Results 71 to 80 of about 17,222 (205)

牛山湖两种不同生境小型鱼类的种类组成、多样性和密度 [PDF]

open access: yes, 2007
研究了2003年春季浅水草型湖泊牛山湖小型鱼类空间分布(种类组成、多样性和密度等)与生境异质性之间的关系.根据水生植被状况、离岸距离和水深,选择了两种差异较大且有代表性的生境类型,即近岸沉水植物茂密的生境A和远岸沉水植物稀疏的生境B.使用围网(180m2)在这两种生境中进行小型鱼类的采样,采用多次标志回捕法和Zippin去除法估算了围网内小型鱼类的密度.结果表明,两种不同生境中小型鱼类的种类组成、多样性度量值和密度估算值均存在一定程度的差异:1)生境A中的渔获物由5科14种小型鱼类组成 ...
叶少文, 曹文宣, 李钟杰
core  

Effects of political identity activation and inaccurate metaperceptions on attitudes toward wolves

open access: yesConservation Biology, EarlyView.
Abstract Polarization between groups can undermine durable conservation outcomes. Activating group identities (i.e., an individual's sense of self derived from membership in a group) can exacerbate differences, especially when people hold inaccurate perceptions of their peers and rivals.
Alexander L. Metcalf, Justin W. Angle
wiley   +1 more source

东方白鹳国内圈养种群的统计分析

open access: yes野生动物学报, 2011
应用种群管理软件SPARKS 1.5及PM 2000 v1.214对东方白鹳的国内圈养种群进行统计分析。在有记录的36 a人工圈养的历史中,野外捕获个体在1975~1999年间是构成圈养种群的主要部分,自1984年首个圈养个体出生后,圈养出生个体数量以年平均增长率15.10%速度增长,至2000年取代野外捕获个体数量,成为目前种群发展的主要力量。截至2009年12月31日,我国共有61家动物园或机构圈养了375只东方白鹳个体。种群周期增长率λ=1.0311,性别比例为雄性:雌性=0.927 8 ...
马珺
doaj  

污水处理厂中浮游生物群落DNA指纹及其与水质指标的关系 [PDF]

open access: yes, 2008
以武汉龙王嘴污水处理系统为研究对象,揭示了污水处理各阶段中浮游生物群落的DNA指纹拓扑结构,进而探索了其与浮游生物群落结构和环境理化因子的关系.首先建立了污水处理系统中浮游生物群落总DNA提取方法,然后用原核与真核特异性引物对流程(A2/O氧化沟工艺)中不同阶段的浮游生物群落总DNA进行PCR扩增,用变性梯度凝胶电泳(DGGE)检测,并对平行水样分别进行常规理化因子和浮游生物物种的检测与鉴定.结果显示,各采样点理化因子、物种组成与浮游生物DNA指纹的统计分析结果十分吻合,厌氧、缺氧和好氧阶段间差异较小,
余育和   +4 more
core  

Evaluating the empirical basis for threat attribution in the IUCN Red List

open access: yesConservation Biology, EarlyView.
Abstract Understanding the impacts of different threats on species is key to successful conservation interventions and policies. The International Union for Conservation of Nature (IUCN) assesses threats to species, and the organization's Red List of Threatened Species is a key conservation tool.
Ena Humphries   +5 more
wiley   +1 more source

Community structure and species diversity of Schima superba-Pinus massoniana communities in Dongbaishan Nature Reserve(东白山自然保护区木荷-马尾松群落结构及物种多样性分析)

open access: yesZhejiang Daxue xuebao. Lixue ban, 2015
对东白山(Dongbaishan,DBS)1 hm2森林样地内胸径≥1 cm的木本植物进行统计,初步分析了样地的区系成分、物种组成、群落结构和α多样性.结果表明:样地内共计木本植物48种,隶属23科36属,总计5 493株,以常绿树种为主,共25种,占总优势度的98.18%,重要值的95.22%,总个体数的96.65% ;群落内有明显的优势种、偶见种和部分稀有种,木荷(Schima superba)和马尾松(Pinus massoniana)占显著优势;偶见种和稀有种分别占总物种数的35.42%和20 ...
WANGYunquan(王云泉)   +7 more
doaj   +1 more source

Functional homogenization of terrestrial mammals outside protected areas in the Hengduan Mountains, China

open access: yesConservation Biology, EarlyView.
Abstract Despite the crucial role of human impacts on biodiversity loss, many assessments of this loss focus on single metrics, such as species richness, and overlook the multidimensional effects of human activities. Because of its importance to ecosystem functioning, we investigated the functional diversity of medium‐ and large‐sized mammal ...
Xueyou Li   +8 more
wiley   +1 more source

基于线粒体Cyt b基因和CR序列的养殖貉(Nyctereutes procyonoides)种群遗传多样性和结构分析

open access: yes野生动物学报, 2021
貉(Nyctereutes procyonoides)是一种重要的经济动物。经过50年的人工驯养繁育,国内养殖种群不断扩大,但对其遗传多样性和结构了解很少,难以开展有效的遗传管理。本研究分析了东北、华北地区养殖貉种群(N=160)的线粒体细胞色素b(Cyt b)基因和控制区(CR)序列,并与已经发表的同源序列进行比较。结果定义了5个Cyt b基因和6个CR序列单倍型,其中与俄罗斯产乌苏里亚种共享单倍型分别是3个和4个。种群遗传多样性分析表明,养殖貉种群单倍型多样性处于临界点(Hd=050 ...
魏宏达 李波 魏来 刘志平 姜春明 史迎秋 徐艳春
doaj  

Host location behavior of Aedes albopictus and Empoasca vitis: olfactory and visual effects on their orientation [PDF]

open access: yes, 2015
在昆虫宿主定位行为中,嗅觉与视觉究竟哪个更为重要至今尚无定论。本研究选择福建地区广泛分布、并且具有重大危害的白纹伊蚊(Aedesalbopictus)和假眼小绿叶蝉(Empoascavitis)为研究对象,以干扰害虫对宿主生物的定向通讯行为为研究思路,整合形态学、分子生物学和行为学方法试图揭示嗅觉和视觉在昆虫宿主定位行为中的作用。以期深入理解昆虫的宿主定位行为机制并为害虫防治提供新思路。研究结果如下: (1)应用RACE技术获得白纹伊蚊嗅觉共受体基因(AalbOrco)全长编码序列 ...
章旭日
core  

Automating the analysis of public saliency and attitudes toward biodiversity from digital media

open access: yesConservation Biology, EarlyView.
Abstract Measuring public attitudes toward wildlife provides crucial insights into human relationships with nature and helps monitor progress toward Global Biodiversity Framework targets. Yet, conducting such assessments at a global scale presents challenges.
Noah Giebink   +8 more
wiley   +1 more source

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