sites of either limestone or shale parent rock residuum. At each site, wood substrate was placed in soils beneath the canopy of either A. saccharum or Q. alba, while in the presence of roots (root+). At the same time, wood substrate was placed in the same soil community, but live root exposure was eliminated by trenching (root?). This eliminated active photosynthate supply to the soil microbial community. Results determined that live root exposure promoted faster decomposition and greater mycelial colonization of wood substrate. Also, sites of shale parent rock residuum had higher rates of decomposition in comparison with limestone parent rock residuum. Although additional work is needed to determine the extent in which roots and lithology can facilitate wood decomposition, these findings suggest that living roots impact decomposers and provide a pathway towards humus and soil organic matter formation.  相似文献   

15.
农林复合经营土壤养分变异的研究   总被引:4,自引:0,他引:4  
农林间作是提高林地生产力水平的重要措施。通过对土壤养分变异的研究,认为幼林期农林养分的竞争较小,选择适宜的间作品种有利于改善土壤的养分状况。豆科作物以改善土壤速效性氮、降低磷的含量为特征;谷类作物能较全面的改善土壤的养分含量;西瓜种植改善土壤的有机质、速效性氮和速效性磷,但肥效持续的时间较短。  相似文献   

16.
The concepts of Multiple‐use forestry and preservation of “virgin”; coniferous forests are elements of an ongoing debate in Norway, regarding aesthetical and biological consequences of current forest management practices. A study, based on the Contingent Valuation Method (CVM), was performed during the fall of 1990. Data were collected through in‐person interviews of 1204 persons above 15 years of age.

The main objectives of the study were to analyze: 1) Attitudes toward the present state of Norwegian forests, 2) Attitudes toward and maximum willingness to pay for changes in current forest management, 3) Preferences and maximum willingness to pay for preservation of “virgin”; coniferous forests, and 4) Attitudes toward society's right to impose restrictions on forest management on private forest land.

Based on responses to statements related to the forest area people usually visit, the study showed a low degree of conflict regarding the present state of Norwegian forests. A ranking of possible results of two alternative forest management strategies, i.e. 1) a more cautious forest management or 2) preservation of “virgin”; coniferous forests, gave the highest average scores to “Preservation of endangered plants and animals”; and “Preservation of “virgin”; forests for our descendants”;, both related to the second management strategy. The maximum willingness to pay for a more cautious forest management was 277 Norwegian kroner (NOK) per household and year, with a median value of NOK 50. 47% of the sample preferred the preservation alternative A specified by the governmental committee, Barskogutvalget, while 18% preferred alternative B and 9% preferred alternative C, corresponding to the governmental decision. 15% preferred a 0‐alternative, i.e. no further preservation of “virgin”; coniferous forests. Two possible sources of bias, related to the CVM, were tested.  相似文献   

17.
There are many log and wood properties of interest to wood processors. There is also high variability in important attributes between and within growing regions and between and within individual stems which influence financial returns to wood processors. This review summarises recent studies of segregation technologies and techniques which have shown that:
  • regional or stand level attribute models will facilitate a coarse level of segregation but not account well for the between and within stem variation;

  • many tools and techniques are available for segregating wood based on internal properties but few have been implemented commercially. Some are better suited for application in mills than in forests;

  • the benefits of segregating stands, stems and logs based on wood properties are not clear due to high variability in wood properties, poor market signals (in terms of price) for wood with superior properties, and poor understanding of the costs across the value chain; and

  • most of the existing economic models tend to look at the economics of segregation from the perspective of a single participant in the value chain, e.g. a structural mill or a central processing yard. Only a few models look across the value chain and these have limitations often poorly representing some participants in the value chain.

  相似文献   

18.
Abstract

Despite a large literature that addresses the gendered structure of forestry occupations in Europe and the USA, relatively little attention has been paid to these issues in Canada. In this paper, it is argued that policy makers and academics have used outdated statistics about forestry employment to shape policies and programs of government and industry. Use of these data has been to the general disadvantage of women working in the forest industry and in forestry communities. This paper draws mainly on three studies, spanning the mid-1990s to the mid-2000s. Each study relied on secondary sources such as Census data, government and industry documents, as well as primary sources such as interviews or questionnaires. On Vancouver Island, British Columbia, analysis of land reallocation policies and transition strategies for displaced workers in the 1990s did not consider women as forestry workers or consider how job losses and opportunities for retraining might vary between men and women. Consequently, gender-neutral transition strategies were more accessible for men than for women. A study of female forestry workers in Saskatchewan revealed there was very little knowledge about employment conditions for women in forestry. Women reported that they missed out on training and advancement opportunities because they lacked networks, childcare support or other benefits that might encourage them to improve their circumstances. Finally, a survey of forest sector advisory committees across the country revealed a very low rate of participation by women, even though those who did participate had some significantly different viewpoints about forestry than their male counterparts. In combination, these efforts suggest that improvements in the understanding of forestry employment would benefit forestry workers, both male and female, and ensure that all workers made lasting contributions to the industry.  相似文献   

19.
The purpose of this paper is to estimate the environmental value of recycled wood wastes using conjoint analysis. Conjoint analysis is one of many multi-attribute preference-elicitation techniques widely used in market research. A comparison of the pair-wise rating method and the choice experiment elicitation method is made. An empirical study estimates the value of recycled water cleaners using pair-wise rating and choice experiments. Water cleaners have many attributes, including their cleaning performance, replacement time, size, color, and price. Existing water-cleaning filters use propylene or polyethylene, which are made from petroleum resources. These filters become waste after being replaced. Another type of water-cleaning filter is being developed, known as a “recycled filter,” which is made from construction industry wood wastes and logs from thinning. This recycled filter can subsequently be dissolved by bacteria. An empirical study of recycled water-cleaning filters made from wood wastes shows that recycling has significant value as estimated by both pair-wise rating and choice experiments. However, the estimated marginal willingness to pay for recycling differs between the two methods. It may be that profile design effects appear in our survey.  相似文献   

20.
In many countries, forestry associations represent an important forest policy tool for overcoming the problems that often arise with small forest ownership. In Germany associations are established for economic reasons as well as for reasons pertaining to governance. For over 100 years there has been discussion concerning the suitability of various organisational models. Of the wide spectrum of possible organisational forms, only a few variants have been used as of late. These are often accredited as being inefficient with regard to the extent to which they fulfil their intended functions. This paper researches the reasons for various assumptions made of neo-institutionalism with regard to the establishment and survival of forestry associations. The analysis is based on public and scientific debate of this topic. It gives an overview of the political discussion that has taken place over the last few decades as well as the current state of related scientific literature. It can be shown that, aside from issues related to the efficiency of associations in the fulfilment of duties, the impact that associations have with regard to legitimising the engagement of other actors and their supply of resources is also relevant.  相似文献   

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