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指出了社会犯罪问题日益严重,居民对于安全的需求日益凸显。基于CPTED理论的研究,分析了居住区空间在安全防卫方面存在的问题,并提出了相应的居住环境设计预防策略。  相似文献   

3.
Biochar is normally produced as a by-product of bioenergy. However, if biochar is produced as a co-product with bioenergy from sustainably managed forests and used for soil amendment, it could pro- vide a carbon neutral or even carbon negative solution for current envi- ronmental degradation problems. In this paper, we present a comprehen- sive review of biochar production as a co-product of bioenergy and its implications. We focus on biochar production with reference to biomass availability and sustainability and on bioehar utilization for its soil amendment and greenhouse gas emissions reduction properties. Past studies confirm that northwestern Ontario has a sustainable and sufficient supply of biomass feedstock that can be used to produce bioenergy, with biochar as a co-product that can replace fossil fuel consumption, increase soil productivity and sequester carbon in the long run. For the next step, we recommend that comprehensive life cycle assessment of bio- char-based bioenergy production, from raw material collection to bioehar application, with an extensive economic assessment is necessary for making this technology commercially viable in northwestern Ontario.  相似文献   

4.
龙竹适生性及产量预测初步研究   总被引:1,自引:0,他引:1  
通过典型抽样调查,利用单因素分析方法得出龙竹的适生海拔、坡位、坡向.并实测了32株龙竹的胸径和重量,根据胸径和重量的相关性,首次推导出了龙竹的产量预测模型;为造纸企业科学合理的经营龙竹原料林起到促进作用.  相似文献   

5.
Second-generation biofuels are often seen as essential element in the future bioeconomy strategy. Countries with extensive forest resources such as Norway often view wood as preferred bio-feedstock, yet the effects of wood demand on assortments of harvested wood and other wood-based industries are unclear. Focusing on the importance of feedstock choice, we analyse the impacts of establishing a second-generation medium-scale biofuel plant in Norway. For the analysis, a dynamic forest sector model where the choice of tree species, wood assortments, production of bioenergy, and forest industry products are explicitly included, was applied. We find the optimal biofuel feedstock mix to be dominated by softwood chips from pulpwood comprising 48% of total biomass inputs in 2030 and increasing to 67% by 2055, followed by hardwood chips from birch, comprising initially 34% of total biomass inputs and 16% by 2055. The proportion of harvest residues remained constant at about 18% over time and roundwood was not used at all for biofuel production. Despite the additional demand for chips, the single medium-scale biofuel plant will have only minor effects on existing forest industries and harvests in Norway, as the domestic impact is dampened by changes in foreign trade flows, especially of chips.  相似文献   

6.
The use of forest biomass as a renewable energy source has received much attention as a response to climate change and the increasing global demands for energy. Local availability and conversion into secondary energy carriers with a lower capital investment shows more weights on its interests. The substitution of fossil fuel by biomass fuel can have a strong effect on the mitigation of climate change through reducing greenhouse gases, which can be an important consideration for CDM projects in Bangladesh. This study uses literature review to analyse the legal framework of carbon trading under CDM, CDM additionality, CDM and bioenergy promotion, land availability and technology for biomass production, and sustainability of CDM projects in Bangladesh. The barriers to CDM projects in Bangladesh are explained as well as measures for promoting biomass production. Biomass and bioenergy-based CDM projects can be attractive and support sustainable development in Bangladesh. The study suggests capacity building and policy changes needed in order to comply with CDM modalities. The study can be useful to the climate change mitigation and development policy makers in Bangladesh.  相似文献   

7.
Wood from three tree species was used for making slow-releasing woodchip fertilizer. Fertilizer made from Populus tomen-tiglandulosa retained the highest amounts of N (29.04%), P2O5 (26.03%) and K2O (16.93%). On the other hand, woodchip fertilizer made from Pinus koraiensis retained the lowest amounts of N (26.22%), P2O5 (21.80%) and K2O (14.49%). A field experiment was performed in a 50 m2 experimental plot at Gangwon Agricultural Research and Extension Services, Chuncheon, Korea from August to November 1999. The effects of a general fertilizer along with compost and slow releasing woodchip fertilizer without compost on the cabbage production were observed. Cabbage production parameters, such as top height, head weight, head height, head width, number of outer and inner leaves, leaf width and head length, increased in the field where Larix kaempferi woodchip fertilizer was added as a basal dose. The result showed that the woodchip fertilizer made from Pinus koraiensis had faster releasing properties compared to other woodchip fertilizers. Without adding any compost in the woodchip fertilized field, woodchip fertilizer showed a superior outcome over a general chemical fertilizer. Although the amount of woodchip fertilizer was larger compared to that of a chemical fertilizer, it increased cabbage production.  相似文献   

8.
Increased forest biomass production for bioenergy will have various consequences for landscape scenery, depending on both the landscape features present and the character and intensity of the silvicultural and harvesting methods used. We review forest preference research carried out in Finland, Sweden and Norway, and discuss these findings in relation to bioenergy production in boreal forest ecosystems. Some production methods and related operations incur negative reactions among the public, e.g. stump harvesting, dense plantation, soil preparation, road construction, the use of non-native species, and partly also harvest of current non-productive forests. Positive visual effects of bioenergy production tend to be linked to harvesting methods such as tending, thinning, selective logging and residue harvesting that enhance both stand and landscape openness, and visual and physical accessibility. Relatively large differences in findings between studies underline the importance of local contextual knowledge about landscape values and how people use the particular landscape where different forms of bioenergy production will occur. This scientific knowledge may be used to formulate guiding principles for visual management of boreal forest bioenergy landscapes.  相似文献   

9.
毛竹笋材两用林丰产结构的初步研究   总被引:5,自引:3,他引:2  
对宜溧山区和宁镇丘陵区毛竹笋材两用林定点观测研究表明;(1)廊的林分结构是竹林丰产的关键。以产笋为主、产竹为辅的毛竹笋材两用林丰产结构为每公顷立竹2700~330支,胸径〉9.0cm,年龄组成应保护1~3度竹,各龄级比例为1:1:1,笔直林产量(竹材、竹笋)高。以产竹为主、产笋为辅的毛竹材笋两用林丰产结构为每公立竹2700~3600支,胸径9.0cm,年龄组成应保留1~4度竹,各龄级比例为3:3:  相似文献   

10.
Abstract

Consumers in today's world can perceive an additional benefit associated with responsible business practices and the sustainability of purchased products. However, in Scandinavian context, there is a lack of knowledge of consumer perceptions toward environmental and social sustainability of wood products. Our data on adult Finnish consumers (private end-users) (N=227) were collected during 2004–2007 as interview exit data from home retail centers selling building materials. The perceived environmental and social sustainability of wood products was investigated using exploratory factor analysis, and the phenomenon was observed to be a two-dimensional construct consisting of “General environmental and social sustainability” and “Specific social sustainability” reflecting strong consumer need for product safety. Logistic regression analysis revealed that the “General” dimension also explains the consumer's self-declared willingness to pay for sustainable wood products. The results also indicate that the respondents may be segmented based on their perceptions on product level environmental and social sustainability: the most environmentally and socially conscious group can be profiled by gender (female), older age, and summer cottage ownership.  相似文献   

11.
邹莉  许继飞  王向利  郑红 《林业研究》2005,16(2):161-162
本文采用自然沉降平板法,对哈尔滨市某木材厂空气微生物种类和数量进行测定.结果表明:未经空气净化器处理的木材生产车间中的空气微生物数量(54939 cfu(m-3)是经空气净化器处理(25768 cfu(m-3)的2.1倍.空气净化器虽然能够净化生产车间中的空气微生物,但其净化率为53.1%,净化后的空气未达到洁净空气的标准,因此还应同时采取其他相应净化措施.净化器可以显著降低空气中放线菌的数量,尤其能够完全清除放线菌,如:疮痂类群(Scabies), 烬灰类群(Cinereas)和吸水类群(Hygroscopicas),但对细菌和真菌效果不明显.建议今后采用更有效可行的方法来净化木材生产车间中的空气微生物.  相似文献   

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Tower yarders have recently been introduced to forestry in Turkey. Clarification of the productivity and cost of logging using the tower yarder is often requested because the cost for machinery is a significant factor in all calculations concerning mechanized operations. Machines are often extremely expensive compared with the low cost of labor in developing regions. In this study, a new logging system using a tower yarder was compared with a conventional system using a stationary yarder in terms of productivity and cost. The research was conducted in the northeast of Turkey, in 1989 and 1992. The productivity of the tower yarder and the stationary yarder was found to be 5.655 m3/h and 5.002 m3/h, respectively. Harvesting cost was analyzed based on observed productivity. The harvesting costs of the tower yarder and the stationary yarder were found to be 47,410 TL/m3 and 17,553 TL/m3, respectively. With the tower yarder, the machine cost reached 93.1 % of the harvesting cost while the machine cost using the stationary yarder reached 71.1%. A part of this paper was orally presented at the 3rd Annual Meeting of the Japan Forest Engineering Society (1996).  相似文献   

15.
Glyphosate is the herbicide most extensively used for site preparation and conifer release. It is a broadspectrum herbicide and therefore crop safety is a critical issue. This study assessed the early effects of 14 different treatments, including no weed control, manual weed control, and 12 foliar-applied herbicide treatments at low,intermediate, high, and highest application rates and application timing on glyphosate phytotoxicity of containerized seedlings of Austrian pine(Pinus nigra J.F.Arnold.), Scots pine(P. sylvestris L.) and maritime pine(P.pinaster Aiton), conifer species widely used for afforestation and supplementary plantings in Turkish forestry. In general, Scots pine seedlings were tolerant to glyphosate compared to the other species. Glyphosate phytotoxicity varied significantly according to the time and rate of application. Seedlings were relatively tolerant to glyphosate in April whereas they were intolerant in May. The highest herbicide rate(1.2% v:v) was consistently phytotoxic to all species. Moreover, the effect of herbicide rate on seedling survival and growth varied significantly according to application date(i.e., application rate 9 date interaction). Seedlings appeared tolerant to glyphosate at low and intermediate rates(0.2, 0.4% v:v) between midspring and mid-summer, whereas they demonstrated significant sensitivity to the highest rate across all time periods. Glyphosate at the high rate(0.8% v:v) was particularly more phytotoxic when applied in May. Application of glyphosate at rates up to 0.8% could be recommended for weed control without significant pine damage in midspring when the needles presumably have a dense leaf epicuticular wax layer limiting herbicide penetration.Applications of 0.8 and 1.2% v:v are not recommended during May–June.  相似文献   

16.
ABSTRACT

Soil erosion is a major socioeconomic and environmental problem in Turkey. Almost 86% of the land in Turkey has suffered various degrees of soil erosion. The objective of this study was to determine whether differences in tree species affect soil characteristics and microbial activity in degraded soils. Results from this study showed that organic C (Corg) was highest in the black locust soil at 0–20 cm depth and lowest in the bare land. Microbial biomass C (Cmic) increased in the order black locust > Scotch pine > bare land at two soil depths. One-way ANOVA demonstrated that afforested soils contain significantly higher microbial biomass C than those in the bare land soils. Microbial quotient (Cmic/Corg) of soils are positively influenced by afforestation as the bare land soils exhibited lower microbial quotient than the associated Scotch pine and black locust soils. Microbial communities in black locust soils were energetically more efficient—had a lower metabolic quotient (qCO2)—with a higher Cmic/Corg compared to those in Scotch pine soils. However, the microbial quotient in our study was still below range and cannot reach equilibrium again 15 yr after afforestation. Restoration of degraded lands could be a long-term process from microbial activity in the observed regions.  相似文献   

17.
Sunila ES  Kuttan G 《Fitoterapia》2005,76(7-8):649-655
The radioprotective property of an ethanolic extract of Piper longum fruits (EEPLF) was investigated in Swiss mice. The white blood cell (WBC) count in irradiated control mice was drastically reduced to 1900 cells/mm3 on third day but in treated animals the count was 2783.3 cells/mm3. The number of bone marrow cells and alpha-esterase positive cells was also enhanced by the EEPLF administration (16.7 x 10(6) cells/femur and 946.5/4000 cells, respectively) when compared to the radiation exposed control animals (12.2 x 10(6) cells/femur and 693.5/4000 cells, respectively). EEPLF reduced the elevated levels of glutathione pyruvate transaminase (GPT), alkaline phosphatase (ALP), and lipid peroxidation (LPO) in liver and serum of radiation treated animals. The extract administration also increased the reduced glutathione (GSH) production to offer the radioprotection.  相似文献   

18.
Incentive design is among the decisive factors behind active community participation and long-term sustainability of participatory forest management. Especially in case of mangroves, where multiple interests apply, it requires a careful integration of several ecological, economic and institutional factors. The primary objective of this paper is to understand the basis of incentive design and make a comprehensive inquiry into the existing incentive mechanism of participatory mangrove management in Indian Sundarbans. The qualitative and in-depth assessment was derived against a conceptual framework that contains three main determinants: (1) resources availability, (2) control mechanism, and (3) perception of end-users. The study deploys the results of various participatory exercises such as structured interviews with forest officials, focus group discussions with 10 Joint Forest Management Committees and semi-structured interviews with 119 mangrove users. In general, we observed an over-cautious, hierarchical and safety-margin-based incentive design with distinct bifurcation of communities over the adequacy and effectiveness of derived benefits. Although, the incentives are diverse and align well with the overall conservation of mangroves, they are considered to be insufficient by nearly half of the mangrove users. The main issues that were observed to hinder effective community participation can be summarized as (1) serious restrictions on access to economically exploitable mangrove products, (2) passive involvement of vulnerable occupational groups, and (3) lack of trust and conflicting interests between the officials and the communities. Although the existing preventive management of mangroves can be justified considering the magnanimity of the Indian Sundarbans, it can severely impair community participation and emerge as a clear threat to future sustainability. To secure greater participation of the communities, we propose small scale, innovative developmental incentives to supplement traditional forest-resource-based incentives.  相似文献   

19.
A deterministic dynamic bio-economic model was used to analyse different management options for goats and charcoal production in a forest in Zagros, Iran. The study sought optimal management options from a local community point of view considering net present value (NPV) of income from sale of goats and charcoal under different restrictions on forest harvest imposed by the state. The model was run under six model scenarios: (1) business as usual (BAU), (2) no state intervention, (3) no forest harvesting, (4) strict quota, (5) medium quota and (6) loose quota on charcoal production. The scenarios' results were compared based on four numeric criteria (NPV of income from goats and charcoal, development of standing volume and tree size diversity in forest, interaction between goat population and oak forests) and one subjective criterion (state budget for managing forest). The results indicated that two main challenges exist in forest management in Zagros; (1) to determine the balance between local communities' welfare and biological stability of the forest and (2) to choose between a cheap management regime prohibiting wood harvest but implicitly accepting some illegal charcoal production and a more expensive, but legal, harvest regulation through charcoal production quota. We conclude that the BAU scenario, where forest harvesting was prohibited de jure, but some illegal charcoal production was still undertaken, was the only viable management, which also is practically acceptable by both state and local communities.  相似文献   

20.

Context

Forest structure characterisation approaches using LiDAR data and object-based image analysis remain scarce to forestry agencies as these automated procedures usually require the use of expensive software and highly skilled analysts. The integration of forest expert opinion into semi-automated approaches would simplify the access of forest managers to new technologies and would allow the incorporation of personal experience and the introduction of specific forest management criteria.

Aim

The aim of this study is to explore new alternatives to a previously published automated approach based on LiDAR data and object-based image analysis.

Methods

We compare four approaches, ranging from null to high incorporation of expert opinion and from fully automated to fully manual. These four approaches consist of three stages: (1) forest stand identification from LiDAR models, (2) forest stand classification into forest structure classes (manual and based on cluster analysis), and (3) validation.

Results

Quantitative attributes for validation (i.e. hypsographs and percentiles) provided slightly lower degree of separability for forest structure classes, in the mixed procedures with increasing incorporation of expert opinion than for the fully automated approach.

Conclusions

The new mixed approaches proposed are comparable to the automated procedures for the characterisation of forest structure in heterogeneous pine forest stands. They also offer additional advantages: (1) they make it possible to give a specific management focus and (2) they provide accessibility by the forest managers to the source of LiDAR information.  相似文献   

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