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对中国特有珍稀濒危植物乐东拟单性木兰(Parakmeria lotungensis)的分布现状、资源量、种群结构和群落特征进行了全面的野外调查。结果表明,乐东拟单性木兰零星分布在我国18°44′~29°24′N,107°50′~119°09′E之间的热带至亚热带森林中,估测个体数量不足15000株,其中成年植株数量不足2500株。生境破碎化与乐东拟单性木兰自身的生物学和生态学特性是影响种群更新的重要因素。人为破坏是造成乐东拟单性木兰种群急剧缩减的直接原因,对乐东拟单性木兰的分布现状提出了保护策略和建议。 相似文献
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以分布样地类型作为一维资源位,应用Levins、Hurlbert生态位宽度公式和Pianka生态位重叠以及生态位相似比例公式对单性木兰乔木层14个群落优势种群的生态位特征分析。结果表明:(1)单性木兰具有最大位宽度,对环境资源的利用具有明显优势,是群落中的建群种;(2)生态位宽的种群可能产生较小的生态位重叠,生态位较窄的种群间也会产生较大的生态位重叠,这主要取决于物种的生物学特性和对环境资源的需求;(3)单性木兰分布地的坡向、基岩裸露度、坡度等因子是影响单性木兰分布的重要因子。 相似文献
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香港珍稀濒危植物的分布及保育 总被引:3,自引:0,他引:3
在第一批共388种中国重点保护的珍稀濒危植物中,有14种分布于香港特别行政区。其中蕨类植物2种,裸子植物2种,被子植物10种。此14种珍稀濒危植物,除了狭叶瓶尔小草外,亦分布于广东省。而其中被列为国家级渐危种类的土沉香及白桂木,在香港则较为常见。本文阐述了此14种珍稀濒危植物在香港的分布情况及其保育工作。 相似文献
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濒危植物长蕊木兰的核型 总被引:1,自引:0,他引:1
报道了长蕊木兰(Alcimandra cathcartii)的染色体核型,核型公式为2n=2x=38=22m+15sm(3sat)+1st。核型类型属于Stebbins的2A型。第18条染色体为st染色体,第5、6、7条sm染色体的短臂上各具有1个随体。间期核为简单染色中心型(simple chromocenter type),有丝分裂前期染色体为中间型(interstitial type)。对前人关于木兰属和含笑属植物的核型研究结果进行了比较分析,长蕊木兰与含笑属亲缘关系较近,但稍有区别,而与木兰属的亲缘关系较远。 相似文献
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井冈山地区珍稀濒危植物及其生存状况 总被引:1,自引:0,他引:1
开展国家珍稀濒危保护植物的考察、研究,对探讨区域生物多样性的性质、评价生态环境的状况和质量,提出适当的自然保护、管理对策等,均具有重要的指导意义.本文调查研究了井冈山地区珍稀濒危植物的种类、数量、分布、生长状况以及重要木本植物的群落特征,探讨了珍稀濒危植物的系统学与生物地理学特征.结果表明,井冈山地区有濒危苔藓植物2种,各类珍稀濒危野生维管植物199种.其中被《世界自然保护联盟濒危物种红色名录》收录50种,被《中国物种红色名录》收录160种,被《国家重点保护野生植物名录(第一批)》收录49种,被《濒危野生动植物种国际贸易公约附录》收录90种.本区珍稀濒危植物的种类和数量大体上与峨眉山相当,而远高于武夷山和太白山,在系统学与生物地理学上有重要意义,具有极高的保护价值.本区保存有较大面积的以珍稀濒危植物为优势种的群落,如资源冷杉(Abies beshanzuensis vat.ziyuanensis)、华榛(Corylus chinensis)、白豆杉(Pseudotaxus chienii)、南方红豆杉(Taxus wallichiana var.mairei)、福建柏(Fokienia hodginsii)、穗花杉(Amentotaxus argotaenia)、闽楠(Phoebe bournei)、马醉木Pieris japonica)、井冈山杜鹃(Rhododendron jinggangshanicum)等群落. 相似文献
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野外定位观测了单性木兰的花期物候、访花昆虫种类、访花频率、访花行为和同花期植物种类,并对其花粉散播距离和繁育系统进行了检测,旨在探讨制约单性木兰传粉过程的某些因素,为单性木兰的保护生物学提供科学依据。结果表明,单性木兰雄株和雌株在花期物候上存在差异,雌株在结实上存在明显的大小年现象。单性木兰以虫媒传粉为主,雄株访花昆虫30种,雌株访花昆虫仅14种,雌株和雄株共有的访花昆虫仅6种。单性木兰同花期植物共17种,其访花昆虫种类大部分与单性木兰的访花昆虫种类相同。蜂类和蝶类均非单性木兰的传粉者,其结实率低的原因不仅与访花昆虫种类少和访花频率少有关,更与其缺乏有效的传粉昆虫有关。 相似文献
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采用水蒸汽蒸馏法提取单性木兰种皮的挥发组分,用GC-MS分别定性定量分析了提取的油层精油和溶解在水中的化学成分。结果表明,挥发组分的提取率为4.2%,其中,油层精油得率为3.5%,主要成分中萜烯类化合物多,含量高,其中罗勒烯37.3%、D-苧烯9.03%、对-伞花烯8.10%、β-月桂烯7.79%、β-反-罗勒烯4.08%、对-孟-1-烯4.00%、α-侧柏烯3.11%;水层乙醚萃取率0.7%,其中α-松油醇6.13%、对-伞花烃5.57%、D-苧烯5.33%、6-甲基-3,5-庚二烯-2-酮4.44%、4-甲基-4-戊烯-2-酮4.16%。 相似文献
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There are five wild populations of Cycas fairylakea in Guangdong Province,China,three of which are newly found.A study of the biological characteristics of C.fairylakea populations showed that this species had a narrow colonization area within 300 hm2,and an island pattern of distribution.Because of the overexploitation,urbanization,environment pollution,plant diseases,and insect pests,the wild populations and individuals of C.fairylakea decreased markedly in the past decades.All five populations have an opposite pyramid age structure,few coning plants,few seed production,and low level of seed germination rate or sterility.In conclusion,C.fairylakea in Guangdong Province was threatened seriously and an urgent need to take effective efforts to protect the plants and habitats in its location sites was required. 相似文献
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在介绍八角莲属的用途和我国八角莲的野生资源概况的基础上,从生物学特性、繁殖特性、生境状况和人为因素等几方面分析了导致八角莲处于濒危状态的原因。并提出了就地保护、迁地保护、种质资源收集和资源发展结合利用的三项有效保护性措施。 相似文献
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峨眉山区属于亚热带季风气候区,野生药用植物资源十分丰富。经过三年的野外调查和文献资料整理,首次建立了峨眉山以蕴藏系数、保护缓急程度等7项指标在内的定量评价濒危药用植物指标体系。结果表明:峨眉山目前1655种野生药用植物(含变种、变型)中,受到生存威胁的药用植物种类共56科102属152种。其中急需保护的有19科29属41种,分别占其科属种数的33.93%、28.43%和26.97%,代表种类主要有峨眉金线兰、峨眉黄连、峨眉拟单性木兰、峨眉岩白菜等;需要保护的有22科,29属,35种,分别占其科属种的39.29%、28.43%和23.02%,代表种类主要有四川木莲、峨眉荚蒾、峨眉忍冬、峨眉雪胆等;一般保护的有41科59属76种,分别占其科属种的73.21%、57.84%和50%,代表种类主要有黄连、川桂、八角莲、威灵仙等。 相似文献
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长白山区属温带气候,野生药用植物资源十分丰富。经过6年的野外调查和查阅文献资料,首次建立了以蕴藏系数、保护缓急程度等7项指标在内的定量评价珍稀濒危药用植物指标体系。结果表明:长白山区目前1 004种(含变种、变型)野生药用植物中,受到生存威胁的药用植物种类共有59科、98属、124种。其中急需保护的有22科、30属、31种,分别占受威胁药用植物的科、属、种数的37.29%,30.61%,25%,代表种类主要有草苁蓉、人参、天麻、刺参、黄檗、平贝母等;需要保护的有29科、43属、53种,分别占受威胁药用植物的科、属、种数的49.15%,43.88%,42.74%,代表种类主要有高山红景天、木通马兜铃、刺五加、党参、辽细辛、北五味子等;一般保护的有34科、38属、40种,分别占受威胁药用植物的科、属、种数的57.63%,38.78%,32.26%,代表种类主要有穿龙薯蓣、祁州漏芦、黄花乌头、羊乳、手参、大叶小檗等。 相似文献
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4种野生牡丹种子休眠和萌发特性及与其致濒的关系(英文) 总被引:1,自引:0,他引:1
与栽培牡丹相比,野生矮牡丹、四川牡丹和紫斑牡丹的种子一般较小,但野生黄牡丹种子则明显大于栽培牡丹。这4 种濒危的野生牡丹种子的休眠与萌发特性与栽培牡丹的有明显差异:萌发生根期需半年以上,但通过胚培养可使之减至2 周;萌发温度以10~15℃为宜, 超过20℃则明显不利于生根及上胚轴生长; 打破上胚轴休眠需要严格的低温;野生牡丹种子的萌发率及打破上胚轴休眠后的出苗率也大大低于栽培牡丹,而且在不同分布地之间存在较大差异。实验证明:在自然状态下野生牡丹缺乏充分的传粉,特别是居群间的传粉不足,导致其种子质量低下;而野生牡丹种子特殊的萌发特性,特别是严格的上胚轴休眠,则是导致其出苗率极低及自然状态下幼苗和种群稀少的重要内因。生化测定结果表明:在低温打破牡丹种子上胚轴休眠过程中,子叶中的萌发促进剂GA3 含量明显升高,抑制剂ABA 含量显著下降;而胚乳中的各种激素含量则变化不大,胚轴中的激素变化无明显规律,因此认为子叶是控制牡丹种子上胚轴休眠的关键部位。 相似文献
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Patrick Williot Eric Rochard Gérard Castelnaud Thierry Rouault Rémy Brun Mario Lepage Pierre Elie 《Environmental Biology of Fishes》1997,48(1-4):359-370
The European Atlantic Sturgeon, Acipenser sturio, has received increased attention in France because of population declines due to overfishing and deterioration of spawning grounds. Conservation of this species requires many actions, including publicizing the necessity to protect this fish and its habitats, investigations on catches and probable spawning grounds, and on artificial reproduction, which is still in an experimental stage. During its sea life, European Atlantic sturgeon occur from the Bay of Biscay to the Bristol Channel and North Sea. Presently, the number of young fish in the Gironde Estuary during summertime is low and the population has a unimodal age structure. At the time this paper was written, the last recorded reproduction of sturgeon in the Gironde system occurred in 1988 (new evidence of reproduction was discovered in 1995). Growth of young fish from the 1988 cohort was faster than that previously determined for others cohorts. Over our study period (1980–1994), the availability of wild broodfish declined. Successful artificial reproduction of wild-caught females requires an optimal physiological state; any delay decreases their reproductive potential. Acclimatization of wild-caught juveniles to fresh water was most successful when fish were transported and held upon arrival in low salinity water. For such wild-caught juveniles, the first food intake usually occurs several months after capture, but remains irregular. These findings will be used to improve ongoing efforts to restore A. sturio. 相似文献
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Seed germination of Melocactus sergipensis N.P. Taylor & M.V. Meiado,the newest Brazilian cactus destined for extinction
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Marcos V. Meiado 《Plant Species Biology》2016,31(4):296-299
Recently, a new cactus was discovered in an area of the Caatinga, a tropical dry forest of north‐eastern Brazil. Although this discovery is excellent news, Melocactus sergipensis is critically endangered because it is affected by deforestation of native vegetation and chemicals used in the maize crop, next to the holotype locality. The aim of this study was to evaluate the seed germination and seedling survival of the newest Brazilian cactus. All germination treatments were performed at room temperature and white light or continuous darkness. For the evaluation of establishment, 50 seedlings were examined at 30‐day intervals for 5 months. I did not observe seed germination of M. sergipensis in continuous darkness, which shows that the newly discovered species is positive photoblastic. However, a high germinability was observed under white light (80.0 ± 10.8%), indicating that the seeds of the newly discovered species are able to germinate and the light is needed for seed germination. After 5 months, seedling mortality was less than 5%. These results show that the seedlings of the newly discovered cactus can be produced in a glasshouse, providing support for studies on ex situ conservation of a species that could become extinct in the near future. 相似文献
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野生动植物贸易活动的特点及影响因子研究 总被引:3,自引:1,他引:3
不受控制的贸易可能导致野生动植物面临生存危机。探讨野生动植物贸易活动的特点和影响因子有利于提高野生动植物贸易的管理水平。本文从生物因素、社会因素、经济因素和文化因素等角度综合分析了除木材与海洋渔业以外的野生动植物贸易活动的特点。与一般贸易相比,这些野生动植物贸易活动具有传统性、地域性、流动的方向性、季节性、分散性、替代效应、反馈效应和补充性等特征。影响某一野生动植物物种进入野生动植物贸易活动的生物因子包括种群大小、易获得性、个体大小、周期性波动、耐受性、替代性等;社会因子包括政策、执法力度、社会心理、收入水平、猎捕技术等;同时,文化传统也会影响人们利用野生动植物和进行相关贸易的方式与范围。对野生动植物贸易活动特点和影响因子的分析为管理相关野生动植物贸易活动提供了依据。 相似文献
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Cheri Gratto‐Trevor Susan M. Haig Mark P. Miller Thomas D. Mullins Sidney Maddock Erin Roche Predensa Moore 《Journal of Field Ornithology》2016,87(1):29-41
Most of the known wintering areas of Piping Plovers (Charadrius melodus) are along the Atlantic and Gulf coasts of the United States and into Mexico, and in the Caribbean. However, 1066 threatened/endangered Piping Plovers were recently found wintering in The Bahamas, an area not previously known to be important for the species. Although representing about 27% of the birds counted during the 2011 International Piping Plover Winter Census, the location of their breeding site(s) was unknown. Thus, our objectives were to determine the location(s) of their breeding site(s) using molecular markers and by tracking banded individuals, identify spring and fall staging sites, and examine site fidelity and survival. We captured and color‐banded 57 birds in January and February 2010 in The Bahamas. Blood samples were also collected for genetic evaluation of the likely subspecies wintering in The Bahamas. Band re‐sightings and DNA analysis revealed that at least 95% of the Piping Plovers wintering in The Bahamas originated on the Atlantic coast of the United States and Canada. Re‐sightings of birds banded in The Bahamas spanned the breeding distribution of the species along the Atlantic coast from Newfoundland to North Carolina. Site fidelity to breeding and wintering sites was high (88–100%). Spring and fall staging sites were located along the Atlantic coast of the United States, with marked birds concentrating in the Carolinas. Our estimate of true survival for the marked birds was 0.71 (95% CI: 0.61–0.80). Our results indicate that more than one third of the Piping Plover population that breeds along the Atlantic coast winters in The Bahamas. By determining the importance of The Bahamas to the Atlantic subspecies of Piping Plovers, future conservation efforts for these populations can be better focused on where they are most needed. 相似文献