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101.
本文阐述了林业资源多媒体信息管理系统的开发环境、组织结构和功能.  相似文献   
102.
生物炭技术缓解我国温室效应潜力初步评估   总被引:9,自引:2,他引:9  
姜志翔  郑浩  李锋民  王震宇 《环境科学》2013,34(6):2486-2492
热解制备的生物炭在实现了将植物吸收的大气CO2封存在土壤中的同时,还将产生多重农业生产效应.在调查我国农林废弃物资源可利用潜力的基础上,利用生命周期评价(life cycle assessment,LCA)方法对热解生物炭技术在缓解温室效应方面的潜力进行了初步评估.研究表明,我国每年可供生物炭生产的农林生物质资源总量为6.04×108t;温室效应净潜力(以CO2e计,CO2e为CO2当量)为5.32×108t,相当于每t原料可封存0.88 t.在整个温室效应潜力中,贡献最大的是大气CO2以生物炭形式在土壤中的封存,约为73.94%,其次是副产物可更新能源生产所产生的温室效应潜力,占总潜力的23.85%.由此可见,以农林废弃生物质资源为原料热解制备生物炭的技术对于缓解我国严峻的温室气体排放压力具有巨大的潜力.  相似文献   
103.
Forests cover approximately one‐third of Central Europe. Oak (Quercus) and European beech (Fagus sylvatica) are considered the natural dominants at low and middle elevations, respectively. Many coniferous forests (especially of Picea abies) occur primarily at midelevations, but these are thought to have resulted from forestry plantations planted over the past 200 years. Nature conservation and forestry policy seek to promote broadleaved trees over conifers. However, there are discrepancies between conservation guidelines (included in Natura 2000) and historical and palaeoecological data with regard to the distribution of conifers. Our aim was to bring new evidence to the debate on the conservation of conifers versus broadleaved trees at midelevations in Central Europe. We created a vegetation and land‐cover model based on pollen data for a highland area of 11,300 km2 in the Czech Republic and assessed tree species composition in the forests before the onset of modern forestry based on 18th‐century archival sources. Conifers dominated the study region throughout the entire Holocene (approximately 40–60% of the area). Broadleaved trees were present in a much smaller area than envisaged by current ideas of natural vegetation. Rather than casting doubt on the principles of Central European nature conservation in general, our results highlight the necessity of detailed regional investigations and the importance of historical data in challenging established notions on the natural distribution of tree species.  相似文献   
104.
Cambodia has 57% forest cover, the second highest in the Greater Mekong region, and a high deforestation rate (1.2%/year, 2005–2010). Community forestry (CF) has been proposed as a way to reduce deforestation and support livelihoods through local management of forests. CF is expanding rapidly in Cambodia. The National Forests Program aims to designate one million hectares of forest to CF by 2030. However, the effectiveness of CF in conservation is not clear due to a global lack of controlled comparisons, multiple meanings of CF, and the context‐specific nature of CF implementation. We assessed the effectiveness of CF by comparing 9 CF sites with paired controls in state production forest in the area of Prey Long forest, Cambodia. We assessed forest condition in 18–20 randomly placed variable‐radius plots and fixed‐area regeneration plots. We surveyed 10% of households in each of the 9 CF villages to determine the proportion that used forest products, as a measure of household dependence on the forest. CF sites had fewer signs of anthropogenic damage (cut stems, stumps, and burned trees), higher aboveground biomass, more regenerating stems, and reduced canopy openness than control areas. Abundance of economically valuable species, however, was higher in control sites. We used survey results and geographic parameters to model factors affecting CF outcomes. Interaction between management type, CF or control, and forest dependence indicated that CF was more effective in cases where the community relied on forest products for subsistence use and income. Efectividad de la Silvicultura Comunal en el Bosque Prey Long, Camboya  相似文献   
105.
Because of concerns with the growing threat of global climate change from increasing emissions of greenhouse gases, the United States and other countries are implementing, by themselves or in cooperation with one or more other nations, climate change projects. These projects will reduce greenhouse gas (GHG) emissions or sequester carbon, and will also result in non-GHG benefits (i.e., environmental, economic, and social benefits). Monitoring, evaluating, reporting, and verifying (MERV) guidelines are needed for these projects to accurately determine their net GHG, and other, benefits. Implementation of MERV guidelines is also intended to: (1) increase the reliability of data for estimating GHG benefits; (2) provide real-time data so that mid-course corrections can be made; (3) introduce consistency and transparency across project types and reporters; and (4) enhance the credibility of the projects with stakeholders. In this paper, we review the issues involved in MERV activities. We identify several topics that future protocols and guidelines need to address, such as: (1) establishing a credible baseline; (2) accounting for impacts outside project boundaries through leakage; (3) net GHG reductions and other benefits; (4) precision of measurement; (5) MERV frequency and the persistence (sustainability) of savings, emissions reduction, and carbon sequestration; (6) reporting by multiple project participants; (7) verification of GHG reduction credits; (8) uncertainty and risk; (9) institutional capacity in conducting MERV; and (10) the cost of MERV.  相似文献   
106.
进入二十一世纪 ,环境问题越来越受到人们的重视 ,人口密集、污染严重的城市环境更是人们关注的焦点。城市林业建设可以防止城市环境污染 ,改善城市环境。城市林业包括城市园林 ,它的范围要比园林建设广泛 ,它的理想状态应是一个有调控作用的生态系统 ,达到森林、城市、人类的和谐统一。因此 ,在城市建设中要重视城市林业 ,大力发展城市林业 ,使我们的工作和生活环境更加舒适  相似文献   
107.
The study of effects of acid rain in Southwestern China on forest ecosystems .has been inrestigated since 1984. The results have shown that the ecosystem of Pinus massoniana forest has been damaged severely by acid rain. Comparing the areas where the annual mean pH value is lower than 4.5 with that higher than 4.5, the productivity of the ecosystems decreased 50 percent. Both the percentages of the green leaves and the content of chlorophyll cut down; the acidity of soil increased a bit and the fertility showed the tendency to lower. The microbial population components in surface soil were changed and the total number of soil microbes reduced from 63.5 to 92.6 percent. Besides the direct effects of acid rain, the insect pest, especially, Blastophagus piniperdoz and Monochamus galloprovincialis, seized the opportunity to enter and reproduce in it so as to aggravate the forest dieback of P.massoniana in the areas where the annual average pH value is lower than 4.5.Additionally, the simulation study on the  相似文献   
108.
本文通过林业建设环境分析、论证,提出一江两河地区综合防护林体系建设的战略构想:在认真保护、科学经营现有森林资源的基础上,以拉萨河、雅鲁藏布江中段、年楚河谷地为主线,重点建设沿江防护林带,构成防护林体系的主要骨架;在河谷农田草场加速防护林网建设,完成防护林体系的网络结构;依土地条件积极营造薪炭林,适当发展用材林和四旁植树(含林卡和经济果树等),完善防护林体系的带网片结,建立起我国高原最大的综合防护林体系,保护好地理环境独特的高寒农业区和“世界第三极”。  相似文献   
109.
湘南地区天草主要病虫害发生特点及综合防治   总被引:1,自引:0,他引:1  
天草主要病害有炭疽病、煤烟病、日灼病和缺素症,主要害螨害虫有红蜘蛛、锈壁虱、蚜虫、潜叶蛾、柑桔象虫类、柑桔凤蝶和介壳虫类.文章总结了这些主要病虫害在天草上发生特点、时期及防治方法.  相似文献   
110.
广州市城市林业管理信息系统的研制开发   总被引:4,自引:0,他引:4  
将GIS技术引进技术林业研究,建立广州市城市林业管理信息系统,该系统具有采集,管理,分析和更新多种区域空间信息的能力,其分六个子系统,公园管理子系统,绿地管理子系统、市郊森林管理子系统、管理机构管理子系统,法规文件管理子系统。可以文字,数据,报表,图形,录像和声音等方式输入、存储、显示、输出绿化系统各类信息,并能随时查阅,检索、修改、录入、删除各类信息。  相似文献   
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