Life history traits and mechanisms of endangerment inRanalisma rostratum

Ranalisma rostratum (Alismataceae) is an endangered aquatic plant, and now there is only one population existing in China. In its natural habitat, Huli marsh in Chaling, Hunan province, the best growing plants have been observed at microsites where the water depth is 5∼10cm, and the plants grow in emergent form.R. rostratum reproduces asexually or sexually. The recruitment of asexual propagules into population is a very important way to maintain the natural population size. Although seed production does not appear to limitR. rostratum, restricted dispersal of propagules and seeds, low seed viability, low germinability, slow growth of seedlings under all conditions, and habitat loss due to agriculture appear to be more important reasons for the endangerment of this plant. Supported by the national Natural Science Foundation of China Wang Jianbo: born in 1964, Ph. D, Associate professor     

Quantitative Assessment on Endangerment Degree of Rare Animal and Plant Species in Tibet, China

It is of profound theoretical and practical significance to study endangerment status of rare species in Tibet. Index system is firstly set down for quantitative assessment of rare animal and plant species, then endangerment degree of wildlife under special state protection are calculated, which is expressed by value E. The results reveal that Yunnan snub-nosed monkey （Rhinopithecus bieti）, Himalayan tahr （Hemitragus jemlahicus） and Gigantic Cypress （Cupressus gigantea） have the highest E respectively in animals and plants. According to value E, all species are categorized into 4 ranks： critically endangered（0.6-0.8）, endangered （0.4- 0.6）, vulnerable （0.2-0.4） and lower risk （ E ≤ 0.2）. By comparison of the first five animals and plants of the highest E, each sub-ecozone bears a distinct identity.     

报废汽车上路的危害及应对措施

随着汽车使用量的增多,报废汽车的数量也越来越多,由于各种原因,每年有近40%的报废汽车流向非法渠道,这些车辆的使用大大增加了交通安全隐患。本文从报废汽车管理现状出发,分析了报废汽车上路的危害,并从各方面提出应对措施。     

珍爱生命拒绝毒品

介绍了常见毒品的主要种类和危害以及戒毒的痛苦 ,并对目前常用的戒毒方法作了简介 .     

浅析沙尘暴的危害及防治对策

初步分析了沙尘暴的特征、危害、形成原因及发展趋势，并提出了相应的防治对策。     

华南淡水鱼类保护对策研究

在调查分析华南淡水鱼类致危原因的基础上，针对濒危现状提出保护水域自然环境、合理捕捞、坚持合理引种、建立自然保护区、开展濒危鱼类生物学研究等5项保护措施。     

喀斯特环境地质灾害

本文论述了喀斯特地质环境引起的干旱、岩漠化、洪涝、渗漏、突水等地质灾害的形成机理和危害。     

大鸨的濒危机制及保护对策

基于大鸨(Otis tarda)的一系列野外研究数据,从内因和外因两个方面探讨了大鸨的濒危机制,并提出相应保护对策.大鸨的濒危内因主要体现为繁殖力低下、变通性差和行为表现上的神经质;外因主要体现在人为干扰和破坏上,人为无节制的活动导致大鸨繁殖成功率下降、生境片断化和生境质量退化.因此提出保护对策如下:严格控制并约束草原上的人为活动,尽可能保证大鸨栖息生境的优质化和完整化;加强人工繁殖及野化实验,壮大野生种群.     

胶东海岸野生玫瑰(Rosa rugosa)的濒危现状与保护策略

玫瑰是具有重要种质和生态价值的濒危植物,胶东海岸是玫瑰在我国的主要分布区之一．通过野外调查和种群特征分析,基本查清了该区域内现存的玫瑰野生分布区(点)及主要分布区的生境特征、玫瑰种群的数量、空间格局,揭示了人为导致的生境破坏、玫瑰种子传播受阻是导致野生玫瑰种群数量持续减少、有性繁殖成功率低的主要原因．在此基础上,提出应对该区域的野生玫瑰种群采取就地保护、迁地保护和利用性保护相结合的多途径保护策略．