中国森林资源可持续发展问题的探讨

森林资源的可持续发展是林业和国家经济、社会、环境协调发展的基础。为使森林资源可持续发展战略建立在坚实的基础上，本文论述了森林资源可持续发展的优势所在，探讨了我国森林资源发展中存在的问题，分析了产生问题的原因。     

Effects of acid rain on forest ecosystem in Southwestern China

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     

京-秦地区的森林资源及其发展潜力

本文是“京津唐地区（包括秦皇岛市）国土卫星像片在森林资源调查中的应用研究结果的一部分,统计分析了各类森林资源的分布面积和主要特点,并指出其发展潜力,全区现有森林面积计约61.6×10⁴ ha,覆盖率约11％,宜林地面积约86.2×10⁴ ha,覆盖率约15.4％。主要分布于山地。从发展潜力看,可以增加森林覆盖率10％以上,可能提高立木蓄积量和果树产量4—5倍。     

森林保健旅游开发之探讨

生态旅游已成为21世纪世界旅游业的热点,森林旅游被认为是生态旅游的龙头和主体.森林保健旅游则是森林生态旅游的重要发展方向.在对森林保健功能阐析的基础上,提出中国森林保健旅游开发方向与对策.     

试论西藏一江两河地区综合防护林体系建设

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”。     

京—秦地区的森林资源及其发展潜力

本文是“京津唐地区(包括秦皇岛市)国土卫星像片在森林资源调查中的应用研究结果的一部分,统计分析了各类森林资源的分布面积和主要特点,并指出其发展潜力,全区现有森林面积计约61.6×10~4 ha,覆盖率约11％,宜林地面积约86.2×10~4 ha,覆盖率约15.4％。主要分布于山地。从发展潜力看,可以增加森林覆盖率10％以上,可能提高立木蓄积量和果树产量4—5倍。     

黄土高原西部地区林业气候动态聚类分析

杨树是黄土高原的主要树种之一。本文根据阴山东段不同立地条件下25年生的四种杨树解析木生长量资料,与该地区同时期气候因素进行了关联分析,按关联度大小,选取了八个气候因素作为聚类因子,再将关联度归一化,求得各因子的权重,表示各气候因素对树木生长作用的大小。最后根据黄土高原西部68个气象站1951—1980年的气候资料,应用动态聚类分析法,把黄土高原西部地区划分成几个不同类型林业气候区,区划结果与实际考察基本相符合。     

Forest land use change in the philippines and climate change mitigation

Tropical forests in countries like thePhilippines are important sources and sinks of carbon(C). The paper analyzes the contribution of Philippineforests in climate change mitigation. Since the 1500s,deforestation of 20.9 M ha (10⁶ ha) of Philippineforests contributed 3.7 Pg (10¹⁵ g) of C to theatmosphere of which 2.6 Pg were released this century. At present, forest land uses store 1091 Tg(10¹² g) of C and sequester 30.5 Tg C/yr whilereleasing 11.4 Tg C/yr through deforestation andharvesting. In the year 2015, it is expected that thetotal C storage will decline by 8% (1005 Tg) andtotal rate of C sequestration will increase by 17%(35.5 Tg/yr). This trend is due to the decline innatural forest area accompanied by an increase intree plantation area. We have shown that uncertaintyin national C estimates still exists because they arereadily affected by the source of biomass and Cdensity data. Philippine forests can act as C sink by:conserving existing C sinks, expanding C stocks, andsubstituting wood products for fossil fuels. Here weanalyze the possible implications of the provisions ofthe Kyoto Protocol to Philippine forests. Finally, wepresent current research and development efforts ontropical forests and climate change in the Philippinesto improve assessments of their role in the nations Cbudgets.     

Natural formation and degradation of chloroacetic acids and volatile organochlorines in forest soil--challenges to understanding

- DOI: http:/dx.doi.org/10.1065/espr2005.06.262 Goal, Scope and Background The anthropogenic environmental emissions of chloroacetic acids and volatile organochlorines have been under scrutiny in recent years because the two compound groups are suspected to contribute to forest dieback and stratospheric ozone destruction, respectively. The two organochlorine groups are linked because the atmospheric photochemical oxidation of some volatile organochlorine compounds is one source of phytotoxic chloroacetic acids in the environment. Moreover, both groups are produced in higher amounts by natural chlorination of organic matter, e.g. by soil microorganisms, marine macroalgae and salt lake bacteria, and show similar metabolism pathways. Elucidating the origin and fate of these organohalogens is necessary to implement actions to counteract environmental problems caused by these compounds. Main Features While the anthropogenic sources of chloroacetic acids and volatile organochlorines are relatively well-known and within human control, knowledge of relevant natural processes is scarce and fragmented. This article reviews current knowledge on natural formation and degradation processes of chloroacetic acids and volatile organochlorines in forest soils, with particular emphasis on processes in the rhizosphere, and discusses future studies necessary to understand the role of forest soils in the formation and degradation of these compounds. Results and Discussion Reviewing the present knowledge of the natural formation and degradation processes of chloroacetic acids and volatile organochlorines in forest soil has revealed gaps in knowledge regarding the actual mechanisms behind these processes. In particular, there remains insufficient quantification of reliable budgets and rates of formation and degradation of chloroacetic acids and volatile organochlorines in forest soil (both biotic and abiotic processes) to evaluate the strength of forest ecosystems regarding the emission and uptake of chloroacetic acids and volatile organochlorines, both on a regional scale and on a global scale. Conclusion It is concluded that the overall role of forest soil as a source and/or sink for chloroacetic acids and volatile organochlorines is still unclear; the available laboratory and field data reveal only bits of the puzzle. Detailed knowledge of the natural degradation and formation processes in forest soil is important to evaluate the strength of forest ecosystems for the emission and uptake of chloroacetic acids and volatile organochlorines, both on a regional scale and on a global scale. Recommendation and Perspective As the natural formation and degradation processes of chloroacetic acids and volatile organochlorines in forest soil can be influenced by human activities, evaluation of the extent of this influence will help to identify what future actions are needed to reduce human influences and thus prevent further damage to the environment and to human health caused by these compounds.     

The influence of forest fires on CO, HCN, C2H6, and C2H2 over northern Japan measured by infrared solar spectroscopy

Total column abundances of CO, HCN, C₂H₆, and C₂H₂ have been retrieved from infrared solar spectra observed at Moshiri (44.4°N) and Rikubetsu (43.5°N) in northern Japan from 1997 to 2005. The spectra were recorded with high spectral resolution ground-based Fourier transform infrared (FTIR) spectrometers and total column abundances were calculated by SFIT1 version 1.09e. Deviations of these species relative to their seasonal mean values (ΔCO, ΔHCN, ΔC₂H₆, and ΔC₂H₂) were derived, which showed short-time enhancements in 1998, 2002, and 2003. Good correlations among ΔCO, ΔHCN, ΔC₂H₆, and ΔC₂H₂ in a few months of each year were seen. Since the number of forest fires in Siberia had large enhancements in 1998, 2002, and 2003, trajectory analyses were performed in order to assess the influence of forest fires and it was confirmed that air masses passing over the location of burning points in Siberia reached Moshiri and Rikubetsu. This paper shows that enhancements of these species were driven by biomass burning in Siberia.