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1.
主要从湖北沙湖湿地自然保护区白尾鹞(Circus cyaneus)的生境偏爱和影响因子两方面分析中国东南部越冬区白尾鹞的种群动态。方差分析表明:年度间白尾鹞丰富度差异不显著。T检验表明:4a季节间白尾鹞丰富度差异极显著,秋季高于冬季。方差分析表明:4种生境中白尾鹞的丰富度存在极显著差异,草甸芦苇农田水域。4种生境中白尾鹞丰富度变异系数为:草甸水域芦苇农田。草甸生境是白尾鹞相对较好的越冬生境。多独立样本非参数检验(Kruskal-Wallis H法)表明:4种生境中雀形目鸟类和环颈雉的丰富度均存在极显著差异。多元线性回归模型(Enter进入法)显示:白尾鹞丰富度与其捕食对象丰富度在芦苇和草甸生境中呈强正相关,在农田和水域生境中相关性不显著。虚拟线性回归模型(Enter进入法)表明:草甸中的影响因子极显著的影响草甸中白尾鹞的丰富度。方差分析表明:草甸中白尾鹞的丰富度随草甸面积的下降而显著性下降。T检验表明:围网对白尾鹞在水域生境出现频次无显著影响。  相似文献   

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白头鹞(Circus aeruginosus)和白腹鹞(C. spilonotus)的分类地位在过去曾存有争议,而分类上的变化有可能误导相关的记录。本文就白头鹞和白腹鹞的分类沿革进行了简要梳理,指出白腹鹞幼鸟及日本型与白头鹞的形态较为相近,并对白头鹞在国内的已知记录作了详细考证。结果发现,国内关于这两种鹞的历史记录确实因分类变化、辨识错误或文献解读而存在混淆。经仔细核查文献,辅以检视标本,认为白头鹞于新疆、北京、云南、贵州、青海、内蒙古和四川的记录存在有说服力的确实证据,其余地区的已知记录则应谨慎对待。  相似文献   

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为了查明高寒草甸退化对表栖节肢动物的群落结构及多样性的影响,于2014年5月、7月和9月利用陷阱法对若尔盖县境内的沼泽草甸、草原草甸、中度退化草甸和重度退化草甸4种生境的表栖节肢动物群落进行了调查,共获得表栖节肢动物8364只,隶属于4纲17目123类(科或属)。优势类群为长跳属(Entomobrya)和球圆跳属(Sphaeridia),其中长跳属仅出现在草原草甸。重度退化草甸表栖节肢动物各多样性指数均显著低于其他生境,表明高寒草甸退化对表栖节肢动物群落组成有明显影响。此外,沼泽草甸表栖节肢动物9月的个体数量和丰富度指数高于5月和7月,其他生境均以7月较高,5月和9月较低;中度退化草甸和重度退化草甸的Shannon指数在不同月份间差异显著,Simpson指数仅在重度退化草甸有显著月份差异。不同生境间的月份差异表明,高寒草甸退化还可以影响表栖节肢动物的季节动态。回归分析表明,植物及土壤环境因子对表栖节肢动物群落的个体数量和多样性有显著影响。研究结果表明,高寒草甸退化可以通过改变植物群落及土壤环境等因子影响表栖节肢动物群落组成和多样性。  相似文献   

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陕西渭河平原地区鸟类物种多样性研究   总被引:4,自引:0,他引:4  
胡伟  陆健健 《生物多样性》2001,9(4):345-351
1999年12月~2000年10月,按冬、春、夏、秋四季,在渭河谷地咸阳地区3个阶地上取有代表性的区域作样带调查,记录鸟类种类和数量,分析不同生境鸟类多样性及其变化规律。本次调查共记录到鸟类124种,隶属于15目35科79属。研究表明,该地区的鸟类总体α多样性水平较高,达3.2845,但不同季节各阶地的多样性水平不高;较高的β多样性指数反映了鸟类种类和组成在不同阶地间变化较大。阶地间多样性的差异表明我国渭河平原地区湿地对鸟类多样性有显著的影响,水是限制鸟类分布和栖息的重要因子。  相似文献   

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2015—2016年4个季节,采用样线法和样点法结合调查鸟类并基于遥感信息分析生境结构,研究了大山包自然保护区9个1 km~2样点鸟类多样性及其与生境的关系。结果表明:大山包共有鸟类16目41科127种,包含国家重点保护鸟类14种;雀形目、雁形目、鸻形目鸟类为主,共27科80种,数量最多的是斑头雁(Anser indicus)、小云雀(Alauda gulgula)、黑颈鹤(Grus nigricollis),共占总数量的50.09%;种类以留鸟(占49.61%)和鸣禽(51.97%)为主,数量以冬候鸟(58.13%)和水鸟(60.28%)为主;40.94%的种类和60.28%的数量均偏好水域湿地生境类型;Pearson相关系数表明,水域面积占比与冬季和春季鸟类数量显著相关(P0.05),森林-灌丛面积占比与夏季和秋季鸟类种类显著相关(P0.05);大山包是重要的鸟类栖息地和越冬地,其生境结构对鸟类种类和数量有巨大影响;营建水域、森林-灌丛、沼泽湿地等多种生境类型及其空间组合,是保护大山包鸟类多样性的重要途径。  相似文献   

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森林-草原交错带夏季鸟类群落多样性特征   总被引:4,自引:0,他引:4  
2004~2006年夏季利用样线法研究了内蒙古高原东南缘森林-草原交错带鸟类群落多样性特征及变化规律.共记录鸟类73种,隶属于13目28科56属,鸟类区系具有明显的古北界特征.鸟类群落物种数和密度年间差异不显著,α多样性随森林-草原交错带环境梯度变化而发生显著变化:在不同植被地带之间,物种数、密度、Shannon-Wiener指数和Pielou指数差异极显著、但科-属多样性差异不显著,鸟类群落α多样性各项指数表现为森林带<交错带森林草甸区>交错带草甸草原区>草原带的特征与变化趋势(DG-F为交错带草甸草原区>森林带);其中,森林草甸区是鸟类物种多样性的显著增长区,具有最高的物种数和密度,明显体现了交错区的边缘效应,草甸草原区是鸟类向草原过渡的显著变化区域、物种多样性开始显著减少.β多样性随不同植被地带逐级发生显著变化,环境差异最大的森林带-森林草甸区和草甸草原区-草原带具有最高的β多样性,物种替代速率最大;鸟类物种替代速率与环境梯度"陡度"有密切关系.鸟类优势种在各植被地带之间存在较大变化.鸟类群落的物种数、密度和物种多样性(H')与森林斑块数呈显著的正相关性,在大尺度空间上森林斑块数是影响鸟类群落多样性的最主要因素.  相似文献   

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陕西渭河平原地区乌类物种多样性研究   总被引:3,自引:0,他引:3  
胡伟  陆健健 《生物多样性》2001,9(4):345-351
1999年12月-2000年10月,按冬,春,夏,秋四季,在渭河谷地咸阳地区3个阶地上取有代表性的区域作样带调查,记录鸟类种类和数量,分析不同生境鸟类多样性及其变化规律,本次调查共记录到鸟类124种,隶属于15目35科79属,研究表明,该地区的鸟类总体α多样性水平较高,达3.2845,但不同季节各阶地的多样性水平不高,较高的β多样性指数反映了鸟类种类和组成在不同阶地间变化较大,阶地间多样性的差异表明我国渭河平原地区湿地对鸟类多样性有显著的影响,水是限制鸟类分布和栖息的重要因子。  相似文献   

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河南黄河湿地国家级自然保护区不同生境鸟类多样性分析   总被引:1,自引:1,他引:0  
2006年9月~2007年8月,对河南黄河湿地国家级自然保护区鸟类进行野外调查,结合文献共统计鸟类16目53科247种.对山地、滩地、水域、人工林4种生境鸟类物种数、鸟类数量等级、多样性、鸟类群落间相似性进行了分析.滩地鸟类物种数及G指数(属的多样性)和F指数(科的多样性)值均最高.山地和人工林鸟类组成有相似性.  相似文献   

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杨月伟  李久恩 《生态学报》2012,32(24):7913-7924
2010年10月至2011年9月期间,使用样线法对微山湖鸟类多样性进行研究.共发现鸟类132种,隶属13目39科,其中留鸟39种,夏候鸟33种,冬候鸟14种,旅鸟46种,分别占全部种类的29.6%、25.0%、10.6%和34.85%;国家二级保护鸟类有12种,省级重点保护鸟类16种,另外50种和16种鸟类分别列入中日、中澳候鸟保护协定.灰鹤、乌雕、沙鵖和白顶鵖4种鸟类在南四湖首次记录.根据微山湖的地理和植被状况,将研究区域划分为水域、次生林、农田和居民区4生境,不同生境中鸟类群落的Shannon-Wiener指数高低为沼泽水域>次生林>农田>居民区,Pielou指数高低为沼泽水域>农田>次生林>居民区.次生林和农田鸟类群落的相似性指数最高,沼泽水域与居民区的相似性最低.春季末期鸟类多样性指数和均匀性指数最高,秋季末期最低.冬季鸟类种类最多、密度最大,春初鸟类种类最少、密度最小.距居民区的距离、距公路的距离、植被盖度、人工池塘数目、水面积比例和深水面积比例等对鸟类多样性影响显著.  相似文献   

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邢台市及郊区鸟类区系组成及多样性   总被引:3,自引:0,他引:3       下载免费PDF全文
2003年3月~2005年7月对邢台市鸟类区系组成及多样性进行了调查,共记录到鸟类166种,隶属15目42科。本文重点探讨了不同生境、不同季节鸟类群落的种类、多样性、均匀度、相似性等群落特征。结果表明,鸟类种数由多至少依次为林地生境、公共绿地生境、河流水域生境、农田生境、建筑区生境。Shannon-Weiner多样性指数由大到小依次为林地生境、公共绿地生境、河流水域生境、农田生境、建筑区生境。比较这5种生境之间的相似性得出,公共绿地生境鸟类群落与建筑区生境鸟类群落、林地生境鸟类群落相似,相似性达到60%以上,而河流水域生境鸟类群落与其他生境鸟类群落有极明显的差异。  相似文献   

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Defects in mitochondrial energy metabolism have been implicated in the pathology of several neurodegenerative disorders. In addition, the reactive metabolites generated from the metabolism and oxidation of the neurotransmitter dopamine (DA) are thought to contribute to the damage to neurons of the basal ganglia. We have previously demonstrated that infusions of the metabolic inhibitor malonate into the striata of mice or rats produce degeneration of DA nerve terminals. In the present studies, we demonstrate that an intrastriatal infusion of malonate induces a substantial increase in DA efflux in awake, behaving mice as measured by in vivo microdialysis. Furthermore, pretreatment of mice with tetrabenazine (TBZ) or the TBZ analogue Ro 4-1284 (Ro-4), compounds that reversibly inhibit the vesicular storage of DA, attenuates the malonate-induced DA efflux as well as the damage to DA nerve terminals. Consistent with these findings, the damage to both DA and GABA neurons in mesencephalic cultures by malonate exposure was attenuated by pretreatment with TBZ or Ro-4. Treatment with these compounds did not affect the formation of free radicals or the inhibition of oxidative phosphorylation resulting from malonate exposure alone. Our data suggest that DA plays an important role in the neurotoxicity produced by malonate. These findings provide direct evidence that inhibition of succinate dehydrogenase causes an increase in extracellular DA levels and indicate that bioenergetic defects may contribute to the pathogenesis of chronic neurodegenerative diseases through a mechanism involving DA.  相似文献   

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The lactate dehydrogenase activity in reactions of lactate oxidation and synthesis was studied in subfractions of the chicken brain, heart and liver at the embryonal, early postembryonal and adult stages of development after thyroxine administration. It has been shown that during embryogenesis thyroxine predominantly enhanced the rate of lactate oxidation in the mitochondrial tissues. A marked increase in the lactate synthesis was found in cytoplasm of the adult chicken tissues. Specificity of enzyme activity alterations was detected in the chicken brain during ontogenesis after thyroxine administration.  相似文献   

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In order to determine if the absence of vitamin C in the diet of capybaras (Hydrochoerus hydrochaeris) causes scurvy, a group of seven young individuals were fed food pellets without ascorbic acid, while another group of eight individuals received the same food with 1 g of ascorbic acid per animal per day. Animals in the first group developed signs of scurvy-like gingivitis, breaking of the incisors and death of one animal. Clinical signs appeared between 25 and 104 days from the beginning of the trial in all individuals. Growth rates of individuals deprived of vitamin C was considerably less than those observed in the control group. Deficiency of ascorbic acid had a severe effect on reproduction of another population of captive capybaras. We found that the decrease in ascorbic acid content in the diet affected pregnancy, especially during the first stages. The results obtained suggest that it is necessary to supply a suitable quantity of vitamin C in the diet of this species in captivity.  相似文献   

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Somatostatin (SST) peptide is a potent inhibitor of insulin secretion and its effect is mediated via somatostatin receptor 5 (SSTR5) in the endocrine pancreas. To investigate the consequences of gene ablation of SSTR5 in the mouse pancreas, we have generated a mouse model in which the SSTR5 gene was specifically knocked down in the pancreatic beta cells (betaSSTR5Kd) using the Cre-lox system. Immunohistochemistry analysis showed that SSTR5 gene expression was absent in beta cells at three months of age. At the time of gene ablation, betaSSTR5Kd mice demonstrated glucose intolerance with lack of insulin response and significantly reduced serum insulin levels. Insulin tolerance test demonstrated a significant increase of insulin clearance in vivo at the same age. In vitro studies demonstrated an absence of response to SST-28 stimulation in the betaSSTR5Kd mouse islet, which was associated with a significantly reduced SST expression level in betaSSTR5Kd mice pancreata. In addition, betaSSTR5Kd mice had significantly reduced serum glucose levels and increased serum insulin levels at 12 months of age. Glucose tolerance test at an older age also indicated a persistently higher insulin level in betaSSTR5Kd mice. Further studies of betaSSTR5Kd mice had revealed elevated serum C-peptide levels at both 3 and 12 months of age, suggesting that these mice are capable of producing and releasing insulin to the periphery. These results support the hypothesis that SSTR5 plays a pivotal role in the regulation of insulin secretion in the mouse pancreas.  相似文献   

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