珍稀濒危植物蛛网萼的种子形态及萌发特性

研究蛛网萼种子萌发的生物学特性,以了解该种在自然条件下更新困难的原因和使其致濒的机制。在对其种子种皮解剖结构分析的基础上,开展不同赤霉素质量浓度、不同浸泡温度以及贮藏时间对蛛网萼种子萌发影响的研究。模拟试验结果表明赤霉素对种子萌发有促进作用,较高浓度赤霉素(1 000 mg/L)处理下萌发最早且发芽率最高;浸泡水温为25℃,发芽情况最好;随着冷藏时间延长,种子萌发率越低。综合来看,种子萌发特性导致蛛网萼在自然条件下更新困难的原因可能是:蛛网萼种子小虽然能够占有更多的安全位,但在竞争中处于劣势;种子在合适的条件下萌发速度慢,发芽率低,萌发不整齐;种子萌发对温度和水分的要求高,适应范围狭窄;种皮对种子萌发的阻碍。这些因素可能是导致该物种濒危的重要原因。     

飞机草地理分布、危害、传播和防治技术的研究进展

飞机草是一种入侵性杂草,在我国已大面积发生并且仍未得到有效控制。文章对飞机草的地理分布及其对畜牧业、农产品、人畜方面的危害进行阐述,分析其传播途径,并从农业、物理、化学、生物防治技术方面进行探讨并研究其进展,为飞机草的综合防治提供参考资料。     

Using ecological niche modelling to identify diversity hotspots for the herpetofauna of Pacific lowlands and adjacent interior valleys of Mexico

This article documents the conservation status of the herpetofauna in the Pacific lowlands and adjacent Balsas Basin and Chiapas Depression regions and the presents the results of modelling species spatial distributional patterns through GARP analysis, to identify hotspots of species richness, endemic and geographically restricted species in the study area. It also compares the distribution of these hotspots with the distribution of protected areas and intact seasonally tropical dry tropical forests, the dominant vegetation type in the study area and experiencing high deforestation rates. A total of 301 reptiles and amphibian species occur in the study area accounting for a third of the Mexican herpetofauna, and recording high levels of endemism and endangerment. Hotspots of species richness and endemism were located in coastal Jalisco, a considerable portion of the Colima state, as well as scattered areas in Michoacán, Guerrero, and Oaxaca. These areas should receive highest priority for protection. Unfortunately, there was a minimum correspondence when comparing the distribution of actually and proposed protected areas with hotspots identified. Fortunately, areas of high species richness, endemism and restricted species coincided with those where intact seasonally tropical dry tropical forests still exists. These areas should receive high priority in future plans for seasonally tropical dry tropical forests protected areas. It is hoped that this paper will call attention to the need for establishing a network of protected areas in the study area, as has been proposed by previous studies.     

河南省野生葡萄属植物资源保护评价

为科学评价河南省野生葡萄属植物资源,根据资源调查数据结合资料报道,以"濒危系数"和"优先保护值"为指标,制定了河南省野生葡萄属植物资源优先护存等级定量评价指标体系,并进行了优先保护排序,为野生葡萄属植物的保护、开发利用提供了理论依据。     

安徽鹞落坪森林群落优先保护评价体系

在对鹞落坪国家级自然保护区的植物物种、群落进行调查的基础上,进行保护评价和多样性分析。结果表明：共记录物种145科786种;通过濒危评价,得出鹞落坪植物极危种有6种,濒危种15种,易危种41种,近危种66种,安全种658种;通过物种优先保护级别划分,一级保护2种,二级保护11种,三级保护21种,四级保护752种;通过对鹞落坪国家级自然保护区的17种典型森林群落进行累计确限度排序,得出青冈栎Cyclobalanopsis glauca群落、江南桤木Alnus trabeculosa群落有最高的优先保护值,而檫木Sassafras tzumu群落、黄山栎Quercus stewardii群落有最低的优先保护值。     

会计信息与会计信息失真

概述会计信息的定义、特征及作用；阐述会计信息失真的涵义、类型、特点、手段及具体表现；指出其对经济秩序乃至整个社会的危害；并针对目前我国经济管理活动中会计信息失真的现状、探索防范与治理策略。     

濒危植物景东翅子树种群的分布、年龄结构及其动态特征

调查研究了景东翅子树种群的分布、年龄结构及其动态特征,并讨论了濒危的原因.野外调查的4个种群中,3个分布于季风常绿阔叶林,1个分布于次生灌丛.在4个种群中共调查到景东翅子树99株(含幼树).结果表明,景东翅子树属于衰退型种群,其中缺乏幼树和胸径≥20 cm的大树.景东翅子树种群的存活曲线为DeevryⅢ型,生活史中存在...     

福寿螺发生为害习性观察及防治技术研究

通过对福寿螺发生为害的调查和生活习性的观察,初步掌握其为害情况、发生世代、繁殖速度和生态习性,并提出了螺害的防治策略和措施,为控制螺害的扩散蔓延提供科学依据。     

浙江省特有野生珍贵植物濒危原因及保护对策

根据5 a的实地调查和综合前人研究成果,浙江省特有野生珍贵植物共有14科16属17种。对资源种类、分布、濒危原因和价值等进行了分析,提出了该类植物资源的保护对策。     

洛阳地区干热风对小麦危害的分析及防御

对洛阳市干热风出现时间、发生频率以及对小麦危害进行了分析,提出了防御干热风的具体措施。