达赉湖自然保护区冬春季鸟类生物多样性与生境的关系

2004年4月-5月,利用样带法对达赉湖自然保护区5种主要生境类型中冬春季鸟类生物多样性进行了调查,利用Shannon-Wiener指数和Smith相关性系数分析了这5种生境类型中冬春季鸟类的生物多样性、区系、鸟类的群落组成、群落间的相似性和均匀度。结果表明,古北界鸟类是组成达赉湖鸟类群落的主体(约占冬春季鸟类的86%);芦苇湿地的鸟类多样性接近于芦苇甸的2倍:芦苇湿地鸟类群落的物种多样性最高(Shannon-Wiener指数为1.3001),而芦苇甸中鸟类群落的物种多样性最低(Shannon-Wiener指数为0.6629);芦苇湿地和芦苇甸两鸟类群落组成的相关性指数仅为0.038;从具有共同物种的多少考虑,典型草原和芨芨草原鸟类群落之间的关联较大。     

乌鲁木齐市不同生境繁殖期的鸟类群落多样性及功能集团分析

2016—2019年对乌鲁木齐市7种生境(高寒草甸、针叶林-灌丛、草原、农田、荒漠、湿地和城市公园)的繁殖期鸟类进行实地调查。共记录鸟类178种,隶属19目45科,其中雀形目Passeriformes最具代表性,共86种(占48.3%);居留型以夏候鸟和留鸟为主,共153种(占86.0%);分布型以古北型为主,共82种(占46.1%);珍稀濒危和重点保护物种共33种(占18.5%)。鸟类群落物种数及个体数最多的为湿地生境,荒漠、针叶林-灌丛生境次之,各生境物种数(H=30.628,P0.001)存在显著性差异。湿地生境鸟类的Shannon-Wiener多样性指数最高,高寒草甸生境的最低;草原生境的Pielou均匀度指数最高,高寒草甸生境的最低;高寒草甸生境的Simpson优势度指数最高,草原生境的最低;针叶林-灌丛生境的物种丰富度指数最高,荒漠生境的最低。草原与针叶林-灌丛生境之间的Sorensen相似性系数最高(0.59),高寒草甸与荒漠之间的最低(0)。湿地生境鸟类群落的捕食集团以食虫性为主,其他生境以杂食性为主。湿地生境中鸟类营地面巢的居多,高寒草甸生境中鸟类营洞巢的居多,其他生境中鸟类营编织巢的居多。上述结果表明,乌鲁木齐市周围的湿地生境应该得到优先保护。     

内蒙古中部地区繁殖鸟类多样性调查

2011年5～6月,采用样线法和固定半径样点法对内蒙古中部地区荒漠草原、典型草原及湿地3种生境中的鸟类进行了调查,共记录到繁殖鸟63种,隶属于11目25科,其中留鸟12种,夏候鸟51种。在动物地理区系成分上,古北界鸟类54种(占85.71%);东洋界鸟类9种(占14.29%)。调查结果表明,3种生境的鸟类群落结构在多样性指数上以湿地为最高,其次为荒漠草原,典型草原最低;均匀度指数最高的为荒漠草原,其次为湿地,典型草原最低。     

内蒙古包头南海子湿地鸟类群落组成及多样性

为了解包头南海子湿地鸟类资源现状,2006年8月至2007年10月,对内蒙古包头市南海子自然保护区的鸟类物种多样性和群落结构进行了调查,共记录到鸟类128种,隶属于15目37科.其中,古北界鸟类110种,占调查区鸟类种数的85.94%.居留型主要以夏候鸟和旅鸟为主.根据鸟类栖息地的生境类型,将保护区的鸟类划分为4个群落.其中,浅水沼泽的鸟类数量最多,多样性指数、均匀度指数均最高.南海子自然保护区对包头市生态旅游产业以及自然保护教育具有重要意义.     

陕西红碱淖湿地水鸟组成及多样性分析

2001年4月～2009年11月采用样线法和定点观察法对陕西红碱淖湿地鸟类进行了调查.共记录鸟类79种,隶属于8目14科,其中古北界56种,东洋界5种,广布种18种;在居留型上夏候鸟32种,旅鸟45种,迷鸟2种,无冬候鸟和留鸟.优势种以雁鸭类、鸥科、鸻鹬类为主.红碱淖湿地鸟类物种多样性指数为1.564,均匀度指数为0.361.在不同生境中,沼泽地鸟类群落多样性指数最高(1.561),均匀度指数为0.363,芦苇丛鸟类群落多样性最低(0.104),均匀度指数为0.050.分析了食物、生境和水位等因素对红碱淖湿地水鸟组成及多样性的影响.     

甘肃黑河内陆河湿地自然保护区候鸟多样性

甘肃黑河为我国第二大内陆河,位于其中游的黑河湿地自然保护区为内陆河流湿地生态系统自然保护区。2008年分季节采用样线法和样点法调查该保护区湿地、农田村庄、人工林和荒漠4种生境的鸟类种类和数量。调查共记录保护区分布的鸟类17目35科116种,其中夏候鸟73种(占鸟类种类的62.93%),迁徙过路鸟20种(占17.24%),留鸟17种(占14.66%),冬候鸟6种(占5.17%)。其中,属于《湿地公约》的水禽56种。在湿地生境共记录鸟类70种,占保护区鸟类种数的60.34%,其中繁殖期在湿地生境栖息的鸟类有50种,绝大部分为夏候鸟(47种),留鸟只有3种;迁徙季节分布有44种鸟类,其中迁徙过路鸟(只在迁徙季节见到)有17种,占迁徙季节鸟类种类数的38.64%。村庄农田、人工林以及荒漠生境中,繁殖期和迁飞期共记录鸟类57种,夏候鸟有33种,留鸟有17种,迁徙过路鸟只有3种。甘肃张掖黑河湿地保护区是众多水禽在我国西北地区的重要繁殖地和迁徙停歇地,是我国候鸟迁徙西部路线上的关键区域。     

宁夏沙坡头自然保护区四种生境夏季鸟类群落变化

1999年夏季采用样线法调查了宁夏沙坡头自然保护区 4种生境鸟的种数和数量 ,并与 1986年用相同取样方法得到的数据 (Liu&Chang ,1990 )进行比较 ,以了解 13年间鸟类群落的变化并探讨其原因。 1999年共记录到 6 7种鸟 ,比 1986年新增 36种 ,同时减少 10种。荒漠生境鸟类的数量减少到不足 1986年的 5 0 % ,但种数、群落多样性和优势度与 1986年接近 ;湿地生境鸟类的种数和数量都增加 1倍多 ,群落多样性和优势度略有增加 ;固沙林生境鸟类的种数从 8种增加到 34种 (增加了食虫、荒漠鸟类 ) ,但数量略减少 ,群落多样性增加 6 7% ,优势度减少 6 3% ;村庄农田生境鸟类种数与 1986年接近 ,数量、群落多样性和优势度都减少。湿地鸟类群落的状态变好 ,是鱼塘水域增加的结果 ;固沙林鸟类群落的状况看似好转 ,但潜伏着虫害所致的荒漠化危机 ;村庄农田生境鸟类群落状态变差 ,与农村传统土房大量消失有关。     

芜湖市冬夏季鸟类多样性分析

2004年5月至2005年2月,对芜湖市4种典型生境（农田居民区、城市园林、河漫滩湿地和河流湿地）的冬夏季鸟类进行调查,并探讨4种生境冬夏两季鸟类多样性指数.共记录鸟类117种,隶属于15目31科.农田居民区、城市园林和河漫滩湿地夏季鸟的种类数、G-F指数高于冬季,河流湿地冬季鸟的种类数、Shannon-Wiener指数、Pielou指数均明显高于夏季.城市园林鸟的种类数、G-F指数最高,河漫滩湿地Shannon-Wiener指数、Pielou指数最高.夏季的农田居民区和冬季的城市园林鸟类密度最大,分别为31.1140和42.9160 ind·hm^-2,而河流湿地鸟的种类数、密度、Shannon-Wiener指数、G-F指数均最低.增加栖息地异质性、减少人为干扰可以提高鸟类多样性.     

内蒙古乌兰察布地区鸟类区系组成及生态分布

2012年10月至2013年12月对内蒙古乌兰察布地区的鸟类区系及生态分布进行了调查研究。共记录到鸟类215种,隶属于17目48科。其中留鸟42种,夏候鸟101种,旅鸟67种,冬候鸟5种;繁殖鸟143种,构成区系的主体。繁殖鸟中古北界种类有118种,占繁殖鸟总数的82.5%,鸟类区系具有典型的古北界特征。国家Ⅰ级重点保护鸟类有5种,国家Ⅱ级重点保护鸟类有28种。依据地形地貌和植被类型,将该地区划分为湿地、林地、草地、农田、居民区5种生境,其中,湿地鸟类丰富度、多样性指数和均匀度指数最高,居民区鸟类丰富度、多样性指数和均匀度指数最低;优势度指数在居民区最高,在湿地生境中最低。从不同生境鸟类群落间β多样性的变化看,湿地与林地之间物种更替变化最大,群落相似性小;农田与居民区物种更替变化小,群落相似性大,与聚类分析的结果相一致。对该地区不同生境鸟类群落结构及其之间的关系进行了分析,探讨鸟类对栖息环境的选择以及鸟类与环境的关系。     

新疆木垒胡杨林区三种林分土壤真菌群落特征

采用T-RFLP、荧光定量PCR以及平板分离与鉴定等技术,分析了新疆木垒胡杨林区内胡杨过熟林、胡杨衰亡林及柽柳等植被下土壤真菌群落特征及其影响因素。结果表明:真菌群落结构差异在胡杨过熟林与柽柳之间最为明显,其次是胡杨过熟林与胡杨衰亡林;胡杨衰亡林、胡杨过熟林、柽柳分别具有最高的真菌丰富度指数、优势度指数和均匀度指数。3种林分土壤真菌数量在6.07×10~5~1.87×106copies·g~(-1)干土,胡杨过熟林土壤真菌数量显著高于胡杨衰亡林和柽柳。真菌丰富度、均匀度指数与pH呈正相关,优势度指数和真菌数量则与pH呈负相关。土壤pH显著影响了真菌的群落结构,其中胡杨衰亡林主要受pH和碳氮比的影响,而柽柳林受全氮的影响较大。上述结果表明:土壤真菌群落结构、多样性指数及数量在不同林分类型间存在明显差异,pH是影响真菌群落特征的关键因子。     

Role for dopamine in malonate-induced damage in vivo in striatum and in vitro in mesencephalic cultures

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.     

Changes in lactate dehydrogenase activity in chicken tissues in hyperthyreosis in ontogenesis

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.     

Scurvy in capybaras bred in captivity in Argentine

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.     

SSTR5 ablation in islet results in alterations in glucose homeostasis in mice

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.