119 resultados para NORTHEAST


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Poyang Lake (Poyang Hu) is located at the junction of the middle and lower reaches of the Yangtze (Changjiang) River, covering an area of 3283 km(2). As one of the few lakes that are still freely connected with the river, it plays an important role in the maintenance of the unique biota of the Yangtze floodplain ecosystem. To promote the conservation of Poyang Lake, an investigation of the macrobenthos in the lake itself and adjoining Yangtze mainstream was conducted in 1997-1999. Altogether 58 benthic taxa, including, 22 annelids, 8 mollusks, 26 arthropods, and 2 miscellaneous animals, were identified from quantitative samples. The benthic fauna shows a high diversity and a marine affinity. The standing crops of benthos in the lake were much higher than those in the river, being 659 individuals/m(2) and 187.3g/m(2) (wet mass) in the main lake, and 549 individuals/m(2) and 116.6 g/m(2) in the lake outlet, but only 129 individuals/m(2) and 0.4g/m(2) in the river. The dominant roup in the lake was Mollusca, comprising 63.4% of the total in density and 99.5% in biomass. An analysis of the functional feeding structure indicated that collector-filterers and scrapers were predominant in the lake, up to 42.2% and 24.7% in density and 70.2% and 29.2% in biomass, respectively, while shredders and collector-gatherers were relatively common in the river. The present study was restricted to the northern outlet and the northeast part of Poyang Lake. A scrutiny is required for the remaining areas.

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We present multi- frequency radio observational results of the quasar 3C 48. The observations were carried out with the Very Large Array ( VLA) at five frequencies, 0.33, 1.5, 4.8, 8.4, and 22.5 GHz, and with the Multi- Element Radio Linked Interferometer Network ( MERLIN) at the two frequencies of 1.6 and 5 GHz. The source shows a one- sided jet to the north within 1", which then extends to the northeast and becomes diffuse. Two bright components ( N2 and N3), containing most of the flux density, are present in the northern jet. The spectral index of the two components is alpha(N2) similar to -0.99 +/- 0.12 and alpha(N3) similar to - 0.84 +/- 0.23 ( S proportional to nu(alpha)). Our images show the presence of an extended structure surrounding component N2, suggestive of strong interaction between the jet and the interstellar medium ( ISM) of the host galaxy. A steep- spectrum component, labelled S, located 0.25 " southwest to the flat- spectrum component which could be the core of 3C 48, is detected at a significance of > 15 sigma. Both the location and the steepness of the spectrum of component S suggest the presence of a counter- jet in 3C 48.

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受人类对土地过度垦殖及不合理耕作利用的影响,水土流失正在成为制约我国东北地区耕地可持续利用和粮食生产的主要因素。在对历史资料甄别与整理的基础上,分析近代以来东北3省区人口、土地利用变化及其与水土流失关系的演变。结果表明:到20世纪中期,东北地区人口压力达到60~70人/km2,伴随着生活方式的转变,机械化技术的应用,林草湿地被垦殖,森林覆盖率降到30%,垦殖率达30%,使区域性水土流失问题日益严重。

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目前激光衍射法(laser diffraction method,LD)逐步被用于土壤颗粒粒径分布(particle size distribution, PSD)的分析,为了对比LD法和吸管法测定东北黑土区土壤PSD的差异性,采用LD法和吸管法分别对东北黑土区宾州河流域36个土壤剖面不同层次178个土壤样品的PSD值进行了测定与分析。结果表明,同吸管法相比,LD法低估了土壤的黏粒含量,平均低估幅度19.69%,而高估了土壤的粉粒和砂粒含量,平均高估幅度分别为14.66%和5.13%。LD法所得PSD结果依据美国土壤质地分类制判定的土壤质地,相对于吸管法总体由粉黏质偏向粉砂质方向。建立了LD法与吸管法测定PSD结果的转换模型,将LD法测定的PSD结果利用转换模型校正后,其测定的各土壤粒级同吸管法相比,准确度达96.97%~98.71%,判定土壤质地的准确率也达83.15%。

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土壤有机碳、全氮的空间分布及特性研究一直是土壤学研究的热点,研究东北黑土有机碳、全氮的空间分布和特性可以为东北黑土退化机理及可持续利用提供理论依据。本文以东北黑土区1200个样点为基础,依据尺度分布理论,采用宏观统计分析和微观化学分析相结合,研究了黑土有机碳、全氮空间分布规律;黑土有机碳与其它养分之间的关系;黑土有机碳、全氮在团聚体中的富集以及黑土活性有机碳、氮的区域分布特性。本次研究是继第二次土壤普查以来对黑土有机碳系统研究,首次摸清了东北黑土有机碳库的现状和分布规律,及其与其它养分库的关系,采用经典统计学方法绘制了黑土有机碳空间分布图;对影响有机碳库和养分的驱动因素进行了分析,发现了黑土有机碳库的“经向”和“纬向”分布规律;总结了黑土有机碳库频数分布特征,以及自第二次土壤普查以来几十年间的变化。探讨了土壤有机碳空间分布的驱动因子,绘制了土壤有机碳、全氮的空间分布等值线图,阐明了土壤活性有机碳、氮库的空间分布对土壤有机碳库的贡献: 1、土壤有机碳、全氮水平空间分布在纬向上主要受温度控制,在经向上主要受水分控制,黑土有机碳与纬度的显著相关(r=0.70188, P<0.01),与黏粒显著正相关(r=0.43, P<0.01),与砂粒显著负相关(r=-0.44, P<0.01)。 2、土壤有机碳、全氮垂直空间分布在一定深度内受温度控制,水分状况作用较小,黏粒在深度剖面作用不显著,随着土壤深度的增加,土壤有机C和全N含量降低。 3、土壤团聚体组分中有机碳、全氮含量与纬度呈正相关关系,大团聚体和微团聚体更易受水热条件影响,大团聚体的有机碳富集因子E≥1的趋势明显而微团聚体及粉+黏组分有机碳的富集因子E≤1的趋势明显,说明大团聚体中有机碳具有累积趋势而微团聚体和粉+黏组分中有机碳处于消耗状态。 4、黑土其它养分的分布均非正态分布,有机碳与全磷、全钾、碱解氮、速效钾和速效磷之间的相关关系分别为0.795、-0.295、0.801、0.244和0.036,只有有机碳和速效磷之间没有相关性,而与其它养分在P<0.01水平呈显著相关。 5、土壤活性有机碳和活性有机氮随纬度增加活性组分增大,土壤活性有机碳的比例较小,说明黑土有机物料输入较低;黑土活性有机氮含量差别不大,说明微生物活动相似。

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城市扩展及其导致的土地利用/土地覆被变化作为全球环境变化的重要驱动因素,日益引起社会各界的普遍关注。新中国成立以来,沈阳市经历了快速的城市化过程,特别是进入21世纪以来,伴随着人口增长和经济发展,中心城区持续向外扩张,导致基本农田大量流失,区域景观和生态环境质量日益下降,给沈阳市的城市增长管理和可持续发展带来严峻挑战。 利用遥感(RS)、地理信息系统(GIS)和空间Logistic回归模型对1988-2004年间沈阳市的城市扩展与土地利用变化特征及其驱动力进行深入分析,并在此基础上利用基于细胞自动机(CA)的城市扩展模型-SLEUTH对历史时期(1988-2004年)的城市扩展格局进行模拟与重建,对未来(2005-2030年)不同发展条件下的城市扩展进行模拟与环境影响评估,以期为城市增长管理与区域可持续发展提供决策支持。本论文取得如下研究成果: (1) 1988-2004年间,沈阳市辖区城市面积持续增加,城市扩展强度逐渐增强;2000-2004年城市扩展规模和强度都达到最大;沈阳市城市化进程正在显著加速。城市扩展具有明显的空间分异特征:整个研究时段内,市区西南方向是城市扩展的主方向,中心城区周边(8~10km)及各级经济开发区是扩展的热点区域。 (2) 1988-2004年间,沈阳市辖区土地利用变化最主要的特征是耕地向城乡建设用地的大面积转换。持续的城市扩展导致区域景观日益破碎化和复杂化。城市和其它建设用地的景观影响日益增强,耕地的优势地位减弱,且破碎化程度增加,斑块形状日趋复杂。城市化空间梯度上的土地利用格局变化分析表明,随着城市化水平的提高,景观组成和空间配置发生了明显变化。处在城市化前沿区域的城郊地区,景观格局表现出景观多样性增加、破碎化程度加深和形状日趋复杂等特点。 (3) 1988-2004年间,沈阳市辖区城市扩展主要受到社会经济发展的推动作用和政策因素的激励与导向作用。空间Logistic回归分析显示,开发区建设与行政建制变化、道路与城镇分布、浑河和城市规划是城市空间扩展的主要影响因素。 (4) ROC曲线统计、Kappa统计与多分辨率误差估算以及景观指数从城市扩展总体预测能力、增长数量、空间位置和空间格局上给予SLEUTH模型一个全面、客观的评估。总体上来说,SLEUTH模型具有可信精度,较好地表达了沈阳市1988-2004年间城市扩展的总体趋势,对城市扩展面积的拟合精度很高。但是,与其它城市扩展模型相似,在像元尺度上对城市扩展空间位置的预测和对城市空间格局的表达还有待于提高;随着分辨率的降低,模型对城市发展中空间邻域关系的表达效果趋于提高。SLEUTH模型对城市扩展的总体模拟精度要高于空间Logistic回归模型,但是对城市扩展位置的模拟准确性低于后者。 (5) 通过分析发现,影响SLEUTH模拟准确性的主要因素包括模型结构、地方城市发展特征、模型应用的时空尺度和模型输入数据的获取与误差传递等。通过修改模型组分设置、开展模型敏感性与不确定性分析以及实行城市扩展一体化模拟可以提高SLEUTH模型的模拟效力,而具体实现方法需要深入研究。基于模型评估结果和效力提高的对策,对城市扩展演变的时空格局进行了较为准确的重建,为其相关研究提供了可靠的历史数据资料。 (6) 遵循沈阳市目前和未来的区域开发政策、最新修编的城市总体规划,以及社会对区域生态环境保护的要求,设计了五个城市发展预案,即目前趋势发展预案(CT)、区域开发政策与城市规划预案(PP)、生态可持续发展预案(ES)、紧凑式发展格局预案(CD)和特定增量发展预案(GA)。对不同预案条件下未来(2004-2030年)城市扩展面积和空间格局、城市扩展热点区域、城市景观格局变化及其景观生态效应,以及对其它类型土地资源的消耗四个方面进行了分析和比较,为沈阳市城市规划、生态建设以及可持续增长管理提供了许多有价值的决策信息。

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研究森林净第一性生产力(NPP)对全球气候变化的响应,是了解全球气候变化与森林生态系统相互作用关系的关键。本文在分析长白山、丰林、呼中三个研究区气候变化特征的基础上,运用生态系统过程模型PnET-II模型,模拟东北主要森林的NPP过去43年来的动态,并结合动态GCM结果(CGCM2)预测未来一百年东北主要森林NPP的变化趋势。通过与实测数据和文献资料的对比,结合模型敏感性和不确定性分析,验证和探讨了模拟结果的准确性。主要结论如下: (1)近43年的气候变化趋势表明,三个研究区的气温都有上升趋势。丰林和长白山地区20世纪90年代后期增温明显,但降水减少,表现出暖干化趋势。呼中地区90年代后的降水减少趋势并不明显,表明东北的暖干化趋势存在地区差异。未来近100年气候变化趋势预测表明,三个研究区的日最低温和日最高温都有明显的增加趋势,日最低温的增幅大于日最高温。未来100年气温变化可分成两个阶段,21世纪前半叶温度增幅较小,而后半个世纪增速明显加快。与温度的增加趋势相反,21世纪光合有效辐射有明显的下降趋势。三地的降水在21世纪都有增加,但具体年际变化趋势有差异。这些与森林生长密切相关的气候因子的变化,将会给该地区的森林生态系统带来深刻的影响。 (2)模型估算三个地区主要森林NPP值,过去43年来有下降趋势,但不显著,而且存在年代际间波动。未来一百年,随着气候变暖,三地所有森林的NPP值都有不同程度的降低,2050年前NPP变动幅度较小,2050年后有较明显的减少趋势。 (3)模拟CO2浓度增加和气候变化对NPP的双重影响,丰林和长白山的红松林和硬阔林的NPP有不同幅度的增加,而云冷杉林和落叶松的NPP都减少。气候变化对云冷杉和落叶松林的生产力影响较大。 (4)植被参数的敏感性分析表明,与光合作用有关的植被参数对NPP的预测结果影响较大;对气候参数的敏感性分析表明,森林NPP对温度的反应敏感。 (5)通过与实测值的比较,结果表明PnET-II模型能较准确地估算东北森林净第一性生产力;与其它已有文献的比较其结果表现不一,其中一个重要原因可能是PnET-II模拟时未考虑氮碳循环过程导致。

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本文对东北地区松辽平原不同纬度农田土壤碳氮磷剖面分布特征进行比较研究,从北到南依次采集了黑土区的海伦、哈尔滨、德惠、公主岭和棕壤区的昌图、沈阳、大石桥玉米地土壤样品。所得主要结论如下: 各样点土壤有机碳含量随土层深度的增加而下降。海伦、哈尔滨和公主岭样点40~60cm土层土壤有机碳含量及其储量显著低于0~40cm土层;海伦、哈尔滨、德惠、公主岭和昌图样点土壤水溶性有机碳表现出随深度增加先升高后降低,在沈阳和大石桥样点土壤水溶性有机碳表现出随深度而下降的趋势;各样点0~20cm土层土壤微生物量碳含量高于20~40cm土层。典型黑土区海伦点0~100cm的SOC储量为213.4t•hm-2, 棕壤区昌图、沈阳、大石桥样点分别为69.9、87.9和73.4t•hm-2,海伦点SOC储量是棕壤区三样点的3倍左右。 土壤全氮、碱解氮、硝态氮及氮储量随剖面深度增加而下降。德惠点在20~40cm土层、沈阳点在40~60cm土层、昌图点在60~80cm土层的全磷含量最低;其他样点土壤全磷、有机磷含量和磷储量总体上呈现随土层深度增加而下降的趋势。黑土区样点土壤有机磷含量在40cm以下各土层迅速下降,而棕壤区各样点20cm以下各土层差异不显著。除公主岭和大石桥点外, 其他各样点土壤Olsen-P含量在0~20cm 土层显著高于20~40cm土层。 土壤有机碳、全氮、碱解氮、全磷和有机磷含量随纬度增加而增加。营养元素在纬度上的分异主要受成土母质、气候条件等自然因素影响,施肥、耕作等人为活动对表层土壤营养元素分布的影响较大。除土壤水溶性有机碳外,土壤碳、氮和磷之间及其与其他基本理化性质间均存在显著的相关关系。

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生态系统服务评价可清晰地揭示生态环境问题产生的经济根源。由于生态系统服务的复杂性、多样性、重叠性,需选择合适的研究尺度及方法才可使评价结果进入管理、决策过程。 本文以本溪县森林生态系统服务评价为例,确定适合县域尺度的评价方法,借助GIS技术,揭示森林生态系统提供林木生产、水源涵养、土壤保持、气体调节等四种服务的物质量、价值量及其空间分布规律。不同生态系统服务空间分布规律的研究对于维护和提高区域森林生态系统提供生态系统服务能力具有重要意义。主要研究结果如下: (1)研究区森林面积2.72×105ha,以天然次生林为主,中、幼龄林比重较大,森林郁闭度大。按优势树种可划分为蒙古栎、落叶松、色木、胡桃楸、红松、油松、千金榆、枫桦和杂木林等九种类型。 (2)研究区森林生态系统活立木生长量为2.56 m³•ha-1•a-1,森林水源涵养量为873m³•ha-2,土壤保持量为6.77 t•ha-1•a-1,固定CO2为5.15t•ha-1•a-1;活立木生产价值为200元•ha-1•a-1,水源涵养价值为611元•ha-1,土壤保持经济价值为663元•ha-1•a-1,固定CO2为6411元•ha-1•a-1;研究区总活立木生产价值为5.43×107元•a-1,水源涵养价值为1.66×108元,土壤保持价值为1.80×108元•a-1, CO2年固定价值1.74×109元•a-1。 (3)生态系统服务价值较高的区域在研究区中部偏南、偏北集中分布,在南部、东南部零星分布。

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本文采用以世界自然保护联盟(IUCN)濒危物种等级和标准为依据的中国物种红色名录确定出东北地区濒危植物。统计整理出濒危植物地理分布资料,通过对受威胁系数及遗传价值系数等系数的计算得到各个濒危种的优先保护值和保护等级,并以丰富度、优先保护值为指标运用不同方法得到的濒危植物保护的热点地区。主要结论如下: 东北地区共有濒危植物25科42属60种,其中中国特有种8种。濒危植物科属种三个层次植物区系是温带性质的。 应用多指标的优先保护值进行综合分析,将60种濒危植物划分了3个保护等级。一级保护的有长白松等11科14属18种;二级保护的有朝鲜梾木等12科16属19种;三级保护的有鱼鳞云杉等13科17属23种。 针对保护濒危植物丰富度高的县市和达到对所有种保护的目标,并综合考虑濒危植物受威胁程度、遗传价值、利用价值、保护现状和名录收录的因素,本文确定6个地区包含的19个县市作为本文濒危植物优先保护区域。优先保护区域如下:长白山的安图县、抚松县、长白朝鲜族自治县、临江市、和龙县和靖宇县,辽东山地的宽甸满族自治县、桓仁满族自治县、本溪满族自治县、清原满族自治县、新宾满族自治县、凤城市、庄河市和大连市,小兴安岭的伊春市,张广才岭的尚志市,老爷岭北部的鸡西市,大兴安岭的呼玛县和根河市。 本文首次以县市为单位对各县市自然保护区进行综合评价并划分综合评价级别。确定的优先保护区域中有4个县市对濒危植物的保护尚属空白,它们是临江市、和龙县、本溪满族自治县和鸡西市,建议采取措施对这些县市的濒危植物种加强保护。应通过对自然保护区晋级方式加强保护的有安图县的长白松保护区和根河市的西伯利亚五针松保护区。应加强辽东山地的除国家级自然保护区外的其它类型自然保护区中濒危植物的保护。

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该文结合中国天然林保护工程的新形势和森林可持续发展的要求,运用林学、群落生态学、恢复生态学、生物多样性保护等原理和方法,以长白山区广泛分布于中低海拔的次生林为研究对象,通过大量的野外调查、室内分析和资料收集,针对实际深入研究和评价了在自然恢复和人为抚育管理模式下次生林的动态及其过程的一些重点问题,进而揭示了在不同管理模式下次生林群落组成、结构、物种多样性、种群分布格局、种间联结等演变规律及其对森林稳定性的贡献和维持机理,丰富和补充了阔叶红松林的系统研究内容,为林区森林的发展提供了模式和依据.

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生态系统健康(学)是当前生态系统学和环境管理的研究热点,生态系统健康评估是生态系统健康(学)的主要研究内容之一。好的可操作的评估理念和技术手段是推动生态系统健康(学)研究的重要因素和内在要求。不合理的林业生产是全球森林生态系统健康程度降低的最主要因素之一。人为强度砍伐干扰直接导致林区森林面积减少、生物多样性严重破坏、资源短缺危机、森林生态系统健康程度急剧下降、提供的生命支持系统功能显著减弱。本文以长白山林区典型森林生态系统一阔叶红松林为例,提出并运用了相关森林生态系统健康评估理论和技术,进行了定量的评估研究。以期为区域森林生态系统健康管理和生态系统健康学的发展提供借鉴。研究表明:(1)通过建立恰当的概念,选择合适的原始阔叶红松林作为生态系统健康基准是可行的,并且是进行健康评估的基础;(2)干扰造成群落垂直结构、水平结构、生物多样性、生物量等具体指标的变化,导致阔叶红松林生态系统健康现状降低;(3)群落尺度上,指示物种和指示类群等生态指示法是评估生态系统健康的有效方法;(4)健康的森林生态系统是一个模式生态系统集,利用健康距离和指标体系可以在群落尺度或区域等更大尺度上对森林生态系统结构、功能、活力等多个特征进行单独或综合性健康评估;(5)综合构成指数也是一个森林生态系统健康评估的有效的方法,它在揭示森林生态系统群落结构动态和演替发展趋势上具有优越性;(6)砍伐干扰对原始森林生态系统健康具有严重破坏性。

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本文通过室内模拟培养试验的方法,以东北典型的四种土壤黑土、白浆土、棕壤和褐土为供试对象,研究它们在不同的土壤温度(10℃、20 ℃ 30 ℃)和不同的土壤湿度条件(10%、20%、30%)下过氧化氢酶、脱氢酶、多酚氧化酶催化动力学特性的变化。本文的主要结论是:1.黑土、白浆土、棕壤和褐土在不同的土壤温湿度条件下所测得过氧化氢酶、 脱氢酶、多酚氧化酶的Km值均高于相应纯酶制剂的Km值,表明土壤中的这三种氧化还原酶以固定态的形式存在。2.土壤过氧化氢酶、脱氢酶、多酚氧化酶的Vmax/Km值均随土壤温度的升高而增大,表明温度升高,它们的催化活性增强。3.土壤过氧化氢酶、脱氢酶、多酚氧化酶的动力学参数未见随土壤湿度的增大而呈现一致的变化趋势,表明酶的催化能力对土壤湿度变化的响应并不敏感。4.不同酶的动力学参数与土壤性质间的相关关系在不同的土壤类型以及不同的温湿度条件下不同,是不同土壤间及同一种土壤在不同的温湿度条件下各种物理、化学和生物化学特性存在巨大差异的结果。

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对隆肛蛙属的物种构成进行了订正,建立新属肛刺蛙属Yerana gen. nov.;订正后的隆肛蛙属现仅隶2种, 即隆肛蛙F. quadrana和太行隆肛蛙F. taihangnicus。运用形态学分析探讨了隆肛蛙属物种及种群的形态差异和分类关系,通过分子系统学研究探讨了隆肛蛙属物种及种群的分类和系统发育关系,运用动物地理学方法结合系统发育关系探讨了隆肛蛙属种群的地理分布格局成因与历史过程。主要结果和推论如下: 1.隆肛蛙属物种构成的订正及一新属建立 建立新属肛刺蛙属,将隆肛蛙属中的原叶氏隆肛蛙F. yei归隶新属肛刺蛙属并更名为叶氏肛刺蛙Y. yei,,新属建立的主要依据为:(1)雄性肛部隆起,肛孔下方有两个布满黑刺的大的白色球形隆起,具单咽下内声囊, 第一指具婚刺;(2)形态量度分析表明叶氏肛刺蛙与隆肛蛙和太行隆肛蛙的形态差异远大于后两者之间的差异;(3)叶氏肛刺蛙的分布区与隆肛蛙和太行隆肛蛙的分布区距离较远且呈隔离状态;(4)分子系统学研究资料(Jiang et al.,2005)证明叶氏肛刺蛙与隆肛蛙和太行隆肛蛙非单系发生;叶氏肛刺蛙在第二支中位于基部。因此,隆肛蛙属现仅隶2种,即隆肛蛙和太行隆肛蛙。 2.隆肛蛙属种群形态学研究 对隆肛蛙属中隆肛蛙和太行隆肛蛙的15个地理种群565只标本的28项形态性状进行了测量,运用典型判别分析法对其分析的结果表明:(1)太行隆肛蛙与隆肛蛙形态差异明显,支持其为不同的物种;(2)原隆肛蛙河南伏牛山种群和山西中条山种群应为太行隆肛蛙的地理种群;(3)隆肛蛙不同地理种群之间形态差异明显,其中四川安县种群、陕西周至种群和湖北利川种群与模式产地重庆巫山种群的差异可能达到了亚种或亚种以上分化水平。对隆肛蛙属量度分析的15个种群进行定性形态分析表明其分为三种形态型,对应隆肛蛙、过渡型和太行隆肛蛙,其变异特征主要为内跗褶、雄性肛部隆起及疣粒分布、第五趾外侧缘膜等,这与量度分析结果相似。 3.隆肛蛙属种群分子系统学研究 测定隆肛蛙属Feirana的2种19种群的线粒体12S rRNA和16S rRNA基因片段、ND2基因的DNA序列,比对后共计1953bps。(1)遗传多样性与距离分析:结果表明,隆肛蛙属种群具很高的遗传多样性,19个种群样品表现出19种单倍型(遗传多样性指数Hd=1.0); ND2基因的进化信息含量远高于12SrRNA和16SrRNA。隆肛蛙属2种群组内的种群间的遗传距离远小于两种群组间的距离,种群在不同基因上的遗传距离表现的关系与对应的系统树一致。(2)系统发育关系分析:结果表明,不同基因片断基于不同方法构建的隆肛蛙属种群系统发育树结构基本一致,基本表明隆肛蛙属种群为单系发生;它们在系统树中分为两大支,分别对应于隆肛蛙和太行隆肛蛙;支持中条山种群(沁水、历山和济源种群)和伏牛山种群(栾川和内乡种群)为太行隆肛蛙的地理种群,而原隆肛蛙秦岭中东段的部分种群(柞水、宁陕、长安大坝沟种群)也应为太行隆肛蛙的地理种群。(3)亚种分化分析:根据遗传距离分析和系统发育关系分析结果,并考虑形态上的差异情况以及地理分布信息,隆肛蛙所隶种群组可分为2亚种,即隆肛蛙指名亚种F. quadrana quadrana包括四川盆地东缘大巴山东段-巫山-武陵山北麓种群和秦岭中段(周至板房子和长安广货街)种群,他们在系统关系树上聚为一支;安县亚种F. quadrana anxianensis包括四川盆地西缘岷山东麓-龙门山-大巴山和秦岭西段的种群(安县、青川、文县、南江和凤县种群),他们在系统关系树上聚为一支。太行隆肛蛙所隶种群组也可分为2亚种,即太行隆肛蛙指名亚种F. taihangnicus taihangnicus包括中条山的种群(沁水、历山和济源种群)和中东秦岭的部分种群(柞水、长安大坝沟和宁陕种群),他们在系统关系树上聚为一支;太行隆肛蛙伏牛亚种F. taihangnicus funiuensis,为伏牛山地区的种群(栾川和内乡种群),他们在系统关系树上聚为一支。 4.隆肛蛙属种群动物地理学研究 隆肛蛙属19种群的分歧年代分析: 以长江巫山段和黄河三门峡段的形成历史时期为参考点,根据已测隆肛蛙属19种群及其外群包括N. pleski、P. yunnanesis、P. robertingeri、F. limnocharis的1953bps DNA序列构建分子钟,获得各支系的分歧年代。结果表明:①棘蛙族在70Ma左右开始其独立演化历程,这与Roelants et al.(2004)的分析结果~60±15Ma左右开始分化基本一致,后者印证了本文的分子钟。②隆肛蛙属的起始分化年代较早,隆肛蛙和太行隆肛蛙两种群组的最近祖先种群大概在46Ma~50Ma左右;隆肛蛙和太行隆肛蛙种群组内的种群分化年代相对两种群组间晚得多, 隆肛蛙种群组内两亚种分化起始年代约为10Ma左右,而太行隆肛蛙种群组内两亚种分化起始年代约为6Ma。 隆肛蛙属种群分布格局形成过程分析: ①隆肛蛙属的系统关系与地理分布格局密切相关,大部分系统分支分级与地理距离成正比;②隆肛蛙属最近祖先种群的分化中心可能位于秦岭中部地区, 隆肛蛙属的种群分布格局的形成表现为隔离分化与扩散相结合的机制,由隔离分化产生的隆肛蛙祖先种群主要从秦岭中部向西南方向扩散,后隔离分化为两亚种;太行隆肛蛙祖先种群向东北方向扩散也分化为两亚种。 隆肛蛙属种群分布区域地质历史的探讨:本文所建分子钟和种群分化方式印证了该区域的几次主要地质事件,包括岷山-龙门山-西秦岭等地区的快速差异隆起、第四纪冰期等。 The specific composition of the genus Feirana should be revised. A new genus Yerana gen. nov.(Ranidae:Dicroglossinae)was established based on morphological data-set and molecular phylogeny, as a result, only two species F. quadrana and F. taihangnicus are classified into Feirana now. Morphological differences and taxonomy of populations of Feirana were investigated based on morphological and morphometric data; phylogenetic relationships and taxonomy of populations of Feirana were elucidated using molecular data, and then the proceeding of the distribution pattern of populations of Feirana were discussed. The main results and conclusions and proposals were presented as following: 1. Revising of the specific composition of the genus Feirana and establishment of a new genus The new genus Yerana, only containing the type species Y. yei, was established based on the following evidences: (1) In adult male, distinct up-heaved circular vesicle presents around the anal, and under anal there are two white balls on which black spines exist, black horny spines scatter on the upper side of first finger, and internal single subgular vocal sac presents; (2) there is obvious morphometric differences between Yerana and Feirana; (3) Yerana is distributed far from Feirana; (4) evidences of molecular phylogeny(Jiang et al.,2005)suggested that Yerana take a special phylogenetic clade which is different from other genus included in the tribe Paini. As a result, there are only two species in Feirana, i.e., F. quadrana and F. taihangnicus. 2. Morphological research of populations of Feirana Twenty-eight characters of 565 individuals of 15 populations of the genus Feirana were measured, the results of Canonical Discriminant analysis of the morphometric data-set indicated that: (1) there are very prominent differences between the two species F. quadrana and F. taihangnicus. The validity of species F. taihangnicus was approved here; (2) Mt. Funiu population and Mt. Zhongtiao population should belong to the species F. taihangnicus; (3) Obvious differences exist among 12 populations of F. quadrana, the differentiation among Zhouzhi population, Anxian population, Lichuan population, and Wushan population together with the others probably reach sub-specific or specific level. Result of morphological comparison between 15 different populations show that 3 morphological types are recogenized in according with F. quadrana, F. taihangnicus and intergradation, this result conform to the result of morphometric analysis. 3. Molecular phylogenetic study on populaions of Feirana Fragment of 12SrRNA and 16SrRNA genes, and ND2 gene of 19 populations of two species of Feirana were sequenced and aligned, from which 1953 bps were received. (1) analyses of genetic distance and hereditary diversity indicated that: genetic distance between populations in each group were less than distance between two groups of Feirana, 19 haplotypes were recognized from 19 samples of 19 populations, so the hereditary diversity of populations of Feirana was very high (Hd=1.0), phylogenetic information in ND2 gene is more than fragment sequence of 12SrRNA and 16SrRNA genes. (2) Result of molecular phylogeny indicate that the phylogenetic trees constructed using different methods based on different sequence data sets showed the revised genus Feirana is monophyletic since the 19 populations of Feirana were firstly clustered together as one large clade, which was further clustered into two major clades, corresponding to F. quadrana(GroupⅠ) and F. taihangnicus(GroupⅡ), respectively. So populations of Qinshui and Lishan in Mt. Zhongtiao, populations of Luanchuan and Neixiang in Mt. Funiu, and populations of Zhashui, Dabagou of Chang’an and Ningshan in eastern Mt. Qinling should belong to the species F. taihangnicus; (3) Subspecific differentiation. on the basis of genetic distance, phylogenetic trees and geographical distribution, F. quadrana should have two subspecies, i.e., F. quadrana qudadrana, consisting of the populations Guanghuojie of Chang’an and Zhouzhi in Mid-Mt. Qinling, populations in Wushan area and northern Mt. Wuling (Lichuan), and F. qudadrana anxianensis, consisting of the populations in eastern Mt. Ming shan-Mt. Longmen-western Mt. Daba-western Mt. Qinling (Anxian, Qingchuan, Wenxian, Nanjiang and Fengxian); F. taihangnicus should also has two subspecies, i.e., F. taihangnicus taihangnicus, consisting of the populations in Mt. Zhongtiao and eastern Mt. Qinling, and F. taihangnicus funiuensis, consisting of the populations in Mt. Funiu. 4. Zoogeography of populaions of Feirana Analysis for divergent time of 19 populations of Feirana: Using the dates of run-through of Wushan segment of Changjiang River as the time when the population of Lichuan started differentiated from the populations of Wushan and Shennongjia, and the dates of Sanmenxia segment of Yellow River as the time when the populations in Mt. Zhongtiao started differentiated from the population of Dabagou in Chang’an, molecular clock was established using sequences with 1953 bps of 19 populations of Feirana and outgroup including N. pleski, P. yunnanesis, P. robertingeri, F. limnocharis in order to estimate divergent time of all clades. Result of that indicated that: ① the tribe Paini started to evolve independently at about 70Ma when is in consistent with that estimated by Roelants et al.(2004)with result of about ~60±15Ma, they were corroborated by each other, this confirms the validity of this molecular clock; ② divergent time for speciation of Feriana is early, ancestral populations of F. quadrana and F. taihangnicus were found about 46Ma~50Ma; differentiation of populations within species is greatly late to the divergence of the two species, divergent time for F. quadrana is 10Ma and divergent time for F. taihangnicus is 6Ma. Proceeding of distribution pattern of Feirana. Phylogenetic relationships of populations of Feirana matched quite with distribution pattern of them, the relationships among clades showed in phylogenetic trees is direct ratio to geographical distance of them; the estimated date of speciation between two species of Feirana was as early as speciation of Paa yunnanesis and Nanara pleski; middle part of Mt. Qinling is the center of speciation of Feirana, combination of mult-events of dispersal and vicariance are probably the mechanism of speciation of Feirana, F. quadrana colonized the mid-Mt. Qinling and then differentiated into two subspecies in southwest direction, ancestral population of F. taihangnicus colonized the mid-Mt. Qinling and then differentiated into two subspecies in northeast direction. On geological history of the distribution of Feirana. According to molecular clock and speciation model of populations of Feirana, some geological events are confirmed, including special rise of Mt. Minshan- Mt. Longmen-western Mt. Qinling, glacial age.

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沙蜥属(Phrynocephalus)的卵胎生类群主要分布在我国青藏高原,包括南疆沙蜥(P. forsythii)、西藏沙蜥(P. theobaldi)、红尾沙蜥(P. erythrurus)、贵德沙蜥(P. putjatia)和青海沙蜥(P. vlangalii)。其卵胎生生殖方式适应了高寒生境,与青藏高原隆升有关。纵观前人的研究,上述几种卵胎生沙蜥的分类、系统发育关系以及生物地理都还存在疑问。本文研究了分布在若尔盖湿地的青海沙蜥红原亚种(P. v hongyuanensis)以及分布在黄河上游其它地区青海沙蜥种组的地理分布格局,并探讨了其形成机制。 青海沙蜥在黄河上游主要分布于若尔盖湿地以及青海湖周边地区。若尔盖湿地青海沙蜥红原亚种的生境由于沼泽的形成被切割成不连续的斑块,通过遗传分析可以推测这种特殊生境对它们遗传结构的影响。其次,贵德沙蜥、青海沙蜥的青海湖周边各居群以及若尔盖湿地居群之间的系统地理格局还未见报道。因此本文以居群为单位,将它们作为一个复合体,通过系统地理研究,可以了解其种群遗传结构,据此分析相关的地质历史事件对其分布的影响。主要结果如下: 1. 若尔盖湿地青海沙蜥红原亚种的种群遗传结构: 共研究了三个地理单元(红原(HY)、辖曼(XM)、玛曲(MQ))的7个采集点的72个个体。所有ND4-tRNALeu序列比对得到785 bp的片断,定义了9种单倍型。结果显示总的核苷酸多样性较低,单倍型多样性较高。分子变异分析(AMOVA)显示3个单元间差异显著(P<0.01),遗传变异主要存在于地理单元间,占62.61%。除MQ单元,XM各居群与HY居群混杂在一起,单倍型网络图没有显示出单倍型和地理位置的对应关系。XM单元单倍型的不配对分布(Mismatch distribution)为明显左移的单峰,且Fu’s Fs test为负值,表明XM单元可能经历了近期种群扩张,有足够的时间积累单倍型的多态性,还不足以大幅提高核苷酸多样性,这是其单倍型多样性较高和核苷酸多样性较低的原因。MQ单元遗传多样性低而与其他单元显著分化,推测这与3万年前黄河在若尔盖玛曲之间贯通有关。近期沼泽的形成对XMb居群的隔离时间短,使得其遗传多样性低但还不足以形成大的遗传差异。无论黄河的贯通还是沼泽的形成其隔离形成的时间都不长,其作用改变了单倍型出现的频率,也出现了一些特有单倍型,但共享单倍型还广泛存在,还不足以使得不同居群之间形成较大的遗传距离。 2. 黄河上游青海沙蜥种组的分布格局与地史过程的关系: 黄河上游青海沙蜥种组包括贵德沙蜥、青海沙蜥指名亚种的青海湖周边各居群、青海沙蜥红原亚种若尔盖湿地居群、以及青海湖以西的部分居群(序列由Genbank下载获得),总计22个居群189个样品。所有ND4-tRNALeu序列比对得到703个位点,定义了39种单倍型。以南疆沙蜥为外群构建的贝叶斯树以及MP法构建的无根树,都分为A、B两大组。其中A包括若尔盖湿地居群以及玛多居群(A1)、青海湖以西的居群和兴海居群(A2)、西藏沙蜥;B包括青海湖以南的居群和天祝居群(B1)、青海湖以东北的居群(B2)。单倍型网络图分别对应了系统发育树上的各支。按照系统发育结果分组进行分子变异分析,得到组间变异占88.63%,各组间差异显著(P=0.000)。种群遗传结构分析得到,A1和B2可能经历了近期的种群扩张,前者扩张时间约为0.105-0.189 Ma B.P.(million years before present),后者为0.057-0.102 Ma B.P.,可能与末次间冰期的气候变暖有关。A2和B1对应的两个地理单元都具有较强的种群遗传结构,较为稳定。 青海沙蜥种组A、B两大支之间遗传距离大,分化明显,分化大约发生在4.29-2.38 Ma B.P.,推测青藏运动的A幕运动后复杂的地形变化可能是它们产生分化的原因。B1和B2分化大约发生在1.73-0.96 Ma B.P.,这与湟水流域构造运动发生的时间相符。在早、中更新世时期,B1支内部各居群可能有交流,中更新世末共和盆地出现的抬升以及河流溯源改道等事件可能是引起这支内部多个单倍型丢失的原因。A1、A2支的分化可能与倒数第三次冰期降临之后气候变冷、阿尼玛卿山的大冰帽有关。 The viviparous group of genus Phrynocephalus is mainly distributed in the Qinghai –Tibetan Plateau, including P. forsythii、P. theobaldi、P. erythrurus、P. putjatia and P. vlangalii. These species are adapted well to the cold clime there, and the origin of this group was the result of a vicariance event associated with the uplifting of the Qinghai -Tibetan Plateau. Although many works have been done, there are still several questions about classification、phylogenetic relationships and the biogeography of this group. The phylogeographic pattern of the P. vlangalii complex on the upper reaches of the Yellow River and the P. v. hongyuanensis in Zoige Wetland were studied in this thesis. On the upper reaches of the Yellow River, P. vlangalii complex are distributed in Zoige Wetland and the southeast and northeast region of Kuku-noor Lake. Because of the forming of the wetland in Zoige, the habitats for sand lizards are divided into many discontinuous ones, and it is necessary to analyze genetic structure in these unique habitats. The phylogeographic patter among P. putjatia、populations of P. vlangalii in the southeast region of Kuku-noor Lake and populations of P. vlangalii in Zoige Wetland hasn’t been studied yet, and the complicated geological events of the Plateau may play an important role in the populations’ diversity and species forming there. So these populations were gathered as a complex, and phylogeographic analysis were used to clarify these doubts. According to the two topics above, this thesis has two parts of results as follows: 1. Three geographic units of P. vlangalii hongyuanensis in Zoige Wetland were defined, and they were Xiaman (XM)、Hongyuan (HY) and Maqu (MQ). 785bp fragments of the mtDNA ND4-tRNAleu were determined from 72 samples and nine haplotypes were identified. As a whole, the nucleotide diversity was low,but the haplotype diversity was high. Analysis of molecular variance (AMOVA) showed that the three units were distinctly different(P<0.01),and 62.61% of the total genetic diversity was attributable to variation among units. There were 3 haplotypes shared among XM and HY,and no geographic clustering was observed except MQ from the TCS network. The results from the mismatch distribution analysis and Fu’s Fs test implied that there might be a recent population expansion in the XM unit, and this may be the reason why XM had a high haplotype diversity but a low nucleotide diversity. We estimate that the MQ and XMb have lower diversities because of some very recent geographic events, such as the formation of the Yellow river’s upriver and the Zoige Wetland. Although they are distinctly different, not enough time has passed for them to have diverged a great genetic distance. 2. 189 samples in 22 populations of P. vlangalii complex were collected, including P. putjatia、populations of P. vlangalii in the southeast and northeast region of Kuku-noor Lake、 populations of P. vlangalii in Zoige Wetland and the data from Genbank. 703bp ND4-tRNALeu sequences identified 39 haplotypes. P. forsythii was selected as outgroup, and both the Bayesian tree and the MP unrooted tree were divided into two groups(A、B). A included populations in Zoige Wetland and Xinghai(A1)、populations in the west of Kuku-noor Lake(A2)、P. theobaldi, and B included populations in the southeast of Kuku-noor Lake and Tianzhu(B1)、populations in the northeast of Kuku-noor Lake(B2). The haplotype network agreed with these groups. AMOVA showed that these five groups were distinctly different(P<0.01), and 88.63% of the total genetic diversity was attributable to variation among groups. There might be recent population expansion in A1 and A2, which corresponded to the dry climate of the last interglacial period. The expansion times were 0.189-0.105 Ma B.P. and 0.102-0.057 Ma B.P., respectively. A2 and B1 had strong genetic structure. The large genetic distance between A and B showed that they had been separated from each other for a long time(about 4.29-2.38 Ma B.P.), and it corresponded to the A phase of Qingzang Movement. The diversity between B1 and B2 at 1.73-0.96 Ma B.P. may be caused by the geological event in Huangshui valley. In early Pleistocene, populations in B1 may have gene flow because of geographic linkage, and later the uplift of the Plateau and the change of river route there made a few haplotypes lost. A1 and A2 were divided into two parts by A’nyemaqen Mountains at 0.66-0.37 Ma B.P., which maybe corresponded to glaciations at about 0.7 Ma B.P.