普氏原羚的分布和种群数量调查

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。     

普氏原羚的历史分布与现状

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。     

独龙江流域羚牛的种群、分布和保护

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。     

羌塘、可可西里无人区野牦牛种群数量和分布现状

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。     

中国中华白海豚的研究和保护现状

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.     

中国疣粒野生稻的分布、濒危现状和保护前景

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。     

三棱栎的分布现状、种群特征、生物学特性及保护对策

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。     

西双版纳野生绿孔雀种群数量及分布现状调查

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...     

长岛海域东亚江豚种群密度和分布的初步研究

长岛海域是黄渤海东亚江豚(Neophocaena asiaeorientalis sunameri)的热点分布区域之一。为了掌握长岛海域东亚江豚的种群密度与分布特征,2019年10月至2021年10月采用截线抽样法进行了5次东亚江豚目视考察。5次考察总航程2 421 km,共发现东亚江豚614次,1 156头次。相同月份调查种群遇见率无显著性差异(P> 0.05),不同月份种群遇见率差异极显著(P <0.01),提示东亚江豚种群在该水域可能存在季节性迁移。按照考察月份对数据进行合并处理,长岛海域5月和10月东亚江豚平均种群密度为(0.56±0.11)头/km²(0.46～0.68头/km²)和(3.63±0.25)头/km²(3.38～3.88头/km²),平均种群数量为(20 209±202)头和(2 971±681)头,这在目前已知所有东亚江豚分布区中是最高的。尽管不同季节种群数量差异显著,但东亚江豚种群在长岛海域的空间分布特征相似,砣矶岛-大钦岛西北侧和东南侧均为高密度分布区,因此...     

SOME RESULTS OF BIRD-BANDING IN THE CONGO (KINSHASA)

The global Blue Swallow Hirundo atrocaerulea was classified as Vulnerable in 2010 on account of its small and rapidly declining population estimated at less than 1 500 pairs. We undertook this study to gain a better understanding of the current status and threats facing this migratory species. Three previously unknown areas that might be part of the species' non-breeding range were identified in Kenya and northern Tanzania. Within its breeding range we identified three previously unknown areas of potentially suitable habitat, one in Tanzania and two in Malawi, which require further exploration. Population viability assessment predicted that the Blue Swallow population will decline by 8% in 10 years. The overall probability of extinction of the species in the wild is 3%. Minimum viable population size analysis suggests that a goal for the long-term conservation of the Blue Swallow should be to mitigate current threats that are driving declines such that the population increases to a minimum of 3 600 individuals. This should consist of at least 900 individuals in each of the four clusters identified, along with a minimum of 500 individuals in at least one of the meta-populations per cluster. The four clusters are located in (1) the southeasten Democratic Republic of the Congo, (2) highlands of southern Tanzania and northern Malawi, (3) eastern highlands of Zimbabwe and (4) South Africa and Swaziland. The current proportions of the Blue Swallow population in strictly protected and unprotected areas on their breeding grounds are 53% and 47%, respectively, whereas on their non-breeding grounds the corresponding percentages are 25% and 75%, respectively. Our reassessment of the Blue Swallow's risk of extinction indicates that it continues to qualify as Vulnerable according to the IUCN/SSC criteria C2a(i).     

Distribution and status of the medicinal leech (Hirudo medicinalis L.) in Turkey

A survey of all the major potential habitats in western Turkey showed that medicinal leeches, Hirudo medicinalis L., are widely distributed over the country and are not rare. They occur in practically all suitable habitats and the only region where they were found to be absent is that of the large river deltas in the south of the country (Çukurova deltas, Göksu delta). There may be zoogeographic reasons for this (Taurus mountains barrier). The application of a semi-quantitative survey method using collecting efficiency (number of leeches collected per hour by a single person) allowed a rapid assessment to be made of its status in a large number of wetlands. Leech density varied considerably from wetland to wetland, and the results enabled a ranking of the Turkish wetlands to be made according to their importance for medicinal leeches. Taking both the leech density and the size of leech habitats into account, the largest populations were identified on the Black Sea coast (Kizilirmak delta, Yeilirmak delta and Karagöl Marshes near Sinop) and in inner and south-west Anatolia (Eber Gölü, Karamik and Sultan Marshes). Commercial exploitation for the pharmaceutical industry and for other purposes takes place at only a few places and does not appear to affect the population seriously. However, many populations are threatened by the draining of their habitats.     

Infraspecific diversity of Cytisus emeriflorus Reichenb. (Leguminosae), an endemic plant with disjunct distribution: Evidence from isozyme data

ABSTRACT

C. emeriflorus is an endemic species occurring in two disjunct areas some 200 km apart: the Pre-Alps of Lombardia and the Pre-Alps of Friuli. Four populations from the western area and five populations from the eastern area were sampled in order to ascertain the amount and the distribution of variation throughout the range of the species. Phenetic measures of isozyme polymorphism were used. Diversity values showed that the species is polymorphic, despite its restricted distribution and the small population size; phenetic distances revealed that partitioning of diversity was largely within rather than among populations. Moreover, little differentiation was found between the two disjunct areas, although the western populations exhibited a slightly higher diversity compared with the eastern ones. The high level of polymorphism and the overall similarity between populations from the two areas may be ascribed to past contacts, and indicate that, despite the present widespread disjunction, the two areas have not evolved independently long enough for divergence to have occurred. There is no evidence that C. emeriflorus is at present genetically depauperated, although its range of distribution must have been much broader in the past; its present reduced distribution area and the small population size may be mainly due to ecological factors.     

滇金丝猴（Rhinopithecusbieti）现状及其保护对策研究

滇金丝猴（Ｒｈｉｎｏｐｉｔｈｅｃｕｓｂｉｅｔｉ）是我国特有的珍稀濒危动物,生活在海拔３８００～４３００ｍ的原始冷杉林中,但有时也会在４３００～４７００ｍ的低矮灌丛、草甸和流石滩上活动达数小时之久,甚至能跨越近千米的无林高海拔地带,因而它们是海拔分布最高的非人灵长类。松萝是它们的主要食物,取食松萝的时间占总取食时间的９１％。猴群活动范围可达近百平方公里。笔者在历时８年的野外考察中,已查明这一物种的全部现存自然种群只有１３个,分布在云南的德钦、兰坪、潍西、丽江和西藏的芒康这五县境内,其现存种群数量为１０００～１５００只;所有现存自然种群几乎均处在相互隔离的状态,群间已不可能进行基因交流,充分表明它们已到达灭绝边缘。然而其栖息地内的商业伐木规模仍在继续扩大,周围的人口压力正在不断增加,各猴群均面临不同程度的偷猎压力。这一现状委实令人担忧。如何拯救这一“国宝”应引起我国保护学家和各级政府有关职能部门的重视     

Doomed to die? Predicting extinction risk in the true hawks Accipitridae

One of the most important tasks in conservation biology is identifying species at risk from extinction and establishing the most likely factors influencing this risk. Here, we consider an ecologically well-defined, monophyletic group of organisms, the true hawks of the family Accipitridae, which are not only among the most studied, but also contain some of the rarest bird species in the world. We investigate which intrinsic and extrinsic factors, covering morphology, life history and ecology, covary with International Union for the Conservation of Nature and Natural Resources threat status, as well as global population size and geographic range size. By decomposing threat status into population size and range size, we test whether any factors are generally important: we found that species with less habitat specialization, a larger clutch size and more plumage polymorphism were associated with lower extinction risk and larger population and range sizes. Species with special habitat requirements might be less capable of dealing with habitat transformation and fragmentation, while species with small clutch sizes might not be able to reverse population declines. Plumage polymorphism might indicate the size of the species' gene pool and could be a good marker of extinction risk. The analyses also emphasized that no single factor is likely to be sufficient when predicting the threat of extinction.     

Biology and life history of Dabry's sturgeon, Acipenser dabryanus, in the Yangtze River

Dabry's sturgeon, Acipenser dabryanus, is a relatively small (130 cm, 16 kg) and now rare sturgeon restricted to the Yangtze River Basin. It behaves as a resident freshwater fish, does not undertake long distance migrations (except for spawning), and lives in a variety of habitats. It historically spawned in the upper Yangtze River, but the spawning sites are unknown. Acipenser dabryanus reaches maturity earlier than do other Chinese sturgeons, which gives the species aquaculture potential, and artificial spawning has been carried out. However, the native population in the Yangtze has sharply declined in the last two decades due to overfishing, pollution and habitat alteration and destruction, especially since the construction of the Gezhouba Dam, which was built in 1981 across the Yangtze River at Yichang, Hubei Province. Since 1981, Dabry's sturgeon rarely occurs below the Gezhouba Dam because downstream movements are blocked. Clearly, conservation of Dabry's sturgeon must be emphasized. Conservation methods may include protecting habitats, controlling capture and stock replenishment.