成都市城市森林规划(纲要)

以建设国家森林城市为契机,坚持城乡一体化发展,建立布局合理、绿量充足、生物多样、景观优美、特色鲜明、功能完善的城市森林生态系统,把成都建设成为"创业环境最优、人居环境最佳,综合竞争力最强"的中国中西部特大中心城市和森林生态城市。并将城市森林建设纳入修编的《成都历史文化名城保护规划》和《成都市城市总体规划》。       

Comparison of wood,fibre and vessel properties of drought-tolerant eucalypts in South Africa§

Three drought-tolerant eucalypt genotypes have been investigated for a broad spectrum of properties to provide a basis for comparison on their suitability for various end-uses. The genotypes included were a Eucalyptus grandis × E. camaldulensis hybrid, E. gomphocephala and E. cladocalyx, selected based on previous studies that indicated good potential to tolerate arid conditions, reasonably good volume growth and straightness of stems. In this study, information was added on differences between species and parts of stems in growth (volume and biomass) and properties of wood (density and stiffness), fibres (dimensions and microfibril angle) and vessels (size and numbers). We found high wood densities and stiffness values for E. cladocalyx and E. gomphcephala, making them suitable for construction wood. Logs from the mid-part of the stem had the best timber properties, as the butt logs showed the highest microfibril angle and lowest wood stiffness due to longitudinal juvenility. Such juvenility was also to some degree observed for wood density and fibre length. The information gained will be especially helpful for selecting species and processing options for small farm and community plantations for producing higher-value products that may be sold to generate much-needed income as well as for local uses, such as fuelwood and charcoal.     

Biomass distribution in 40-year-old trees of Japanese black pine

Measurements were carried out to survey the quantity of above- and below-ground biomass and its distribution of five Japanese black pines (Pinus thunbergii Parl.) growing on a sandy soil. The roots, divided into diameter groups, were surveyed using two methods—soil coring and excavation. Average dry weight of total biomass of the trees was 176,185 g. Roots represented 13.2%, below-ground stump 6.5%, stem 70.4% and branches with needles 9.9% of total biomass. Roots made up about two thirds and stump one third of below-ground biomass. Total length of below-ground biomass (except roots with diameter < 0.1 cm) was 479.1 m/tree. Roots with diameter of 0.1–0.2 cm represented only 0.7% of below-ground biomass, however as much as 49.9% of their total length. Roots with diameter over 10.0 cm constituted as much as 21.6% of below-ground biomass, however were only 0.3% of its total length. Root systems had well developed tap roots to maximal depth of 231 cm. The results indicated that mass and length of roots with diameter 0.5–2.0 cm had a close correlation with branch mass. Mass and length of roots with diameter 2.0–10.0 cm closely correlated to stem mass. Stem mass, root mass and root length closely correlated to DBH. A rather low correlation was found between DBH and mass of branches and below-ground stump. DBH was a suitable variable for predicting total biomass.     

建设绿色城市 打造生态合肥

论坛会上有20多位市长参加经验交流,其中贵阳、邯郸、吉林、兰州、大连、合肥、乐山等7市长作了专题报告。贵阳市的经验已经在《中国城市林业》2004(5)期上全文刊登。今年本刊特设"市长论坛"。本期发表了合肥、吉林、大连三市市长文章,其余市长报告将陆续发表。       

沿海防护林体系建设

大连海岸线长达1906km,占辽宁省海岸线总长度的73%,约占全国海岸线总长度的10%。其中陆地海岸线1288km,海岛岸线618km。       

海湾新绿——大连造林绿化掠影

天净沙落,碧海晴空,绿树芳草,雪浪白鸥。今天的大连以其独特的风格和骄人的业绩,荣获了"国家环保城市"、"国家级园林城市"、"亚太地区环境整治模范城市"、"全球生态环境500佳城市"等殊荣,并被联合国授予"人居奖"。       

大树“大搬家”的得与失

大树"搬进城"的做法,上海是走在前面的,目前已有10万棵大树"落户"在上海,多数生长良好,与其说是大树,实际上多数是大树苗(胸径在10-25cm)主要来自浙江萧山、江苏常州、安徽黄山微城三地(均有长期协作关系),树种主要是上海较适应的银杏、香樟和广玉兰,上海对引进大树苗和大树是十分慎重的。首先在制定计划时,就强调要讲科学,对引多少树,引什么树,引多大的树,从何处引树,种到何处大树"大搬家"的得与失去,怎样移怎么种等等都要经过严密的论证和周密的部署。       

果树进城的思考

果树在森林城市绿化中的应用范围越来越广,成为城市森林的重要组成部分,不仅具有良好的绿化作用,还有城市产业和人文特点,本文介绍了果树在沈阳绿化中的应用情况及发展前景。       

构筑林业生态体系 建设和谐绿色佛山

近年来,佛山市坚持以生态建设为中心,加大生态公益林林分改造力度,广泛深入开展全民植树活动,扎实推进城市绿化工作,进一步提高城市森林建设水平。       

太原市城市林业建设思路与实践

太原市是一座具有悠久历史的文明古城,位于山西省中部,晋中盆地北端,东、西、北三面环山。太原属于温带大陆性季风气候,冬季干燥寒冷,夏季炎热湿润,年降水量450mm左右,年均气温9.5℃,最低气温-25.5℃。全市国土面积6988 km2,其中市区面积1460km2,长住人口约280万。建成区人口203万人。