Resources and bioactive substances from Taiwania (<Emphasis Type="Italic">Taiwania cryptomerioides</Emphasis>)

 Taiwania (Taiwania cryptomerioides Hayata), native to Taiwan, is one of the most economically important tree species grown there. In this article we summarize the current results of phytochemistry and bioactivity of Taiwania extracts, including antifungal, antitermite, antibacterial, and antimite activities as well as cytotoxicity against three tumor cells. The resources of Taiwania are also addressed. Received: January 23, 2002 / Accepted: March 8, 2002 Acknowledgment The authors thank the National Science Council of R.O.C. for financial support (NSC-90-2313-B-002-344). Correspondence to:S.-T. Chang     

切根、截顶对湿地松裸根苗生长调控效果的研究

在江西景德镇和安徽泾县布置了１年生湿地松裸根苗生长后期切和截顶试验，研究其对苗木形态和造林表现的效应及其例题应用制度。两年的结果表明，切根苗的高、径及主根形态指标均低于未切根苗，而侧须根系增加，早切根多次切根处理效应最显著。     

Chemical reactivity of heat-treated wood

Chemical reactivity of heat-treated wood was compared with that of untreated wood. For this purpose, heat-treated pine or beech sawdust was reacted with different carboxylic acid anhydrides in pyridine or with phenyl isocyanate in dimethyl formamide. Compared to controls, weight gains obtained with heat-treated sawdust are smaller showing a lower chemical reactivity. FTIR analyses of lignin and holocellulose fractions, isolated after acidic hydrolysis of polysaccharides or delignification with sodium chlorite, indicate that both components are involved in the reactions. Compared to lignin, holocellulose exhibits important infrared absorptions of about 1,730 cm⁻¹, characteristic of ester or urethane linkages formed. Lower reactivity of heat-treated sawdust is explained by the decrease in free reactive hydroxyl groups in holocellulose due to the thermal degradation of hemicelluloses, considered more reactive than cellulose.     

澳大利亚湿加松F2杂种引种试验结果初报

对种植于广东省蕉岭、四会、信宜、阳东等4个地点的澳大利亚湿加松F2杂种2．5～4．0年生的人工林作了生长量调查和数据分析，结果表明：F2杂种早期生长突出，其年均树高生长介于0．87—1．10m、年均胸径生长介于1．50～1．99cm，比同地点湿地松的树高、胸径分别大19．40％～26．64％，18．78％～47．48％，比马尾松的树高、胸径分别大3．28％～24．71％，42．45％～80．07％。初步认为，湿加松F2杂种在广东省的低山地区有较大的发展潜力。文章还对F2：杂种的变异程度进行了探讨，并提出了F2杂种的利用设想。     

Preliminary studies on the early quality identification ofAuricularia auricular

In production industry ofAuricularia auricular, the varieties quality is most important impact factor on output. For evaluating the early quality of the edible fungus, 9 varieties ofAuricularia auricular (Au9, CF09, CF05, 29, 916, chang10, chang7, Au.Japanese and 8808) were cultured on the medium consists of potato dextrose agar (PDA) and sawdust to test their mycelium growth rate, endurance to high temperature, resistance to mildew, assimilation of nutriment, and resistance to drought. The result showed that the mycelium of Chang 10, CF09, 29 and Au.Japanese varieties had the eminent characteristics such as short lifespan, stronger assimilation of nutriment, and endurance to high temperature and steady growth. These four varieties are determined as superiority varieties ofAuricularia auricular in accordance with the research results. Foundation item: The research was supported by Science Fund of Northeast Forestry University (2004). Biography: Li Ling (1964-), female, Engineer in Northeast Forestry University, Harbin 150040, P. R. China. Responsible editor: Zhu Hong     

Rural livelihood benefits from participation in the taungya agroforestry system in Ondo State of Nigeria

This study examines the strategies and benefits of the taungya farming system to both the government and the rural economy in Nigeria. An interview survey was conducted in which data were collected from 115 randomly selected farmers in five villages in the Oluwa forest reserve, Ondo State, Nigeria. The study examines the extent of participation of rural dwellers in plantation development through taungya farming and the degree of success of this system as an afforestation method. The farmers were predominantly illiterate, within the age bracket of 35–54 years and with small farm holdings. Twenty nine percent relied totally on food from the forest reserve for their livelihood, while 71% also had farm holdings in free areas. Land within the reserve is allocated to farmers free of charge but compensation is paid to landlords on land from free areas. A statistically significant difference was detected in income from the two sources of farmland for the households and but not in the size of land allocated under taungya and free areas. About 184 farmers are involved in taungya annually, and 410 ha of Tectonia grandis has been established for the government of Ondo State.     

红刺玫染色体的观察和核型分析

作者主要对红刺玫细胞染色体计数,并对其核型进行分析。研究结果表明:红刺玫的染色体为三倍体,2n=3x=21;核型公式为2n=3x=21=18m 3sm,属于2A型。     

Dielectric properties of copper-ethanolamine treated Chinese fir (Cunninghamia lanceolata Hook.)

In order to clarify the interaction between copper and wood substances in wood treated with copper containing water-borne wood preservatives, the dielectric constant ε′ and dielectric loss factor ε″ of untreated wood and wood treated with four concentration levels of copper-ethanolamine (Cu-EA) solutions were determined within a temperature range from –100 to 40°C and a frequency range from 100 to 1 MHz. Three dielectric relaxation processes were observed in the ε″ spectrum; among them R-I is based on the reorientation of methylol groups in the amorphous region of wood cell walls and R-II is related to wood extractives. R-III appeared in Cu-EA treated wood, and its magnitude decreases with the concentration of Cu-EA solutions used in this experiment. This relaxation process was considered to be based on the reorientation of copper-ethanolamine-wood complexes in wood cell walls. At low copper retention, the hydrogen in the complex can form hydrogen bonding with adjacent hydroxyl groups, which results in a strong bonding state between copper and wood; at high copper retention, the numerous copper-ethanolamine complexes not only hinder them from forming hydrogen bonding with adjacent wood molecules due to steric hindrance, but also weaken the interaction between wood molecules themselves, which corresponds to reducing ε″ values of both R-I and R-III processes. The results explain the fact of in-creasing copper leaching in wood treated with high concentration copper-based water-borne preservatives.     

核桃楸树皮的没食子酸、鞣花酸及水解单宁成分研究

研究了核桃楸树皮丙酮-水提取物的水溶性萃取部位的化学成分.采用Sephadex LH-20柱色谱及薄层色谱等方法进行分离,经波谱分析及理化性质测定,鉴定了6个化合物:没食子酸(1)、鞣花酸(2)、1,2,6-三没食子酰葡萄糖(3)、1,3,6-三没食子酰葡萄糖(4)、1,2,4,6-四没食子酰葡萄糖(5)及1,2,3,4,6-五没食子酰葡萄糖(6).化合物2、4、6为首次从该植物中分得.     

GPS在林业面积测量中的应用研究

利用两台GPS进行面积测量,将所采集的数据与复枧法罗盘仪闭合导线测量的数据进行对照分析。分析结果认为:在面积3.4hm~2以上时精度可达90％,在面积为8.2hm~2时精度可达95％。