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1.
2.
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.
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   

5.
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   

6.
毛竹笋材两用林丰产结构的初步研究   总被引:2,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   

7.
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   

8.
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   

9.
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   

10.
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   

11.
本文从林业可持续发展的战略思想出发,结合国情、省情、林情,提出了因林制宜搞好森林分类的思想,并提出了对分类经营、分类指导、分类系统和分类技术、分类调整、分类经营与森林资源调查、规划设计相关技术措施、技术标准进行调整的思路和想法。  相似文献   

12.
匍枝委陵菜引种驯化试验   总被引:4,自引:0,他引:4  
匍枝委陵菜(Potentilla flagellaris Willd.ex Schlecht. ),又名蔓委陵菜、鸡头儿苗,为蔷薇科委陵菜属植物.分布于黑龙江、山东、山西、河北、甘肃、江苏,朝鲜、蒙古及俄罗斯西伯利亚地区也有分布.本文研究了野生地被植物匍枝委陵菜的生物学和生态学特性、物候特点、繁殖规律及开发利用价值.结果表明,匍枝委陵菜具有广泛的适应性和较强的抗逆性,生长快,繁殖力强,成坪时间短,绿期长,既可观叶又可观花,管理粗放,养护费用低,通过驯化和开发,可广泛应用于城市园林和绿化.  相似文献   

13.
The results of the clinical assessment of a multiherbal indigenous formulation on 22 patients with bleeding piles are reported.  相似文献   

14.
  • ? This contribution presents a dynamic stand growth model for Beech (Fagus sylvatica L.) forests, based on a dataset provided by the Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Birmensdorf. The dataset includes 143 research plots, covering a wide range of growing sites and providing up to 16 interval measurements per research plot.
  • ? The objective of this research is to complement the range of existing beech growth models by bridging the gap between the historical yield tables and the single tree growth models. The specific aim is to develop transition functions which will project three state variables (dominant height, basal area and number of trees per hectare) at any particular time, in response to any arbitrary silvicultural treatment.
  • ? Two of the transition functions were derived using the generalized algebraic difference approach (GADA), the third one was derived with the algebraic difference approach (ADA). All the functions were fitted simultaneously using iterative seemingly unrelated regression and a base-age-invariant method. The influence of thinnings on basal area growth was included by fitting different transition functions for thinned and unthinned stands.
  • ? The overall model provides satisfactory predictions for time intervals up to 20 years. The new model is robust and its relatively simple structure makes it suitable for economic analysis and decision support.
  •   相似文献   

    15.
    根据城市道路的环境特点,提出了城市道路绿化植物(包括乔木、灌木、地被植物、草本花卉)的一般选择标准和配置形式。  相似文献   

    16.
    The use of land for intensive arable production in Europe is associated with a range of externalities that typically impose costs on third parties. The introduction of trees in arable systems can potentially be used to reduce these costs. This paper assesses the profitability and environmental externalities of a silvoarable agroforestry system, and compares this with the profitability and environmental externalities from an arable system and a forestry system. A silvoarable experimental plot of poplar trees planted in 1992 in Bedfordshire, Eastern England, was used as a case study. The Yield-SAFE model was used to simulate the growth and yields of the silvoarable, arable, and forestry land uses along with the associated environmental externalities, including carbon sequestration, greenhouse gas emissions, nitrogen and phosphorus surplus, and soil erosion losses by water. The Farm-SAFE model was then used to quantify the monetary value of these effects. The study assesses both the financial profitability from a farmer perspective and the economic benefit from a societal perspective. The arable option was the most financially profitable system followed by the silvoarable system and forestry. However, when the environmental externalities were included, silvoarable agroforestry provided the greatest benefit. This suggests that the appropriate integration of trees in arable land can provide greater well-being benefits to society overall, than arable farming without trees, or forestry systems on their own.  相似文献   

    17.
    为了掌握河南省柿种质资源的发展现状,采用室外调查与文献查阅、样本检测相结合的方法,于2011—2014年对河南省柿主栽区洛阳市、平顶山市、郑州市等6个地区的11个县(区)的柿种质资源进行了调查研究。结果表明:河南省至少有70个地方品种;各地普遍存在同名异物或同物异名的现象,其果实、花、叶片、枝条等性状均呈现出丰富的多样性,其数量性状的变异系数为0.14~0.60,说明其变异程度较高;按果实形状和成熟期等不同标准可以分为不同类别;河南省涩柿代表品种有新安牛心柿、博爱八月黄、荥阳水柿、平顶山灰柿、黑柿等品种。  相似文献   

    18.
    Twelve-week-old container-grown seedlings of noble fir (Abies procera Rehd.) and Shasta red fir (A. magnifica A. Murr. var. shastensis Lemm.), both high-elevation species, were grown under controlled environments in a study of induction of terminal-bud dormancy. Eight treatment combinations of long (15 h) or short (11 h) photoperiods, warm (25°/20°C) or cool (18°/12°C) thermoperiods, and dry (–1.2 MPa) or wet (–0.6 MPa) moisture regimes were imposed upon seedlings for 12 weeks. Treatment factors significantly affecting the induction of dormancy in terminal buds of seedlings were identified over time. The results suggest that seedlings responded dynamically to dormancy cues. The warm/dry and cool/wet combinations induced dormancy in the first 2 weeks in noble fir and in the first week in Shasta red fir. Short-day/warm and long-day/cool combinations enhanced dormancy induction in weeks 3 to 4 in noble fir and in weeks 1 to 7 in Shasta red fir. Short days and cool thermoperiods independently hastened dormancy induction in noble fir in weeks 5 through 12.  相似文献   

    19.
    Abstract

    It is commonly accepted in the analysis of wood beams that the neutral axis coincides with the beam's centroid. However, wood is not an isotropic material, has different elastic properties in the tangential, radial and longitudinal directions, and is non-homogeneous, as it contains characteristics such as knots. Therefore, there is need for an analysis of the neutral axis for anisotropic, non-homogeneous materials, such as wood, to predict deformations and strains. Specifically, digital imaging correlation, a non-contact technique to measure deformation of an object's surface, is used to examine how knots influence neutral axis location. Output from digital imaging correlation software provides a clear image of the location of the neutral axis. The neutral axis in a clear wood beam remains close to the centroidal axis throughout loading, while the location of a knot determines the size of the compression and tension zones as well as the location of the neutral axis.  相似文献   

    20.
    Chestnut plantations for fruit production in Northern Portugal have been subjected to intensive management system, including soil tillage, mineral fertilization and pruning. Some of these practices have no positive effect on productivity and soil–plant–water relations. Other systems (e.g., no tillage with maintenance of grass cover) have been adopted, aiming a multifunctional land use, exploiting nuts, pasture and edible mushrooms. Thus, an experimental trial was installed to assess the effects of such systems on productivity, sustainability and annual net income, as compared with the conventional system, over a six-year period. The treatments were: conventional soil tillage (CT); no tillage with permanent spontaneous herbaceous vegetation cover (NV); no tillage with permanent rainfed seeded pasture cover (NP); and as NP but with irrigation (NIP). Production of nuts, forage and edible mushrooms were measured and sustainability was assessed by production and diversity of fungal sporocarps. Annual net income was estimated by the difference between the annual gross outputs (market values for nuts, forage and edible commercial mushrooms) and the annual input costs. The greatest nut and edible mushroom production and sporocarp biodiversity were achieved in the NIP and NV and the smallest in the CT treatment. The highest annual gross output was estimated for the NV and NIP treatments, whereas the highest annual net income was obtained for the NV. No tillage with maintenance of spontaneous grass cover showed to be the most favourable management system, as it has increased productivity and biodiversity.  相似文献   

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