三棱栎种子特性与其致濒关系初步分析   总被引：3，自引：0，他引：3  

周元 《种子》2004,23(1):13-15

三棱栎是云南特有种,国家二级保护植物,主要分布在澜沧、沧源、孟连、西盟、勐腊等县.研究表明,其萌发温度在20～35℃范围内,萌发率在5.3%～9.1%之间.4个不同分布地和8种温度条件下萌发率差异不显著.本文认为三棱栎濒危的主要原因是:(1)三棱栎果实结实率低;(2)果实的特殊形状,不利于传播;(3)幼苗缺乏竞争力.针对三棱栎的濒危现状和原因,提出了三棱栎的一些保护措施.  相似文献   

珍稀濒危植物柄扁桃的花部特征比较研究     

李俊兰  方海涛  娄菊霞  张鹤 《北方园艺》2009,(1)

通过对2种柄扁桃花(白花和粉花)花部特征比较研究.结果表明:2种类型的花在花冠直径、花瓣长度、柱头高度等方面存在差异,而且白花的单花花粉量,花粉/胚珠比率(P/O)少于粉花.另外,白花的花粉活力和柱头可授性显著高于粉花(P0.05).  相似文献   

珍惜植物桃儿七濒危原因及保护措施研究     

杨丽琴  王俊  任辉丽 《北方园艺》2009,(2)

阐述了桃儿七的生存现状,针对其濒危原因,提出了具体的保护途径,为合理开发利用桃儿七资源提供依据.  相似文献   

Relating tradable credits for biodiversity to sustainability criteria in a dynamic landscape     

Douglas J. Bruggeman  Michael L. Jones  Kim Scribner  Frank Lupi 《Landscape Ecology》2009,24(6):775-790

Tradable biodiversity credit systems provide flexible means to resolve conflicts between development and conservation land-use options for habitats occupied by threatened or endangered species. We describe an approach to incorporate the influence of habitat fragmentation into the conservation value of tradable credits. Habitat fragmentation decreases gene flow, increases rates of genetic drift and inbreeding, and increases probabilities of patch extinction. Importantly, tradable credit systems will change the level of fragmentation over time for small and/or declining populations. We apply landscape equivalency analysis (LEA), a generalizable, landscape-scale accounting system that assigns conservation value to habitat patches based on patch contributions to abundance and genetic variance at landscape scales. By evaluating habitat trades using two models that vary the relationship between dispersal behaviors and landscape patterns, we show that LEA provides a novel method for limiting access to habitat at the landscape-scale, recognizing that the appropriate amount of migration needed to supplement patch recruitment and to offset drift and inbreeding will vary as landscape pattern changes over time. We also found that decisions based on probabilities of persistence alone would ignore changes in migration, genetic drift, and patch extinction that result from habitat trades. The general principle of LEA is that habitat patches traded should make at least equivalent contributions to rates of recruitment and migration estimated at a landscape scale. Traditional approaches for assessing the “take” and “jeopardy” standards under the Endangered Species Act based on changes in abundance and probability of persistence may be inadequate to prevent trades that increase fragmentation.  相似文献   

乳源木莲生长规律的研究   总被引：13，自引：3，他引：13  

王忠平 《福建林业科技》1995,22(2):25-29

本文对人工营造的乳源木莲与杉木等混交的试验林分别不同造林年度、不同立地条件、不同混交比例，设置２１块标准地，采集２３株解析木，调查了大量数据，建立数学模型，初步揭示了９年生乳源木莲树高、胸径、形数、材积、冠幅、根系、侧枝等生长规律。  相似文献   

八种珍稀濒危植物引种试验   总被引：12，自引：0，他引：12  

刘生龙  王理德 《甘肃林业科技》1995,20(3):10-14

１９９２－１９９４年三年来，从内蒙、新疆和甘肃等省（区）的沙区地带引种来的８种珍稀濒危植物，现保存有性和无性繁殖苗近千株，大多已开花结实，经过对沙区８种珍稀濒危植物播种育苗研究认为：准噶尔无叶豆、矮沙冬青、银沙槐３种植物种皮坚硬吸水困难，播前须用浓硫酸处理后再经温水浸泡，才能吸水膨胀发芽；沙生柽柳、半日花、裸果木、绵刺、四合木等植物，种子质地松软，无需特殊处理均可干播发芽，播深适中均能取得较好出苗率。  相似文献   

马尾松与黄山松天然杂种种群特性探讨   总被引：1，自引：0，他引：1  

王宗海  汪德娥  吕聚煜  陈惠民  陈述亮  汪泉 《江西林业科技》2006,(1):29-32

江西庐山、九岭山在黄山松垂直分布下界,发现有马尾松和黄山松的自然杂交种,通称“杉松”。其实,其叶内树脂道边生和中生兼有,且性状稳定和黄山松有质的区别。因此,我们把它拟定为新种,命名庐山松(学名待定)  相似文献   

短柄五加蒸腾作用及其与生理生态因子相关性的初步研究   总被引：12，自引：0，他引：12  

岳春雷  江洪  朱隐湄 《林业科学》2003,29(2):158-161

水分是植物生长和分布的主要限制因子 ,因此对植物蒸腾作用特征及与环境因子关系的探讨一直是植物生理生态学研究的重要内容之一。短柄五加 (Ａｃａｎｔｈｏｐａｎａｘｂｒａｃｈｙｐｕｓ)是分布于我国黄土高原地区的濒危灌木树种 ,具有重要的药用价值。目前 ,已有关于短柄五加无性系种群生长和生殖生物学特征的报道 (田国伟等 ,1 998;王仲礼等 ,1 997;1 998ａ ;1 998ｂ ;1 999;岳春雷等 ,2 0 0 1 ) ,但对其生理生态学的研究尚为空白。本文通过对短柄五加在林下和开阔地两种生境下的蒸腾特征及与环境因子的相关性的比较研究 ,旨在从植物水分…  相似文献   

Tracking the Trade in Ornamental Coral Reef Organisms: The Importance of CITES and its Limitations     

Andrew W. Bruckner 《Aquarium Sciences and Conservation》2001,3(1-3):79-94

The extraction of coral reef organisms for the aquarium and curio trade is reported to be contributing to coral reef degradation. The total international trade and associated impacts are unknown, because data are collected only for organisms listed on Appendix II of CITES, which include stony corals, antipatharians and giant clams. CITES data indicate that trade in live stony coral and reef substrate (live rock) increased by 15–30% each year during the 1990s, with most exports since 1992 from Indonesia and Fiji. Overall, 19% of all stony coral traded (by item) from 1985 to 1997 was live; 71kern-1pt% of this was traded between 1993 and 1997 (52% of total trade). Although tracking trade using information from the CITES Trade Database provides limited information (e.g., coral is reported to genus, and volume is reported by item or weight), the CITES mechanism promotes the development of strategies to protect resources. In response to CITES requirements, Indonesia developed a management plan for sustainable harvest of corals, but not for non-CITES listed species such as soft corals and fishes. Trade in hard and soft coral provides revenue for developing countries; however, in order to be of lasting value the industry must be developed with a conservation ethic. This requires support for international programs such as CITES, management plans for sustainable harvest, and improved enforcement.  相似文献   

Direct somatic embryogenesis in Epipactis veratrifolia,a temperate terrestrial orchid     

Shirin Moradi  Mostafa Arab  Kourosh Vahdati 《The Journal of Horticultural Science and Biotechnology》2017,92(1):88-97

Most temperate terrestrial orchids are endangered species. Attempts to produce plantlets from plants of the genus Epipactis by asexual methods have totally failed. This study was conducted using somatic embryogenesis as a rapid vegetative propagation technique for conservation of E. veratrifolia. For these purposes, effects of different types of plant growth regulators (PGRs), different types of explants, light and dark conditions, and the effect of gibberellic acid (GA₃) and Paclobutrazol (PBZ) were investigated on somatic embryogenesis induction. Abscisic acid (ABA) pre-treatment effectiveness on inducting somatic embryogenesis and increasing the number of embryos per explant were investigated. Subsequently, 16 media were tested to find the best medium for plant regeneration and shoot and root proliferation. BA (3 mg L^?1) resulted in a better response than the other PGRs by supporting the development of 17 embryos per protocorm. PBZ, which resulted in 11 embryos per explant, was better than GA₃. FAST medium supplemented with organic substances was recognized as the best medium for plant regeneration and shoot and root proliferation. ABA pre-treatment had positive effect on somatic embryogenesis initiation. This study, for the first time, succeeded in finding a rapid and suitable protocol for propagation and genetic resource conservation of E. veratrifolia.  相似文献