辽东山区天然次生林现状与可持续经营探讨

辽东山区的天然次生林占有林地面积的68%,木质和非木质资源丰富,在优化森林结构、保护生物多样性、提升森林功能、提高林地生产力和森林多种效益、增加林农收入、促进区域林业产业发展水平、改善和美化环境等方面发挥着重要作用。文章在阐述辽东山区天然次生林现状与存在问题的基础上,探讨了今后辽东山区天然次生林可持续经营的途径与对策。     

森林经营模式对锐齿栎次生林林分状态的影响

森林经营模式评价是筛选有效经营技术和森林经营决策的基础,为了探讨小陇山林区锐齿栎天然阔叶混交林林分状态对不同森林经营模式的响应,为天然次生林经营提供有益方法,以小陇山林区地带性顶级群落状态特征为参照,从空间利用、树种多样性、建群种竞争势、林分组成4个方面采用遗传绝对距离和相对差异率法量化不同经营模式锐齿栎天然混交林与参照林分的状态差异。结果表明,按结构化森林经营模式进行经营的次生林,其林分状态与参照林分最为接近,其次是天然林采育择伐模式和近自然森林经营模式,平均差异分别为0.141、0.183和0.197。结构化森林经营能使所经营的次生林更加接近自然,尤其在物种多样性和建群种竞争态势方面与地带性顶级群落状态特征差异最小,仅为0.047和0.069。     

兰州南部山区天然次生林近自然化经营技术

兰州南部山区森林是兰州市天然的生态屏障,该地区森林面积大小及森林生态功能的强弱均对兰州市空气质量的改善有着直接影响。在对兰州南部山区森林生长与经营现状调查与研究的基础上,依据德国森林近自然化经营技术,并结合当地立地条件,提出了山杨白桦林和灌木林等天然次生林近自然化经营技术,以期加速天然次生林近自然化经营进程,最终把低质、低效、低产的次生林培育为林分生产力高、生态系统稳定,以及健康、功能多样的近自然森林。     

对天然次生林抚育强度的一点意见

牡丹江林区分布着大面积的天然次生林,以东京城林业局为例,天然次生林的面积占全局有林地总面积的59%,其中柞树次生林占49%,杨桦次生林占10%(1971年)。天然次生林在森林经营中占有重要地位,是重要的后备资源。因此合理组织次生林经营显得非常必要。抚育管理是次生林经营的重要内容,而抚     

辽东天然次生林择伐改造技术

天然次生林构成了辽东山区森林的主体,如何科学合理地将低产、低效、低质的天然次生林培育成高效、优质的林分成为亟须解决的课题。经多年探索,成功总结出适于辽东山区的择伐改造天然次生林的经营措施。文章从适用对象、培育目标、采伐时期选择等方面详述天然次生林择伐改造技术要点。     

论天然林保护工程的科技支撑

何谓天然林，天然林是指依靠自然力形成的森林，包括原始林和天然次生林。原始森林是尚未经人类经营活动或人为破坏的森林，天然次生林是原始林经过采伐或多次破坏后自然恢复起来的森林。［１］天然林保护工程是我国为改善人类生态和社会经济发展的生态环境及物种多样性所...     

AdaptationStrategyofForestryinChinatoGlobalChanges

在综合评价全球气候变化对我国的气候和森林影响的基础上，根据我国的实际，有针对性地从良种选育、人工造林、天然次生林和原始林的经营、间伐和轮伐期的调整、森林多样性保护、森林病虫害防治、森林防火等７个方面探讨了我国适应全球气候变化应采取的林业对策，为我国制定长远的持续发展策略提供参考．     

内蒙古大兴安岭天然次生林经营技术探讨

文章按森林分类经营区划探讨了天然次生林经营技术。     

保护天然次生林改善生态环境

天然次生林是我国重要的森林起源类型之一,它在满足国民经济建设需要、维系自然生态平衡以及保持生物多样性等方面发挥了重要的作用。本文阐述了一个令人担忧的问题——天然次生林面积在减少,质量在下降。由此引发了许多生态环境问题。最后,作者提出了保护天然次生林的几点建议和措施。     

天然次生林立体经营模式的研究

按照生态林业的基本思想和生态学的理论,以辽宁东部山区的天然次生林为对象,建立了森林立体经营模式,并对模式的结构与功能、模式建立后森林生态因子及林分因子的变化、各种经济植物的生长发育状况以及模式内主要经济动植物的人工管理措施等方面进行了调查和分析。结果表明,在天然次生林综合经营的同时,加入各种经济动植物成分,组建多物种、多层次的森林立体经营模式是可行的,它具有显著的经济、生态和社会效益。     

生态学中关键种与物种重要性的概念(英文)

在本文中,对关键种的概念进行了讨论,并介绍了关键种的典型特征及其在群落和生态系统中的判别。在对关键种的研究基础上,首次提出了物种重要性(SI)概念。物种重要性可以简单地理解为生态系统中物种的重要值,它由三个指数构成,即物种结构重要值(SIV)、功能重要值(FIV)和动态重要值(DIV)。本文同时评价了三大硬阔森林生态系统中乔木树种的物种重要性。     

科学引进外来物种正确防治物种入侵

外来物种是当今生物多样性保护的一个重大话题。作者提出了外来物种主要集中在大中城市及周边农村;分析了湖南省外来物种分布现状;提出了正确认识外来物种,科学利用外来物种,建立起立法、检疫、监测等综合防治体系,不断提高防治外来物种入侵的能力和意识,逐步完善防治外来物种入侵的法律制度。     

濒危"表亲"知多少

16馨籍慧黯赫毓癫巍各卜万银翻啊斜一冲攀磷攀彝~}鬓薰兹鲁箭趣瀚熬玺潺谬﹃鸳「…黔毅添赢赢碱鹭夔骥澳彝瓤攫崛i蘸灌黯黔黔颧数巍篡巅鬓誉协、朴箕…镖碱蒸…鲜卿蟀熟姗咧濒橇毅_黯黔衅卿鲜擎暴誓蘸癫森舔囊摹翼翼谬巅瓣雕嘱一(袋鬓)摹攘聆黝沁蒸卿膏卿蒸颤彝锄咖巍洲争钾一拿薪褥岸鬓娜擎i夔鞭鹜壤屑俩一从彝黝毅旨i、黝鬓寿黝嶙一彝鄂豪科黔鸯扬涵奈奢岸毅量爵锄恤暴鄂鼎…、瓣磷,黔聋封娜瓣率喊向彝肇蓦{恻暴勘嘎分蠢霹一画{撇黝鲡磷)濒斌翼户{濒毅量备少俞扛袖鲍黑18濒危“表亲”知多少@郭耕     

Target species identity is more important than neighbor species identity

This study investigates how the ability to overtop other saplings and the ability to capture most of the incident light together determine interspecific competition in young and dense self-thinning stands. To this end we measured crown positions and stratification, and quantified the effect of total foliage mass and foliage mass density of neighboring trees on the relative crown depth (RCD) of target trees. Field measurements were done on naturally established saplings in two large forest gaps of different age (5- and 15-year-old) in The Netherlands, and consisting of four species differing in shade tolerance.     

Bondability of tropical fast-growing tree species I: Indonesian wood species

To estimate the potential bonding performance of bonded wood products from tropical fast-growing tree species, a study on the bondability of Paraserianthes falcataria L. Nielsen, Pinus merkusii Jungh et. De. Vriese, and Acacia mangium Willd from Indonesia was conducted. Two-ply laminations were produced using polyvinyl acetate emulsion (PVAc), urea formaldehyde (UF), resorcinol formaldehyde (RF), and water-based polymer isocyanate (API) adhesives. In order to determine the bonding performance, the block-shear test was applied according to the Japanese Agricultural Standard for structural glued laminated timber under normal conditions and after accelerated-aging treatments. To support this study, the wettability of each wood species was also investigated through contact-angle measurement. The results showed that the bonding performance of low-density P. falcataria was better than that of medium-density P. merkusii and medium-density A. mangium, while the bonding performance of medium-density P. merkusii was better than that of medium-density A. mangium. Furthermore, compared with A. mangium, the small contact angle and good wettability in P. falcataria and P. merkusii result in better adhesion and more intimate contact between the wood surfaces and adhesive.     

Biomass component equations for Latin American species and groups of species

? Studies dealing with the estimation of biomass, site productivity and the contribution of forests to the global carbon balance require the use of allometric equations. There have been a great number of equations developed to estimate biomass components of trees and shrubs in various ecosystems. However, there are less literature compilations that address the calculations of biomass components.

? I report a total of 229 sets of allometric equations to estimate biomass components for 102 species in 72 different forest communities of arid, semi-arid, subtropical, tropical and temperate Latin-American ecosystems.

? The selection of the appropriate allometric model is a key element in the accurate estimation of biomass, stand productivity, carbon stocks and fluxes, and as a consequence, it is important to apply special effort to the selection and estimation of biomass equations.

? I also discuss statistical methods of parameter estimation and recommend the dissection of two conventional allometric equations when biomass studies are conducted on a wide range of diameters. In order to use nondestructive procedures of biomass estimation such as the fractal theory, the null hypothesis that the mean slope b value is equal to 2.67 was rejected for Latin American biomass species.

? This information is critical for the establishment of environmental projects that aim to estimate conventional parameters (i.e., productivity, habitat quality and fuel wood) as well as environmental features (i.e., stocks and fluxes of carbon and nitrogen).

     

关于增加造林物种的多样性引进优良树种的建议

在"天然林保护工程"的启动实施中,增加新的造林树种,丰富林木优良基因也是不可忽视的问题.大兴安岭地区由于气候比较寒冷,无霜期短,可供造林树种比较单一,在一定程度上制约了林业工作的发展,为此,加快林木引种的进程,实现此地区造林树种的多样化,促进林业事业的发展,增加林产品的种类,提高森林的稳定性及抗性,充分发挥森林的防护作用和森林美化、净化价值,更好地为林区经济建设服务具有十分重要的意义.     

One new species and one new record species of Acerophagus(Hymenoptera: Encyrtidae) from China with a key to Chinese species

Two species of Acerophagus from Yunnan Province, China, are reported. One species, A. ovaliclavus sp. nov., is described as new to science, and one species, A.solidus Hayat is reported as new to China. A key to all described species from China based on females is given.All the type materials are deposited in the insect collections of Northeast Forestry University, China.