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我国特有珍稀树种珙桐的保护现状及对策 总被引:3,自引:0,他引:3
在分析了我国特有珍稀濒危树种珙桐保护现状的基础上,针对目前珙桐保护工作中存在的问题,提出了保护策略.建议在继续做好就地和异地保护工作的同时,应加强珙桐遗传多样性、生殖生态学及发育生物学研究,惟有如此,才能对珙桐的提出切实可行的保护策略及具体的工作框架和执行方案. 相似文献
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成都平原珙桐驯化繁育及栽培研究 总被引:2,自引:0,他引:2
珙桐为我国特有的单型属树种,被列为我国I级重点保护植物,具有极高的观赏、经济和生态价值。但以珙桐为主的阔叶林群落逐渐衰退,局域种群的稳定性不尽相同。本研究根据"近区采种"的原则,对成都平原珙桐生物学特性、繁育、栽培及驯化等方面进行初步探讨。研究表明,1)嫩枝插条在50 mg·kg-1吲哚丁酸处理下,树龄为5~6年的珙桐生根率分别约为70%;树龄在11年~15年的珙桐生根率却在50%以下。不同激素(IBA、NAA、IAA)对嫩枝生根率比较发现,以IBA和NAA处理生根效果较明显,生根率在65%~97%间。与嫩枝扦插比较,硬枝扦插明显生根率低,其生根率最高的基部萌生条下段也只达5.5%。2)嫁接苗株高比实生苗低,地径比实生苗大;嫁接珙桐愈合好,植株健壮。3)不同时期沙藏方式对种子出苗率影响不明显。不同温度条件下沙藏的珙桐种子出苗率除低温沙藏出苗率较低外,其余处理对出苗率无促进作用。4)高压育苗繁殖成活率高达87.6%,尤其在珙桐林区,短期内可提供早开花的珙桐苗木。同时,对珙桐人工种植管理栽培技术从低海拔引种栽培、播种繁育、扦插繁育和嫁接繁育等方面进行了总结,为珙桐的引种繁育及自然资源保护提供科学借鉴。 相似文献
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C. Grimm H. Schmidli F. Bakker K. Brown P. Campbell M. Candolfi P. Chapman E. G. Harrison M. Mead-Briggs R. Schmuck A. Ufer 《Journal of pest science》2001,74(3):72-84
The existing standardised test systems for assessing the toxicity of crop protection products to the non-target arthropods Typhlodromus pyri (Acari: Phytoseiidae) and Aphidius rhopalosiphi (Hymenoptera: Aphidiidae) are limit tests designed to compare a single-use rate of the product with a water control. The suitability of these test systems for generating dose-response data as required for refined ecotoxicological risk assessment was evaluated. Data on dose-response toxicity of crop protection products to T. pyri and A. rhopalosiphi were generated under worst-case laboratory and to T. pyri under extended laboratory conditions and analysed using the standard Probit method, a logistic regression, a generalised Probit analysis, and the moving average-angle method in order to calculate the LR50-values (application rate killing 50?% of the exposed organisms). The fit of the models, the precision of the resulting LR50 values, and the required minimum number of replicates were compared. In 85?% of the studies, at least one of the statistical methods led to satisfactory results. The moving average-angle method was the most widely applicable method. The results show that the existing guidelines can be used to perform dose-response tests. Implications for risk assessment are discussed. 相似文献
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《Forest Policy and Economics》2000,1(2):177-185
The Ministerial Conference on the Protection of Forests in Europe (MCPFE) has shaped the pan-European dialogue on forests for 10 years now. At three Ministerial Conferences, approximately 40 European ministers responsible for forests agreed on 12 resolutions for the protection and sustainable management of forests in Europe. Building on the achievements of these last 10 years, the MCPFE is moving towards new challenges. This paper presents these achievements of the MCPFE and provides a look into the future, including the relation of the MCPFE to the global forest debate. 相似文献
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兰坪云岭自然保护区滇金丝猴考察 总被引:1,自引:0,他引:1
为查清兰坪云岭自然保护区滇金猴的种群数量及生境状况,兰坪县林业局与大自然保护协会于2004年10月至2005年10月,通过与当地群众座谈、访问等收集相关信息及实地观察等方法初步查清了三个猴群的种群数量、生境情况、活动规律、生存现状。分析了保护区存在的问题,提出了今后的保护措施。 相似文献
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民勤沙区沙丘的基本特征及其移动规律研究 总被引:1,自引:0,他引:1
民勤沙区的沙丘包括新月型沙丘、新月型沙丘链、沙垄、沙堆和复合型沙丘及沙丘链5 种类型;沙丘高度一般为4~10 m;沙丘走向有横向(NE-SW)和纵向(NW-SE)以及多风向形成的不规则形。沙丘移动的基本特征是:(1)风是沙丘移动的动力,风向单一时沙丘移动速度快。(2)沙丘越高移动速度越缓慢。(3)沙丘自西北向东南方向移动为主。(4)沙丘移动的方式有前进式、摆动式和摆动前进式3 种。(5)植被盖度越大移动就越缓慢。(6)一年中5月份移动速度最快,9月份最为缓慢。 相似文献
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建立自然保护区是保护生物多样性的主要方法和手段。我国的自然保护区建设发展得很快,但是仍存在许多困难和问题,当务之急是建立一套完整的自然保护区管理体系、监测体系,组织自然保护区开展资源、生态等方面的监测工作。应用GAP对自然保护区的布局和现状进行分析表明,目前尚未得到有效保护的优先生态系统有27类。并以海南铜鼓岭自然保护区为例,利用RS和GIS技术对自然保护区的生境破碎化进行了监测研究。结果表明研究区生境破碎化程度增加,致使斑块内部物种向外迁移,生物多样性降低。 相似文献
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概述了拱泥机器人主要组成及工作原理。在无障碍运动过程分析的基础上,分析了拱泥机器人避障运动过程的基本规律,建立了避障运动过程的数学模型,可用于避障运动过程计算机仿真研究的仿真模型,也可以作为实际工作中路径规划的重要依据。 相似文献
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《Forest Ecology and Management》2006,221(1-3):13-26
Effective utilization of a patch or cluster approach to growing aspen-white spruce mixtures in the boreal forest requires an understanding of how the faster growing aspen patches influence microclimate and spruce growth in adjacent spruce patches. In this paper we examine, how young (11–13 year old) aspen (Populus tremuloides Michx) patches influence microclimatic conditions in adjacent openings and how these are reflected in the growth of white spruce (Picea glauca [Moench] Voss) on three boreal mixedwood sites in west-central Alberta, Canada. Light levels increased continuously across the aspen stand boundary and reached maximum levels within the opening, while soil moisture was highest near the edge of the opening and then decreased with distance into the aspen stand or into the adjacent opening north of the aspen stand. Light levels were reduced over a greater distance when moving north from aspen stand edges compared to openings located south of the young aspen. These young aspen stands provided growing season frost protection within one tree length from the edge. The growth of white spruce was positively related to initial crown size and either light levels or distance from the edge. Stem volume growth was best predicted by initial tree size and the light levels at the midcrown of seedlings. 相似文献