阻隔法防治草履蚧研究

通过对草履蚧[Drosicha corpulenta (kuwana)]进行胶环，毒环，绑扎塑料裙和毒绳等阻隔试验，结果表明，应用废机油加羊羊脂（5:1)进行涂环阻隔防治，效果最好，其粘性持续时间达到80－120d，利用“阻隔法”防治草履介的防治最佳时期应设在草履蚧卵开始孵化至上树前的1月上旬－2月上旬。     

中国鹅掌楸混合芽的发生和形态建成

本文继中国鹅掌楸花芽分化细胞形态学观察的研究之后,我们又系统观察了混合芽从发生至花器官建成的形态变化、芽的类型和分布以及芽端生长点的细胞形态学,试图为鹅掌楸属的系统学研究、植物性分化的生理学研究和种子品质的遗传学研究提供基础资料和理论依据。     

24%氨氯吡啶酸水剂防治林地阔叶杂草试验

选用24％氨氯吡啶酸水利，对林地一年生及多年生阔叶杂草、灌木进行防除试验。结果表明，试验剂量在1200～3600g ai／hm^2范围内时，对杂草的防效可达90％以上，对灌木防效达70％以上。该药剂对针叶用材林幼林慎用。     

Public health effects of accidents in self-employed forestry work

Little is known about the extent of work-related accidents occurring during the performance of forestry work by the non-industrial private forest owner or their assistant (hereafter called self-employed NIPF). The absence of an effective accident registration system largely excludes this group from accurate representation in official statistics. In this study, data from 1996 to 2001 were collected from hospital injury records managed by the Umeå Accident Analysis Group at the University Hospital in Umeå. During that period, it was found that 485 persons in the Umeå region were given medical attention due to injuries possibly acquired during self-employed forestry work. Questionnaires about the accidents were sent to each of the 485 injured persons and 80% were returned. Responses revealed that 225 of the respondents were injured during self-employed forestry work. Out of these, 81% performed fewer than 31 days of forestry work annually. Due to the injury, 29% had been on sick leave for some period of time and 42% had persistent symptoms. On average, each injury led to 13 days of sick leave and 24 hours of institutional care. Firewood production was shown to be a key factor behind the large number of accidents for self-employed NIPF. Further studies on the lack of knowledge about how the work should be done and conscious risk taking should be considered as an important link to the development of effective accident prevention strategies.     

Tracking leaf area index and coefficient of light extinction over the harvesting cycle of black wattle

The amount of photosynthetic radiation intercepted by a crop is a function of the incident solar radiation on the plants, the leaf area index (L _AI), and the light extinction coefficient (k). We quantified L _AI and k in stands of black wattle (Acacia mearnsii De Wild.) over a 7-year growth cycle at two locations in the state of Rio Grande do Sul, Brazil. Our study was conducted in commercial stands in agroecological regions with high densities of black wattle plantations. L _AI was calculated as the ratio between the leaf area of a tree and its planting space, and k was derived from Beer’s law. L _AI depends on the planting site and stand age. Between the two sites, the L _AI was similar over time, the amount of variation differed. Values of k depended only on stand age, with the highest average observed for stands up to 5 years old. The trend of k during the plantation cycle was inversely proportional to L _AI and was correlated with L _AI, leaf area, leaf dry mass, canopy volume, height, branches dry mass, total dry mass, and crown diameter.     

Improvement of the tissue culture technique for <Emphasis Type="Italic">Melaleuca alternifolia</Emphasis>

Tea tree oil is extracted from the leaves and twigs of Melaleuca alternifolia (Maiden & Betche) Cheel, and it is widely used in medicines, food preservatives, cosmetics and health care products. Traditional propagation of M. alternifolia from seeds does not necessarily transfer the desired characteristics from their mother trees, the seedlings are not uniform, and the multiplication rate from cuttings is relatively low. For these reasons, it is necessary to develop tissue culture techniques for this species. This study showed that an efficient explant initiation medium for M. alternifolia was MS 1/2 + BA 0.6 mg L^?1 + NAA 0.1 mg L^?1 + sucrose 30 g L^?1, which yielded a 75.9 % initiation rate. An efficient multiplication medium was MS + BA 0.3 mg L^?1 + NAA 0.15 mg L^?1 + sucrose 30 g L^?1, which yielded a 4.3 multiplication rate and 3.2 cm shoot length. The rooting medium was MS 1/2 + IBA 0.1–0.25 mg L^?1 + sucrose 15 g L^?1, which yielded a 100 % rooting rate, 2.94–3.32 roots per individual and 1.36–1.44 cm root length. Local red-core soil was suitable as a transplant medium, and yielded 98 % survival. This study improved the tissue culture technique for mass-propagation of M. alternifolia, enabling the production of high quality plants for market.     

Temporal and spatial dynamics of an old-growth beech forest in western Japan

Dendrochronological approaches enable us to understand forest stand dynamics by estimation of disturbance history and age structure. The present study was conducted in an old-growth beech forest in a forest reserve in western Japan. Increment cores were taken for tree ring analysis from all canopy trees in a 50 m × 130 m study plot. Radial growth release criteria were developed to identify significant growth releases in each tree ring series and to characterize the disturbance history of the study site. The age structure of the forest was indicative of continuous establishment by Fagus crenata and simultaneous establishment by Magnolia obovata. A variety of low-intensity disturbances were identified in each decade, especially after the 1900s, but the occurrence of high-intensity catastrophic disturbance was rare, and likely played an important role in maintaining species diversity in the existing forest canopy. The results also suggest that F. crenata regenerates gradually before and after both large- and small-scale disturbances, whereas M. obovata and Betula grossa regenerate only after large-scale catastrophic disturbances.     

The performance of community organisers in promotion of community forestry in Leyte Province,Philippines

A study was conducted to assess the role and effectiveness of community organisers in supporting the development of people’s organisations in achieving community-based forest management objectives in Leyte Province Philippines. Community organisers were found to be effective in forming people’s organisations (POs), motivating people to participate in voluntary activities organised by POs and encouraging cohesiveness among PO members. Community organisers manage to raise the level of environmental awareness and knowledge of members of people’s organisations, develop leadership interest and skills, create various livelihood opportunities and provide direction and facilitate the establishment of large tree plantations. However, the short duration of community organisers’ contracts (typically two years) is insufficient to establish mature and cohesive POs prepared to assume management on their own, including the management of tree plantations. Further, lack of training and funding support, low wages, delayed payment of salaries and limited time to work with people’s organisations, as well as the pressure to produce tangible outputs such the establishment of large tree plantations, prevents them from placing greater emphasis on the development and empowerment of the people.     

Forest resources and environment in China

Covering a vast territory, China is rich in forest resources and diversified environments. The changes in forest resources have a direct bearing on environmental quality. This paper gives a detailed account of the dynamic change in forest resources in China, including the overall process of forest evolution, the status quo, and features of the existing forest resources and the development and use of major forest resources. In addition, it analyses the current situation of China’s environment and explores the main contributing factors based on the overall environmental situation. To achieve sustainable management of forest resources and improve the environment in China, the Chinese Government attaches great importance to the protection and development of forest resources as well as to environmental development and improvement. The paper gives an overview of current thinking for sustainable forest resource and environmental development in the future and highlights the current focus of efforts toward this objective.