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。     

三峡重庆库区不同鸟类群落的物种组成及多样性研究

1996～1997年,对三峡工程重庆库区的鸟类群落物种组成和种群数量进行了调查,共调查记录库区鸟类15目48科226种,数量18929只。用鸟类数量级划分、Sorensen相似性指数、Shannon-Wiener指数和Pielou指数分析库区各种生境鸟类群落物组成和物种多样性结果表明：1）库区天然林、人工林、灌草丛和水域生境中鸟类群落的组成与农田生境具有较高的相似性,尤以人工林和农田的相似性最高;2）库区人工林生境鸟类群落物种多样性最高;3）库区由于长期以来人类活动的影响,生境日趋单一,已逐渐形成一种以农田灌丛鸟类为主的鸟类生态系统。     

盐城自然保护区新洋港河口不同生境冬季鸟类群落组成及其梯度变化

沿海湿地是鸟类重要的栖息地,人类活动导致的湿地生境变化对鸟类群落造成了一定的影响。在盐城自然保护区新洋港河口内,人类活动大体上导致了由陆向海方向,形成芦苇沼泽、农田、鱼塘和滩涂4种不同干扰程度的生境。分别在不同生境中设置3条长3 km的样线,对越冬鸟类的种类、数量进行了调查,运用多响应置换过程测试、指示种分析、双向聚类分析和除趋势对应分析等统计方法,研究了不同生境中冬季鸟类的指示物种、群落结构及梯度变化,结果表明:1)4种生境共记录鸟类67种,其中鱼塘生境的鸟类种类最多,为37种;滩涂生境的D'多样性指数在各生境不同时段中为最高,芦苇沼泽生境的H'多样性指数在各生境不同时段中为最高。与其余生境比较,芦苇沼泽、滩涂的均匀度也更高。生境间的差异性与鸟类群落的组成有关。2)MRPP分析表明,芦苇沼泽、农田生境的鸟类组成差异不显著(P0.05);其余组合各生境间的鸟类组成具有显著差异。灰鹤等9种鸟类可分别作为4种不同生境的指示种。3)双向聚类分析法把12种观测条件分为4大类,与生境划分非常吻合。在剩余信息40%水平上,鸟类可聚为7类。利用12种观测条件作为变量进行DCA排序的结果表明,鸟类类群在轴1上可以分为3个集群,分别为适应开阔水域环境的鸟类、依赖水生植被环境的鸟类和依赖陆地植被环境的鸟类。根据结果分析,生境异质性、干扰程度及潮水涨落等与鸟类多样性组成有密切关系;不同生境具有明显的指示种;鸟类群落结构为适应生境变化而出现一定的梯度变化。应加强芦苇沼泽的保护,在开垦农田、鱼塘和在光滩引入互花米草时应考虑到人类活动对鸟类多样性的影响。     

陕西省黄河湿地冬季鸟类群落初步研究

1998～2008年,采用直接计数法对陕西省黄河湿地冬季鸟类群落组成、鸟类物种多样性及数量变化进行了调查.在预先设置的5条调查样带中共记录到鸟类14目33科117种.观察结果表明,该地区鸟类多样性指数和均匀度指数分别为4.497和0.654.栖息地可分为人工渔塘、芦苇沼泽、滩涂湿地、农田和人工林5种类型.这些生境中鸟类组成及物种多样性差异均较大,其鸟类多样性指数分别为2.826、3.571、3.202、1.205、2.496,以芦苇沼泽中的鸟类多样性指数最高,滩涂湿地中鸟类数量最多,农田中鸟类优势度最高.通过对该地区鸟类群落组成及多样性分析研究以及黄河湿地冬季鸟类栖息地现状评价,为湿地鸟类资源的保护提供科学依据.     

杭州湾及钱塘江河口南岸滨海湿地鸟类群落多样性及其对滩涂围垦的响应

为了解杭州湾及钱塘江河口区域围垦过程中多种人工湿地对于鸟类的作用及在快速的土地利用方式转变过程中鸟类的响应过程,2008年11月至2011年9月,作者对上虞曹娥江口至镇海甬江口沿岸滨海湿地鸟类资源进行调查,共记录鸟类16目52科220种,其中候鸟173种,占总数的78.6％,属于国家Ⅰ、Ⅱ级重点保护野生动物的24种.对研究区域的8种生境的鸟类群落组成、多样性及相似性进行了比较.结果表明,记录物种数较多的生境依次为芦苇水塘(95种,占总数的43.2％)、海涂林地(93种,占总数的42.3％)、自然潮间带和海涂水库(均为78种,各占总数的35.5％),其他生境的物种数均不少于67种(占总数的30.5％以上);从不同鸟类类群的分布看,82.5％的鸻鹬类分布在自然潮间带,69.2％的雁形目鸟类出现在海涂水库,73.4％的雀形目鸟类分布在海涂林地,海涂林地也是大量鹭鸟的繁殖场所;与自然潮间带相似性系数最高的生境依次为围垦滞留区、海涂水库和芦苇水塘,相似性系数分别为0.56、0.34和0.30;从整体上看,海涂林地和海涂水库的鸟类群落G-F指数最高,自然潮间带最低,但水鸟G-F指数最高的生境类型依次为围垦滞留区、海涂水库和自然潮间带.围垦是目前对杭州湾鸟类动态影响最大的人为干扰活动,适度围垦和合理的垦后土地利用方式可能提高整个区域的鸟类多样性水平.为了有效保护杭州湾鸟类多样性尤其是依赖自然潮间带的鸟类多样性,应加强对滩涂资源的保护与可持续利用;在滩涂围垦过程中应尽量保留足够数量和面积的高潮停歇地;同时,加强对围垦滞留区的水位管理,并注重营造适合鸟类栖息的类型多样的围区人工湿地系统.     

长江师范学院校园夏季鸟类群落与多样性分析

2008年3～7月采用样线法对长江师范学院李渡校园鸟类组成和种群数量进行了调查,共记录鸟类6目21科28种,数量1633只,物种多样性指数为3．9204,均匀性指数为1．1765,其中国家“三有”名录鸟类25种,CITES名录鸟类1种。鸟类区系以东洋界成分为主。对不同生境鸟类多样性的分析结果表明：（1）乔灌林鸟类多样性指数和均匀性指数最高,水域鸟类多样性指数最低,建筑区均匀性指数最低;（2）乔灌林与竹林的相似性指数最高,竹林与水域的相似性最低。     

雅鲁藏布江中游地区土壤淡色丝孢菌群落多样性及物种生态位研究

从雅鲁藏布江中游地区采集土壤样品35份,主要涵盖农田、城市花园、高山草甸、湿地和防护林带五种生态类型,从中分离获得土壤淡色丝孢菌12属。利用种群优势度、Shannon-Wiener多样性指数、均匀度、生态位宽度、群落相似性等指标对该地区不同生境的土壤淡色丝孢菌物种(属级)的生态多样性及物种生态位进行了分析。结果表明,土壤淡色丝孢菌的数量和类群分布在该地区不同生态类型土壤中差异明显。农田生境中土壤淡色丝孢菌物种多样性指数最高,均匀度较高;防护林带生境中土壤淡色丝孢菌物种多样性指数最低,均匀度也最低。对不同生态类型土壤中淡色丝孢菌的相似性分析发现,农田和防护林带生境的相似性系数最大,说明这两种生境具有较多的共同物种;湿地和城市花园生境的相似性系数最小。物种生态位结果分析表明,在上述五种生境中,拟青霉属Paecilomyces、刺座霉属Volutella、曲霉属Aspergillus和青霉属Penicillium具有较宽的生态位宽度,属于广适性物种;而白僵菌属Beauveria和绿僵菌属Metarhizium生态位很窄,只存在于某个生境中,属于狭适性物种。     

四川老君山自然保护区不同生境鸟类多样性研究

2006年4~5月采用"点样带法"(point transects)对四川老君山自然保护区的鸟类物种组成和种群数量进行了调查,共记录到85种鸟类,分属7目22科。其中,国家级保护鸟类5种,我国特有种13种,优势种4种。把调查区域划分为3种生境:原始林、次生林和人工林,并对各生境鸟类群落的鸟类数量级、鸟类群落的物种多样性、鸟类群落间的相似性进行了比较分析,其结果表明:1)国家级保护鸟类在原始林中最多,次生林中最少;我国特有种则是次生林中最多,人工林中最少。2)鸟类群落Shannon-Wiener物种多样性指数原始林最高,人工林最低。3)原始林和次生林之间的B ray-Curtis相似性指数最高,原始林和人工林之间相似性指数最低。     

盐地碱蓬盐沼与相邻泥质滩涂湿地迁徙期鸻鹬类的群落组成及行为差异

盐地碱蓬(Suaeda salsa)盐沼湿地是黄渤海地区河口区域的重要湿地类型, 是水鸟迁徙停歇期的重要栖息地。本研究以辽河口国家级自然保护区为研究地点, 通过对盐地碱蓬盐沼湿地和相邻泥质滩涂两个固定样区连续三年的水鸟组成调查和行为观察, 分析盐地碱蓬盐沼湿地在鸻鹬类多样性维持和栖息地利用中的作用。共记录到鸻鹬类水鸟28种6,348只次, 其中盐地碱蓬湿地记录到4科13种, 泥质滩涂记录到4科27种, 泥质滩涂的物种多样性显著高于盐地碱蓬盐沼湿地。此外, 盐地碱蓬盐沼湿地与相邻的泥质滩涂的鸻鹬类鸟类群落组成存在较大差异, 盐地碱蓬盐沼湿地的鸟类群落组成以体型较大的大杓鹬(Numenius madagascariensis)、白腰杓鹬(N. arquata)、灰鸻(Pluvialis squatarola)等为主, 而泥质滩涂以环颈鸻(Charadrius alexandrinus)、黑腹滨鹬(Calidris alpina)等小型鸻鹬类为主, 这说明两种生境在鸟类多样性维持中具有不同的功能。行为分析发现, 泥质滩涂中栖息鸟类的主要行为为取食(58.71%-93.26%), 而盐地碱蓬盐沼湿地鸟类的行为既包括较大比例的取食, 也包括休息, 特别是在春季迁徙期。这进一步说明, 两种生境在水鸟的栖息地利用中具有一定的生态功能差异。尽管盐地碱蓬盐沼湿地记录到的鸟类物种数和数量均低于泥质滩涂, 但是, 两种生境中存在较大比例的共同分布物种, 这说明其生态功能具有较强的生态互补性, 二者作为一种独特的湿地景观组合, 在鸻鹬类迁徙停歇期的栖息地利用和物种多样性维持中发挥着不可替代的作用。     

长江中下游菜子湖湿地不同生境昆虫群落多样性

为研究菜子湖湿地不同生境中的昆虫群落多样性,并探讨昆虫对湿地过度围垦的响应,于2013年5—8月对菜子湖湿地的农田区、滩涂-草丛、草丛-灌木区的3种不同生境条件下的昆虫群落多样性进行了调查。共采集到昆虫7251只,隶属于8目89科207属235种。其中,双翅目、半翅目、直翅目为菜子湖湿地的优势类群,其个体数量分别占总个体数的27.61%、25.54%和15.96%。在3种生境中,昆虫种类丰富度在农田区生境中最高,其次是滩涂-草丛生境,在草丛-灌木区生境中最低;Shannon多样性指数和ACE估计值在3种生境之间的比较结果表明,滩涂-草丛与农田区差异显著,与草丛-灌木区无显著差异,农田区与草丛-灌木区差异显著。3种不同生境中昆虫群落的相似性指数平均值为0.25±0.02,表明植被类型和围垦显著影响昆虫群落多样性。     

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.     

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.     

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.     

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.