米东区森林病虫害防治工作存在的问题及对策

森林病虫害防治是国家减灾工程的重要组成部分,对保护森林资源,改善生态环境,促进国民经济和社会可持续发展具有十分重要的意义。     

我国桉树木材性质及其变异规律研究进展

概述了国内桉树木材解剖性质、物理力学性质、化学性质及其变异规律的研究现状,对桉树木材性质变异的影响因子及其材性遗传相关性研究进行了总结,最后分析其存在的问题,并展望了桉树材性遗传改良的研究前景。     

Linearity and non-linearity in mechano-sorptive creep of softwood in compression and bending

Summary Non-linearity of softwood in axial mechano-sorptive creep during moisture cycling can be characterised as departure from linear behaviour. Linear behaviour is shown by experimental measurement to be a gradual approach to a creep limit with exponentially decreasing increments of compliance, J_i, per moisture cycle, when tested under a constant stress. On the other hand, when the stress is progressively increased by a small increment after each moisture cycle, the compliance increments will progressively increase, having a value of , where n is the cycle number. By subtracting one compliance increment from the succeeding one, the value of J_i can be obtained. Analysis of experimental results in bending tension and compression showed that the compression test pieces departed from linearity at total strains around 0.14% to 0.15%, the bending test pieces showed slight evidence of non-linearity at about the same strain, whilst the tensile pieces were approximately linear up to 0.18% strain.This project was supported by the U.K. Science and Engineering Research Council and by the European Commission     

内蒙古湿地资源保护恢复中的问题及对策

文章简要地分析了围垦湖沼、上游截流、过度利用及工艺技术落后等人为因素对湿地资源的破坏情况与负面影响,给人们赖以生存的湿地生态环境带来严重的不可逆转的后果,并有针对性地提出了几点建议。     

德国小城镇绿化特色及其启示

以德国南部小城镇加米施-帕滕基兴(Garmisch-Partenkirchen)市为例,在介绍该市园林绿化概况的基础上,重点介绍其民居庭院绿化与阳台绿化的特色;并对如何更好地发展中国小城镇绿化进行了探讨。       

Differences in composition of endophytic mycobiota in twigs and leaves of healthy and declining Quercus species in Italy

The composition of the endophytic fungal assemblages in Quercus cerris, Q. pubescens and Q. robur, three oak species most susceptible to decline, was investigated in Fagarè (Padova), Ulignano (Pisa), and Radda in Chianti (Firenze). The endophytic assemblages were studied as a function of health status of the whole tree and of twigs and leaves. The effect of station altitude was tested on Q. cerris. Samples were gathered from healthy and declining trees. In April (bud opening time) 20 twigs and 10 leaves were collected from each tree. Fungi were isolated from twig segments and leaf portions. A total of 23 fungal genera with 27 different species were isolated, in addition to a few sterile mycelia. Eleven species were found to be common to all three oak species, while other species were found only on one oak species, suggesting host specificity. Among the fungal species isolated, some were known to be pathogenic (Apiognomonia quercina, Colpoma quercinum, Diplodia mutila, Phomopsis quercina). The colonization frequency (CF) of pathogenic species varied between 0.9% for A. quercina in Q. cerris and 60.2% for P. quercina in Q. robur. Analysis of variance showed a statistically significant difference among the oak species tested. The CF was higher in declining trees in comparison with healthy trees, and also in twigs vs. leaves. The CF was found to be higher for Q. cerris trees growing at sea level as compared with those situated at an elevation of 350–400 m. In stands where, on account of particular ecological conditions, pathogenic behaviour is displayed simultaneously by more than one endophytic fungal species, trees accentuate their decline.     

广东薇甘菊发生现状、防治和研究进展

文章概述了广东省薇甘菊发生现状,分析薇甘菊防控应采取的策略,综述防控工作机制、防控措施以及生物防治方面的研究进展,并进行分析探讨。     

广西田阳敢壮山两栖爬行动物资源调查及保护

2004至2005年对田阳敢壮山地区的两栖爬行动物资源进行了调查,结果表明:该地共有两栖爬行动物27种,其中两栖动物11种,隶属于5属4科1目,爬行动物16种,隶属于10属8科2目.区系特点为:物种组成较丰富;华中-华南区种类丰富;区系组成较简单,以东洋型和南中国型为主;特有种所占比例较低.提出在开发旅游资源的同时,加强对该地两栖爬行动物物种多样性及其生境的保护,合理利用两栖爬行动物资源,同时加强对乌龟、中华鳖、眼镜蛇等的人工驯化等保护对策.     

园林植物病虫害发生特点与防治进展

本文从园林植物病虫害防治的重要性入手,分析了园林植物病虫害的特点,指出了园林植物病虫害防治的发展方向,为今后开展园林植物病虫害防治工作提供了有益的借鉴。     

澳大利亚辐射松遗传育种及其借鉴

澳大利亚辐射松遗传改良在过去的几十年中取得了较大的成绩, 其育种计划与育种策略在一定程度上反应了当前世界林木育种水平。较详细地介绍与分析了澳大利亚辐射松遗传改良的历程与成就, 供我国林木育种工作者参考。     

内蒙古大兴安岭森林分类区划存在的问题及建议

森林分类区划是为了解决天然林的修养生息和恢复发展而提出的,但禁伐区、限伐区、商品林经营区划分在实施过程中存在一些问题。文章主要针对其存在的问题,提出一些可行性的建议和对策。     

我国山苍子开发利用的现状与发展对策

为给我国山苍子产业的发展提供决策依据,详细介绍了山苍子的习性、栽培现状、主要用途,就我国山苍子开发利用中存在的一些问题进行分析,并从加强品种选优、开展集约化经营技术研究、加强山苍子资源的统一管理和利用等方面提出了发展对策。     

广西大明山/龙山保护区生物多样性保护管理的SWORT分析及对策

在考察广西大明山保护区现状基础上,运用SWORT方法,分析广西大明山保护区生物多样性保护管理的优势(Strength)、劣势(Weakness)、机会(Opportunity)和威胁(Threat),并提出了相应的对策与建议。     

沙棘林的水土保持功能及其在治理和开发黄土高原中的作用

研究结果表明，5－7年生沙棘林冠层可截留降水8.55-49.0%，并降低雨滴动能，枯枝落叶层重5.46t/hm^2，其最大持水量可达15.31t/hm^2，有1cm厚枯枝落叶层覆盖地表，即可基本控制水土流失；根系可以提高土壤的抗冲性和抗蚀性，与无根系土壤相比，可减少土壤冲刷量55％－88％。据1988－1994年雨季径流小区测定，沙棘林在栽植后4－5年可充分发挥水土保持作用，与农地相比，可减少地表径流量87.1%，减少土壤流失量99.0%。此外，它还可提供大量薪材，提高土壤中有机质的氮素含量，生产沙棘果实，具有重要的开发价值。     

常绿和落叶阔叶树叶中N和P的变化及转移

从叶完全展开到生长季结束对常绿阔叶树种铁冬青、红楠和海桐及落叶阔叶树种日本朴、银杏和木叶的N和P浓度进行了定期测定。结果表明,常绿阔叶树种新叶的N和P浓度从5—7月急剧下降,然后小幅波动,而老叶的N和P浓度变化缓慢。落叶阔叶树种的N和P浓度随着季节的推移而明显下降。大多数树种的P转移率大于N转移率。常绿阔叶树种的N和P的转移率大于落叶阔叶树种。     

Growth and ecophysiology of seedlings of Podocarpus falcatus in plantations of exotic species and in a natural montane forest in Ethiopia

The potential role of exotic tree plantations in facilitating successional processes on degraded areas was evaluated in southern Ethiopia by comparing seedling characteristics, transpiration and photo-synthetic performance of Podocarpus falcatus seedlings in Eucalyptus plantation, Pinus plantation, adjacent natural forest and clear-felled plantation site. P. falcatus seedlings exhibited differences in architecture between Eucalyptus and Pinus plantations. They had higher leaf area, shorter internode length and greater number of lateral branches in Eucalyptus plantation. At similar vapor pressure deficit (VPD), P. falcatus transpired much less than E. saligna, especially at higher VPDs. Analysis of fluorescence parameters in the leaves showed no significant differences in the level of dark-adapted and light-adapted fluorescence yield (Fv /Fm and ΔF/Fm, respectively), electron transport rate (ETR) and nonphotochemical quenching (NPQ) among seedlings grown inside plantations and adjacent natural forest, indicating similar photosynthetic performance. Nevertheless, there was evidence of photoinhibition in P. falcatus in the clear-felled site which had low fluorescence yield but high values of NPQ as protection from photoamage. The light response curves of ETR, NPQ and ΔF/F m , showed similar light saturation behavior among the seedlings grown inside plantations and natural forest and suggested a sequence of light-adapted to shade-adapted behavior in Natural forest > Eucalyptus plantation > Pinus plantation. The results show the structural flexibility, better water-use and adaptability of P. falcatus in its use of the understory environment of plantation species.     

Purposes and challenges of public participation in regional and local forestry in Finland

Public participation in regional and local forest planning in Finland was researched. The questions were: (1) What is the purpose of public participation? (2) What are the challenges of public participation? The results are based on the analysis of discourse communities in a case study concerning a Regional Forest Programme and forest management planning. It was shown that the purpose of participation was to promote communication at the regional level and to gather information at the local level. The general conclusion is, that the regional forest programmes include practices to offer possibilities for communication among participants. This does not mean, that all the programme processes have reached consensus automatically. The case studied here reached compromise. The case study points out problems faced, if public participation would become common practice at the local level on non-industrial private forests lands. In forest management planning it would result in an excessively demanding mediator/expert role for the planner. The need to consider all relevant issues, e.g. biodiversity management, would also become apparent. The study supports the idea that public participation as communication has better possibilities to promote sustainable forest management than public participation as information gathering.     

我国沙棘开发利用事业与《沙棘》杂志--纪念《沙棘》杂志创刊15周年

198 8年世界上第一种反映国内外沙棘资源开发利用的学术性与技术性相结合的科技期刊———《沙棘》杂志创刊。 1 5年来 ,在有关部门、单位和全体沙棘工作者的大力支持和编辑部的努力下 ,《沙棘》杂志与我国的沙棘资源开发利用共同发展 ,从最初的每年赠阅几千册 ,发展到目前订阅发行过万册。发行地区遍及我国各省 (区、市 )和国际上沙棘分布区各国。它全面深刻地宣传了沙棘开发利用的效益和途径 ,推广了沙棘资源开发利用技术 ,办出了成绩 ,办出了特色 ,有力地促进了沙棘开发利用事业的发展 ,为我国生态建设、西部开发做出了突出贡献。该杂志…     

我国中小企业安全管理工作中存在的问题及对策研究

指出了中小企业的迅速发展取得了非常大的经济效益和社会效益，但安全管理工作中仍然存在很多问题。分析了我国中小企业在安全管理工作中存在的问题，探讨了造成这种状况的原因，并在此基础上提出了解决这些问题的对策和建议。