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1.
普氏原羚的分布和种群数量调查   总被引:8,自引:1,他引:8  
2003 年8 ~9 月,对青海省境内普氏原羚的分布和种群数量进行了专项调查。调查结果表明,普氏原羚现存7 个种群,累计数量为602 只;其中塔勒旋果种群属首次报道。与以往报道相比,目前元者和鸟岛种群数量呈下降趋势;海晏—刚察种群数量增长明显;湖东—克图种群数量有所回升,但仍没有达到20 世纪80 年代中期时的种群数量。普氏原羚种群数量变化与栖息地质量及人为干扰程度有密切相关。本次调查显示,普氏原羚现存栖息地呈不连续的间断分布,随着区域经济开发力度的加大,其栖息地在不断缩减、生存环境质量仍在继续恶化。  相似文献   

2.
普氏原羚的历史分布与现状   总被引:23,自引:3,他引:23  
蒋志刚  蔡平 《兽类学报》1995,15(4):241-245
普氏原羚是我国特有的珍稀动物,曾分布于内蒙古和青海,现仅生存于青海湖北东北部及西部的鸟岛、察拉滩和小北湖一带,数量不足300只,由于人类稠密地区的阻隔,位于青海湖西的种群与湖东北种群已无可能进行基因交流。由于种群小、易被偷猎、生境破碎和无采食场所等原因。它们已是我国,也很可能是世界上最濒危的有蹄类动物之一,必须立即采取保护措施,否则,普氏原羚有可能在近期内灭绝。  相似文献   

3.
2012年11月至2013年7月间研究了独龙江乡区域羚牛指名亚种Budorcas taxicolor taxicolor(后文简称羚牛)的种群分布、数量和保护现状的问题。研究采用了改良的访问调查和实地调查相结合的方法。其中实地调查独龙江乡羚牛种群一群,调查面积35.70 km2,目测羚牛种群数量58头,适宜生境面积24.46 km2。计算羚牛适宜生境种群密度为2.4头/km2。种群数量和访查信息相符合,说明采用访问调查的方法是可靠的。本研究共计访问调查了独龙江乡的25个村庄,发现共有12个羚牛种群分布在独龙江乡,分布区羚牛适宜生境面积总和为167 km2。综合羚牛分布区面积和访查结果,本研究估算当前独龙江羚牛种群数量为400~450头。根据实地调查中羚牛利用的生境类型,利用GIS分析获得全独龙江羚牛适宜生境面积为1726 km2,可承载超过4000头,因此独龙江区域应为羚牛指名亚种的主要分布区。基于访查结果本研究还分析了羚牛的垂直分布和保护现状,提出降低人为干扰和保护羚牛生境廊道是独龙江羚牛保护的关键。  相似文献   

4.
野牦牛(Bos grunniens)是青藏高原特有的大型有蹄类动物, 主要分布在西藏羌塘, 青海可可西里、三江源, 新疆阿尔金山等地的高海拔生境。我们于2012-2014年在西藏羌塘和青海可可西里对野牦牛进行了较为全面的实地调查, 并且估算西藏羌塘地区野牦牛种群在11,222-21,072头之间, 可可西里野牦牛种群数量在659-1,793头之间。据本次野外调查和历史文献资料显示, 自20世纪90年代起, 中国野牦牛种群数量逐年增长, 但是其分布区面积却逐步缩减, 目前仅分布在几个相对孤立且远离人类居住地的高寒区域。随着全球气候变化与青藏高原人类活动的加强,野牦牛的生存现状依然严峻, 我们仍需加强对青藏高原特有物种的保护。  相似文献   

5.
孟凡信  祝茜  郭建东 《四川动物》2005,24(4):613-616
本文对中国中华白海豚的形态、分类、种群数量及分布、濒危状况及原因和保护现状进行了综述分析,指出中国境内的中华白海豚的保护形势依然严峻,仍需要加强保护措施.  相似文献   

6.
中国疣粒野生稻的分布、濒危现状和保护前景   总被引:8,自引:0,他引:8  
继1978-1982年全国野生稻普查后,又一次对中国疣粒野生稻(Oryza granulata (Nees et Arn.Ex Watt.))主要分布点的居群特征、濒危现状和破坏情况进行了野外生态学研究。由于行政区划的改变,目前疣粒野生稻在中国分布的市(县)达30个。它在群落盖度为90%-210%下生长良好,具有抗旱和适应中度干扰的能力。聚集参数分析表明在群落中居群以集群分布为主。该物种主要通过重力和动物传播种子,居群间的基因流有限,形成了典型的集合种群(metapoulation)结构。生境丧失对疣粒野生稻的生长造成非常严重的后果,巳有12.9%的疣粒野生稻居群灭绝,83.9%的居群处于中度和重度的干扰之下。由于各地区的破坏程度不平衡,目前疣粒野生稻的分布被压缩到海南省的西南部山区和云南省和澜沧江中下游、南汀河流域,面临热区开发的巨大威胁。研究中建立了中国疣粒野生稻的总DNA库,作为易位保护的手段之一和开展保护遗传学研究的基础;并讨论了居群遗传结构与居群分布格局之间的相互关系和保护中需注意的问题。  相似文献   

7.
绿孔雀(Pavomuticus)在世界共3个亚种,其中P.muticusimperator主要分布于我国云南、缅甸东部、泰国和印度等地[1~3]。三十多年前,在西双版纳的大部分地区均有该种的分布,是有名的“孔雀之乡”[4]。随着人类经济活动的影响,云...  相似文献   

8.
三棱栎的分布现状、种群特征、生物学特性及保护对策   总被引:6,自引:2,他引:6  
孙卫邦  周元  赵金超  陈革 《生态学报》2004,24(2):352-358
三棱栎是现存壳斗科植物的原始类群 ,是受国家 2级重点保护的珍稀树木。调查表明 ,三棱栎在云南孟连、澜沧、西盟、沧源及泰国北部清莱 (Chiang Rai)等地仍有小面积分布 ,在云南呈现单株散生、萌生林、单优次生种林和共优种林 4种群落类型。单株散生、萌生林和单优次生林是当地人群不合理利用山地资源和对植被破坏的结果 ;共优种林属原始植被 ,但未见大面积单优势种群落 ,常小斑块状镶嵌于亚热带常绿阔叶林中。在被严重破坏后进行封山管理的植被中发现一株高 16 m的三棱栎孤立木 ,其周围 90 0 m2内有 16 8株三棱栎小树和幼苗 ,并开始形成小种群。三棱栎结实量大 ,而有胚种子比例仅 9%~ 11% ,种子萌发不困难 ,有胚种子的发芽率达 70 %以上。迁地保育试验显示 ,三棱栎在昆明可露地栽培后表现出速生性。目前 ,分布区土著民族仍在不同程度地对三棱栎进行砍伐利用 ,加上紫茎泽兰等外来植物对种群的入侵 ,使其面临严重威胁。建议在自然保护区外建立三棱栎保护点 ,扩大异地繁育栽培面积 ,进行种质资源的有效保护和资源的持续利用。  相似文献   

9.
广东省原鸡种群数量、分布及栖息地现状的初步调查   总被引:3,自引:1,他引:2  
广东原鸡栖息地分布在徐闻,雷州,信宜,高州,阳春5个县(市),为孤立的三块,呈岛屿状分布,总面积2501.62km^2,总体数量680-750只,原鸡数量最多,面积最大的一块栖息地是由信宜,高州,阳春3块小栖息地组合而成,成为广东原鸡的主要栖息和分布地。  相似文献   

10.
中国灰鹤的分布与数量现状   总被引:4,自引:0,他引:4  
王有辉  王虹 《四川动物》2003,22(1):35-38
分析文献结合笔者的研究得知,除广东、广西、福建、海南、香港、澳门和台湾外,中国其余省区均有灰鹤分布,但目前分布的区域正在缩小;采用模糊数学思维对灰鹤进行种群数量测算,在20世纪与21世纪之交,我国灰鹤数量可能超出21632-22401只。  相似文献   

11.
动物集群的群体行为决策是营集群生活的动物调节其群体活动、而获得集群生活收益的重要手段。受动物自身行为和需求的影响,动物集群的群体决策有不同的外在表现形式和过程。本研究以青海湖湖东地区的普氏原羚种群为对象,于2010 年3 月至2012 年3 月对普氏原羚集群的群体决策过程进行了观察和记录,并对所得数据采用非参数检验方法进行统计与分析,分析结果表明:1. 普氏原羚集群的群体决策类型为不完全民主型,需要有一定比例的个体共同参与群体决策过程才能达成群体决策,而参与群体决策的个体比例随群体规模的增加而降低;2.参与决策的个体因性别不同而有不同的表现,且在决策过程所需时间上存在差异,这可能是导致普氏原羚产生同性聚群现象的原因之一。这是在野外直接对大型有蹄类动物集群的群体决策过程进行的为数不多的研究,还需要更多的野外研究来探究不同类型动物群体决策过程及其与同性聚群产生机理之间的关系。  相似文献   

12.
Giraffe populations have suffered a 40% decline in the past thirty years, making them a new priority for conservation and there are considerable uncertainty and disagreement over the taxonomic classification of giraffes. Consequently, there has never been a more critical time to fully understand the global population size and distribution of all giraffe subspecies. The Rothschild's giraffe Giraffa camelopardalis rothschildi (Linnaeus, 1758) is arguably one of the most imperilled giraffe subspecies. Once widespread across southern Sudan, Uganda and Kenya, the Rothschild's giraffe is now confined to a few, isolated and enclosed populations throughout Kenya and Uganda, with only one natural population remaining. Information about Rothschild's giraffe population size, distribution, and conservation history is patchy, and confined to recondite or inaccessible resources. Here, I present a review of taxonomy, distribution, conservation status and population size of the Rothschild's giraffe and present the most recent estimate of population sizes based on direct census data. Although the Latin name affixed to Rothschild's giraffe is subject to discussion, continued reference to this subspecies as G. c. rothschildi is strongly recommended.  相似文献   

13.
  • 1 The stripe‐backed weasel Mustela strigidorsa is one of the rarest and least‐known mustelids in the world. Its phylogenetic relationships with other Mustela species remain controversial, though several unique morphological features distinguish it from congeners.
  • 2 It probably lives mainly in evergreen forests in hills and mountains, but has also been recorded from plains forest, dense scrub, secondary forest, grassland and farmland. Known sites range in altitude from 90 m to 2500 m. Data are insufficient to distinguish between habitat and altitudes which support populations, and those where only dispersing animals may occur.
  • 3 It has been confirmed from many localities in north‐east India, north and central Myanmar, south China, north Thailand, north and central Laos, and north and central Vietnam. Given the limited survey effort, the number of recent records shows that the species is not as rare as hitherto believed. Neither specific nor urgent conservation needs are apparent.
  相似文献   

14.
在查阅相关文献及标本的基础上,对杜鹃属(Rhododendron L.)种类都支杜鹃(R.shanii Fang)的地理分布和种群现状进行了全面调查分析,并对该种的濒危级别进行了评价.结果表明:都支杜鹃为大别山狭域分布种,分布范围仅限于安徽省岳西县、霍山县与湖北省英山县三县交界处面积110 km2的狭长区域内,主要生于海拔1400m以上的山脊或靠近山脊的山坡上.目前仅存11个自然种群,种群占有面积总和1.2 km2;其中含有成年个体的种群有10个,成年个体总数仅存约5 400株;种群中幼体和亚成体数量远少于成年个体且大多分布于种群的边缘地带.各种群的面积和规模差别悬殊;最大种群占有面积40 hm2,最小种群占有面积2 hm2;成年个体数量上千的种群有2个,个体数量不超过100株的种群有3个.该种的地理分布呈不连续分布,生境片断化明显.根据调查结果及IUCN濒危物种红色名录分级标准,可确定都支杜鹃濒危级别至少应为易危级(vulnerable,VU).  相似文献   

15.
16.
As ancient gymnosperm and woody plants, cycads have survived through dramatic tectonic activities, climate fluctuation, and environmental variations making them of great significance in studying the origin and evolution of flora biodiversity. However, they are among the most threatened plant groups in the world. The principal aim of this review is to outline the distribution, diversity, and conservation status of Cycas in China and provide suggestions for conservation practices. In this review, we describe the taxonomy, distribution, and conservation status of Cycas in China. By comparing Chinese Cycas species with its relatives worldwide, we then discuss the current genetic diversity, genetic differentiation of Cycas, and try to disentangle the potential effects of Quaternary climate changes and topographical events on Cycas. We review conservation practices from both researchers and practitioners for these rare and endangered species. High genetic diversity at the species level and strong genetic differentiation within Cycas have been observed. Most Cycas species in southwest China have experienced population retreats in contrast to the coastal Cycas's expansion during the Quaternary glaciation. Additionally, human activities and habitat fragmentation have pushed these endangered taxa to the brink of extinction. Although numerous efforts have been made to mitigate threats to Cycas survival, implementation and compliance monitoring in protection zones are currently inadequate. We outline six proposals to strengthen conservation measures for Cycas in China and anticipate that these measures will provide guidelines for further research on population genetics as well as conservation biology of not only cycads but also other endangered species worldwide.  相似文献   

17.
18.
Indigenous palm species of Peru are listed with data on their distribution patterns, ecology, frequency, density in the ecosystems, and conservation status. Peruvian palm flora includes 140 native species in 34 genera with the following distribution patterns: strictly Andean (17), Andean and Subandean (3), strictly Subandean (19), Subandean and Amazonian (20), strictly Amazonian (78), Amazonian and South peripheral (2), South peripheral (1). About 43% of the species occur at very low or low frequency in the country and about 9% are insufficiently known in situ for their conservation status to be defined. There are no Extinct species. Sixteen of the 17 strictly Andean palms are threatened species; 3 of them are Endangered, while only 5 strictly Subandean, 3 Subandean-Amazonian, and 4 strictly Amazonian palms are in these categories.  相似文献   

19.
The Cape Gannet Morus capensis is one of several seabird species endemic to the Benguela upwelling ecosystem (BUS) but whose population has recently decreased, leading to an unfavourable IUCN Red List assessment. Application of ‘JARA’ (‘Just Another Red-List Assessment,’ a Bayesian state-space tool used for IUCN Red List assessments) to updated information on the areas occupied by Cape Gannets and the nest densities of breeding birds at their six colonies, suggested that the species should be classified as Vulnerable. However, the rate of decrease of Cape Gannets in their most-recent generation exceeded that of the previous generation, primarily as a result of large decreases at Bird Island, Lambert’s Bay, and Malgas Island, off South Africa’s west coast (the western part of their range). Since the 1960s, there has been an ongoing redistribution of the species from northwest to southeast around southern Africa, and ~70% of the population now occurs on the south coast of South Africa, at Bird Island in Algoa Bay, on the eastern border of the BUS. Recruitment rather than adult survival may be limiting the present population; however, information on the seabird’s demographic parameters and mortality in fisheries is lacking for colonies in the northern part of the BUS. Presently, major threats to Cape Gannet include: substantially decreased availability of their preferred prey in the west; heavy mortalities of eggs, chicks and fledglings at and around colonies, inflicted by Cape Fur Seals Arctocephalus pusillus and other seabirds; substantial disturbance at colonies caused by Cape Fur Seals attacking adult gannets ashore; oiling; and disease.  相似文献   

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