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1.
ABUNDANCE AND PRODUCTION OF BRANCHIURA SOWERBYI (OLIGOCHAETA: TUBIFICIDAE) IN TWO TYPICAL SHALLOW LAKES (HUBEI, CHINA) 总被引:1,自引:0,他引:1
INTRODUCTIONBranchiurasowerbyi,acosmopolitantubificid,isapredominantzoobenthosinmanyshallowlakesinChina(Liang,1979).In1984,theproductionratesofthespecieswerefirstestimatedinDonghuLake,Wuhan(Liang,1984).Afterthat,nodataonproductionofthiswormorotherzoobenthoswerep… 相似文献
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INTRODUCTIONBellamyaaeruginosaisagastropodspeciesbelongingtoViviparidae .Beingadetritivore,thespeciesiscommonlypresentinmostfreshwaterbodies.Inbiomass,thisanimalisprobablythefirstdominantspeciesofmacrozoobenthos,soitplaysanimportantroleinmaterialcircula… 相似文献
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ABUNDANCE AND PRODUCTION OF LIMNODRILUS HOFFMEISTERI (OLIGOCHAETA : TUBIFICIDAE) IN ALGAE-DOMINATED LAKE HOUHU (WUHAN, CHINA) 总被引:1,自引:0,他引:1
April, 1996 to March, 1997 studies on the abundance and secondary production of Limnodrilus hoffmeisteri in an algae-dominated lake showed that the worm density and biomass peaked in December at 152 ind/m^2 and 0.087 g/m^2 , respectively. The secondary production of the animal was 0.294g/m^2 fresh wt/a. The turnover rate (P/B ratio) was 11.4. 相似文献
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ImODareNThelast3Oycars'~tilicproductinnofsalts,andnawh,andexpIorationofsaltlakes,haveyboedmuCinfonnationonQarhanInke.Thereisliteraturedetailingthelakebpaleo-dhate,paboenvbonment,paboerelogy,evolution,etC-since5OkaB.P.(ZhengPenShinCtal.,l993,ChenKereoetal.,l986;HuangQiCtal.,l98l),butfewonthebefore5OkaB-P-eventS.CoreCk6thattheFirsttheloghalExplorationTeamoftheQinghaibologicalBu-rmudrilledat9lOmdePthinQarhanLakeyallasetofcontinuouslylacustrinetali-rnentdataveryvaluableforstudyofpabo… 相似文献
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INTRODUCTIONMacrozoobenthos ,amajorgroupofaquaticfauna ,playsanimportantroleinthematerialcycleandenergyflowinawaterecosystem .Inrecentdecades ,interestinthebioenergeticsofthisgrouphasgrownrapidly .Aspectsofthebioenergeticsofmanybenthicfreshwaterspecieshavebeenpub lished .Owingtodifficultyinsamplecollectionandspecimenprocessing ,studiesofthebenthiccom munityhavereceivedlessattention .Withfisherydevelopmentandthelakeeutrophicationproblem ,investigationsontheecologicalfunctionofthelakecommun… 相似文献
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According to loess and palaeosol climatic record, field observation, analysis data and 14C dating, we discuss the climatic changes and the water level fluctuations of Qinghai Lake. It is pointed out that there were four relatively warm and moist stages in Qinghai Lake basin during the Holocene. They formed in the periods from 10,300 yr.B.P. to 8,500 yr.B.P., 7,000 yr.B.P. to 3,500 yr.B.P., 2,800 yr.B.P. to 2,000 yr.B.P. and from 1,300 yr.B.P. up to now. The climate in the Holocene optimum period, from 7,000 yr.B.P. to 3,500 yr.B.P., was much warmer and moister than that today. Polypodium plant grew luxuriantly around Qinghai Lake. The annual temperature was 2.5℃ higher than that today, but there was no forest at Qinghai Lake shore. It is found that there was a good relationship between precipitation and water level fluctuation. In warm and moist period water level was high and in the cold and dry period it was low in the Holocene. There were four high water level periods for Qinghai Lake in the Holocen 相似文献
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The energy budget ofBellamya earuginosa in a shallow algal lake, Houhu Lake (Wuhan, China) was investigated by the measurement of flesh production (32.8 kJ/(m2·a)), egestion (337.7 kJ/(m2·a)), metabolism (246.7 kJ/(m2·a)), and estimation of excretion (21.4kJ/(m2·a)). The net growth efficiency of the species is about 10.9%, which accords with the generally reported value for gastropods.
In addition, the relationships between starvation respiration (R, mgO2/(Ind·d)), body weight (Wd, mg in dry wt) and temperature (T, °C) were also determined. The regression equationR=0.044Wd
0.537
e
0.061T
was obtained by the least square method, The measured SDA of the species is 26.51% of its gross metabolism.
Project No. 3960019 and 39430101 supported by NSFC and also a granted for the East Lake Ecological Experimental Station, CAS,
Wuhan. 相似文献
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THEHOLOCENESEDIMENTALCHARACTERISTICANDPALEOCLIMATICEVOLUTIONOFEBINURLAKE,XINJIANG吴敬禄,王苏民,吴艳宏THEHOLOCENESEDIMENTALCHARACTERIST... 相似文献
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1INTRODUCTIONGrain production has always been top-priority issue con-cerned by government and people (MA etal., 2002). Af-ter China put household contract responsibility system in force, its domestic issue of grain was basically settled in the mid 1980s (MA and XU, 1999). However, in the days when idea of sustainable development is broadly accepted, efficiency and sustainability of grain produc-tion are now in question, which have prompted interest in reviewing grain production patterns… 相似文献
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分析了运城盐湖盐类矿床的地质特征,指出其剖面上的周期性、平面上的迁移性,演化过程的波浪性,构造环境的峰谷性,成矿物质的多源性,据此提出盆-岭式成盐新模式。 相似文献
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陈家其 《中国地理科学(英文版)》1994,(2)
THE APPLICABILITY OF RESEARCH ON FLOOD-DROUGHT TENDENCY-AN ANALYSIS ON DISASTROUS FLOOD OF TAIHU LAKE BASININ JUNE-JULY,1991 ... 相似文献
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Jiaozhou Bay data collected from May 1991 to February 1994, in 12 seasonal investigations, and provided the authors by the Ecological Station of Jiaozhou B ay, were analyzed to determine the spatiotemporal variations in temperature, light, nutrients (NO-3-N, NO-2-N, NH+4-N, SiO2-3-Si, PO3-4-P), phytoplankton, and primary production in Jiaozhou Bay. The results indicated that only silicate correlated well in time and space with, and had important effects on, the characteristics, dynamic cycles and trends of, primary production in Jiaozhou Bay. The authors developed a corresponding dynamic model of primary production and silicate and water temperature. Eq.(1) of the model shows that the primary production variation is controlled by the nutrient Si and affected by water temp erature; that the main factor controlling the primary production is Si; that water temper ature affects the composition of the structure of phytoplankton assemblage; that the different populations of the phytoplankton assemblage occupy different ecologica l niches for C, the apparent ratio of conversion of silicate in seawater into phytoplankton biomas and D, the coefficient of water temperature's effect on phytoplankton biomass. The authors researched the silicon source of Jiaozhou Bay , the biogeochemical sediment process of the silicon, the phytoplankton predominan t species and the phytoplankton structure. The authors considered silicate a limit ing factor of primary production in Jiaozhou Bay, whose decreasing concentration of silicate from terrestrial source is supposedly due to dilution by current and up take by phytoplankton; quantified the silicate assimilated by phytoplankton, the intrins ic ratio of conversion of silicon into phytoplankton biomass, the proportion of silicate uptaken by phytoplankton and diluted by current; and found that the primary production of the phytoplankton is determined by the quantity of the silicate assimilated by them. The phenomenon of apparently high plant-nutrient concentrations but low phytoplankton biomass in some waters is reasonably explained in this paper. 相似文献
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本文分析了早寒武世单板类Yerhelcionella在世界上几个国家和地区的产出层位及形态特征,认为中国河南的Y.chinensis产出层位最低,形态结构原始,是世界上发现的最古老的Yochelcionella,提出Y.chinensis在河南前次出现,并迁移到澳大利亚Flinders地区生存。西伯利亚的Y.stylifera和北美的Y.americana也可能与河南的Y.chinensis有一定联系。澳大利亚新南威尔士所产Y.cyrano.Y.daleki.Y.ostentata三个高级种与Y.chinensis有着密切的演化关系。此外对Yochelcionella的起源与进化提出见解。 相似文献
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Abundance and production ofBranchiura sowerbyi (Oligochaeta: Tubificidae) in two typical shallow lakes (Hubei, China) 总被引:1,自引:0,他引:1
An April 1996 to March 1997 comparative study on the abundance and secondary production ofBranchiura sowerbyi Beddard, 1892 in two typical shallow lakes showed that in Houhu, an algae-dominated lake, the worm density (68 ind·m−2) peaked in July, biomass (1.930 g·m−2) peaked in June, while in Biandantang, a macrophyte-dominated lake, standing stock (density: 60 ind·m−2; biomass: 1.019 g·m−2 in wet weight) peaked in December. Secondary production of the animal in Houhu Lake was 3.413 g wet wt m−2 a−1, a little more than that (2.675 g wet wt m−2 a−1) in Biandantang Lake. Their turnover rates (P/B ratios) were 4.0 and 5.0, respectively.
Project (39600019 and 39430101) supported by NSFC. 相似文献
17.
河南宝玉石矿床分布 ,根据成矿特征 ,可划分宝石与玉石两类 :宝石类有金刚石、欧泊、紫晶 ;玉石类有独山玉、绿松石、虎睛石、密玉和玛瑙等。并提出了河南宝玉石找矿方向。 相似文献
18.
奥斯特 《地球科学与环境学报》1994,(2)
现代气候条件下,秦岭中部(33°58'N/107°45'E)3400m以上存在一具有冰缘地貌特征和冰川作用的高山草甸环境。冰冻泥流斜坡、千奇百怪的砾石和无植被覆盖的冰冻泥流、各种形式的冰阶和冰坎以及石环和石多边形等,组成了目前冰缘环境的地貌特征。在3400m以上发现了高山永久性冻土。通过冰蚀漏斗和冰融四地,证明在2900~3300m之间秦岭中部存在一晚更新世时期的冰融地区。根据古冰斗和冰碛的地貌形态调查及形态测量分析,可得出如下假设:在拔仙台、酉跑马梁附近当时存在一个晚更新世时期的小冰盖,冰盖边缘派生了5个小的外流冰舌。在拔仙台附近的沟谷里一些冰碛地貌存在于2500m以上。笔者根据调查结果,划分了两个晚更新世时期的冰期,即太白Ⅰ和太白Ⅱ冰期。在这两个冰期之间,估计存在一间冰期。晚更新世3250~3300m的冰川雪线高度是根据太白Ⅰ冰期冰碛位置得出的。同目前所推测的现代冰川雪线位置相比,形成的雪线下降大约在1000~1300m之间,没有观察到全新世冰川遗迹。 相似文献
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豫鄂湘桂4省(区)共有49个产(富)铀层组.主要有上震工统一下寒武纯、中泥盒统,下二叠统及上由叠统.其时空分布与地壳演化有关.受特定的构造捷回和大地构造单元控制.岩性为一定地质时期形成的海相碳硅泥岩建造和河流一滨湖三角洲相砂岩建造.富铀层往往是极重要的铀源层及良好的储铀层.产(富)铀层的岩性序列组合,岩石的化学和物理性质及构造一岩浆作用的叠加,严格控制着铀矿化的形成和富集. 相似文献
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广西中三叠统浊流流向及坡向 总被引:1,自引:0,他引:1
通过对广西中三叠统浊积岩系中溢堤流沉积的识别,结合同一鲍马层序Tc段斜层理倾向与其底部槽模走向不一致的分析,以及横向冲刷模、U形障碍冲刷痕等冲蚀构造、大型滑动模等压刻构造的认识,筛选出宽阔水道充填沉积、扇状体及分支水道沉积中底模构造的指向数据,来指示浊流主体流向,并区分出溢堤流流向。从而确定了本区中三叠世时的浊流主体流向为NW向,平均为300°。根据滑塌沉积中滑塌包卷层轴面、滑塌面的测定,确定凤山县金牙处的古坡向平均为322°,与浊流主体流向基本一致。还认为中三叠世时右江盆地沉积物源来自桂东和桂东南蚀源区,海水由其南的越南境内进入。 相似文献