Plant Diversity on the North of East Lake Luoyan Scenic Area in Wuhan Municipality

The research was conducted as per biocenology normal sampling method in the north of East Lake Luoyan Scenic Area and the results showed that of 14 sample plots, there are 62 species in 56 genera in the families of 38, including 32 arbor species, 22 shrub species and 8 herbaceous species. Cinnamomum septentrionale and Cynodondactylon（Linn.） Pers. appeared the most frequently of 64.3%.Margalef＇s index, Shannon-wiener index and Simpson index from high to low were all arbor layershrub layerherbaceous layer, of which arbor layer in green space D kept the highest in terms of Margalef＇s index, and herbaceous layer in the space was the lowest. Besides, herbaceous layers maintained the highest in Pielou＇s index and shrub layer the lowest.

Relationship between community type of wetland plants and site elevation on sandbars of the East Dongting Lake,China

Plant communities on sandbars were important, and restoration of degraded wetland were significant to biological conservation in the East Dongting Lake region. In this study, typical wetland community types on sandbars and their site elevation were surveyed to explore relationship between community distribution and site elevation. Results show that eight major communities in this region were wetland communities dominated by Juncus effusus, Carex brevicuspis, Polygonum hydropiper, Salix triandra, Oenanthe Javanica, Phalaris arundinacea, Miscanthus sacchariflorus and Phragmites communis respectively. These communities had obvious constructive species and companion species, while site elevation could affect community composition and their species diversity. On sandbars in the East Dongting Lake, vegetation was largely composed of hygrophytes companied with a few mesophytes. The higher the site elevation was, the nearer the site was to the water, and the lower community diversity became. Except soil humidity and site elevation, growth period of plants after inundation could also affect species richness in the communities.

Viral Metagenomics Analysis of Planktonic Viruses in East Lake,Wuhan,China

East Lake(Lake Donghu),located in Wuhan,China,is a typical city freshwater lake that has been experiencing eutrophic conditions and algal blooming during recent years.Marine and fresh water are considered to contain a large number of viruses.However,little is known about their genetic diversity because of the limited techniques for culturing viruses.In this study,we conducted a viral metagenomic analysis using a high-throughput sequencing technique with samples collected from East Lake in Spring,Summer,Autumn,and Winter.The libraries from four samples each generated 234,669,71,837,12,820,and 34,236 contigs(>90 bp each),respectively.The genetic structure of the viral community revealed a high genetic diversity covering 23 viral families,with the majority of contigs homologous to DNA viruses,including members of Myoviridae,Podoviridae,Siphoviridae,Phycodnaviridae,and Microviridae,which infect bacteria or algae,and members of Circoviridae,which infect invertebrates and vertebrates.The highest viral genetic diversity occurred in samples collected in August,then December and June,and the least diversity in March.Most contigs have low-sequence identities with known viruses.PCR detection targeting the conserved sequences of genes(g20,psbA,psbD,and DNApol)of cyanophages further confirmed that there are novel cyanophages in the East Lake.Our viral metagenomic data provide the first preliminary understanding of the virome in one freshwater lake in China and would be helpful for novel virus discovery and the control of algal blooming in the future.

Role of lithology, weathering and precipitation on water chemistry of lakes from Larsemann Hills and Schirmacher Oasis of East Antarctica

Schirmacher Oasis and Larsemann Hills areas represent two different periglacial environments of East Antarctica. Schirmacher Oasis is characterized by a vast stretch of ice-shelf in the north and East Antarctic Ice Sheet(EAIS) to its south. Whereas, in Larsemann Hills area the northern and north-western boundary is coastal area and EAIS in the southern part,exhibiting polar lowland between the marine and continental glacial ecosystems. Physico-chemical parameters of water samples from different lakes of both of these two distinct locations are quite contrasting and have indicated influence of lithology, weathering, evaporation and precipitation. The lake water chemistry in Larsemann Hills area is mainly governed by the lithology of the area while Schirmacher lakes exhibit influence of precipitation and rock composition. All major ions of lake waters indicate balanced ionic concentrations. The atmospheric precipitation has significantly modified the ionic distributions in the lakes and channels. Carbonation is the main proton supplying geochemical reactions involved in the rock weathering and this is an important mechanism which controls the hydrochemistry. The lake water hydrochemistry differs widely not only between two distant periglacial zones but also within a short distance of a single periglacial entity, indicating influence of territorial climate over hydrochemistry.

Phylogenetic and Molecular Analysis of an H7N7 Avian Influenza Virus Isolated in East Dongting Lake in 2012

Objective In March 2012, an H7N7 subtype avian influenza virus （AIV） named A/wild goose/Dongting/PC0360/2022 （H7N7） （DT/PC0360） was recovered from a wild goose in East Dongting Lake. We performed whole-genome sequencing of the isolate, and analyzed the phylogenetic and molecular characterization. Methods RNA was extracted from environment samples （including fecal samples from wild bird or domestic ducks, and water samples） for detecting the presence of Influenza A Virus targeting Matrix gene, using realtime RT-PCR assay. The positive samples were performed virus isolation with embryonated eggs. The subtype of the isolates were identified by RT-PCR assay with the HI-HI6 and N1-N9 primer set. The whole-genome sequencing of isolates were performed. Phylogenetic and molecular characterizations of the eight genes of the isolates were analyzed. Results Our results suggested that all the eight gene segments of DT/PC0360 belonged to the Eurasian gene pool, and the HA gene were belonged to distinct sublineage with H7N9 AIV which caused outbreaks in China's Mainland in 2013. The hemagglutinin cleavage site of HA of DT/PC0360 showed characterization of low pathogenic avian influenza virus. Conclusion Strengthening the surveillance of AlVs of wild waterfowl and poultry in this region is vita for our knowledge of the ecology and mechanism of transmission to prevent an influenza pandemic.

Concentrations and contamination trends of heavy metals in the sediment cores of Taihu Lake,East China,and their relationship with historical eutrophication

To assess the contamination trends and potential bio-availability of sediment-bound heavy metals,concentrations of heavy metals in acid-leaching fraction and in bulk sediments from the two typical bays(the Meiliang Bay and Xuhu Bay) of the Taihu Lake,East China,were studied.Pb and Zn showed elevated concentrations in the sediments from both areas,although sedimentation history and degree of pollution are different between the two bays.In the Meiliang Bay,both Pb and Zn pollutions started in the late 1970's,the same time as the beginning of eutrophication of the lake,while the in the Xuhu Bay the metal contamination started since recent 10 years.The concentrations of acid-leachable Pb in the sediments from the Meiliang Bay are correlated with the historical eutrophication process.Before the eutrophication and heavy metal pollution,the chemical properties of the lake sediments were the same as the source compositions of the Xiashu loess.Both Pb and Zn in the sediments mainly occur in leachable forms by nitric or hydrochloric acid,whilst most of Cu is in residual fraction.The results indicate that both Pb and Zn may have higher mobility and bioavailability in water and biology than Cu.

Preparation and Properties of Ceramic Facing Brick from East-lake Sediment

In order to utilize solid wastes, ceramic facing brick was made form East-lake sediment and some additives. The strength and freeze-thaw resistance of the samples were tested, and the crystal phases and microstructures were studied by XRD and SEM. The results indicate that the samples have a wide firing temperature range. The main crystal phases are CaA12SizOs, a-Al203, Fe203, which distribute uniformly in the samples. The sample have the best properties in the series ＇Ca-A1-Si＇, and water absorption （Wa）, porosity （Pa）, bulk density （D）, bending strength and compressive strength are 7.24%, 15.82%, 2.19 g.cm＂3, 45.57 MPa and 56.81 MPa respectively, when the addition amount of East-lake sediment is 80% and the firing temperature is 1 100 ~C. In the series ＇K-A1-Si＇, the sample with the best properties was obtained when addition amount of East-lake sediment was 70% and firing temperature was 1 060 ~C. The water absorption, porosity, bulk density, bending strength and compressive strength are 7.62%, 16.37%, 2.15 g ~ cm＂3, 39.26 MPa, and 50.81 MPa respectively. They all come up to the national standardization, and meet the needs of manufacturing production.

Ontogenetic changes in isotopic signatures of an omnivorous fish Cultrichthys erythropterus in East Lake Taihu,China

The relationship between body size and stable isotopic signatures of the omnivorous Redfin Culter(C ultrichthys erythropterus),commonly found in East Lake Taihu,was investigated. Previous analyses of C. erythropterus stomach contents have shown that this species undergoes a diet switch from being predominantly zooplanktivorous to piscivorous during its life history. This was confirmed by stable carbon isotopic signature(δ 13 C) in this study,in which δ 13 C was positively correlated with both standard length and weight. The importance of littoral-benthic resources in supporting C. erythropterus during its lifespan was also demonstrated using a two-source mixing model,the results of which showed a significant increasing trend in the contribution of littoral-benthic energy. However,the stable nitrogen isotopic signature(δ 15N) exhibited an unusual pattern compared with previous studies. The δ 15 N of C. erythropterus showed no relationship with body size,even though dietary changes were observed. This indicated that δ 15 N alone cannot fully reflect a diet shift in a species and possible variability in isotopic signatures over its life history. This should be considered when using stable isotopic signatures to investigate intra-specific variations and the timing of life-history events,such as estimating the trophic positions of fish species.

Evolution of Industrial Competitiveness Based on Evaluation of Urban Competitiveness of Dongguan City:A Case Study of Songshan Lake High-tech Zone

Based on the theoretical system of urban competitiveness,the evaluation model of urban competitiveness from the perspective of competition and cooperation was established.According to the significance index and explanatory index,the urban competitiveness was divided into urban comprehensive competitiveness(UC),urban internal node competitiveness(NC)and external competitiveness of urban network(EC).The scores and rankings of UC,NC and EC in 2006,2010 and 2015 were obtained by conducting the comprehensive evaluation of the urban competitiveness of Dongguan City with integrated usage of the principal component analysis and Technique for Order Preference by Similarity to an Ideal Solution and the data of other 20 cities in Guangdong province,Hong Kong and Macao.The research showed that the competitiveness of Dongguan City has been greatly improved during the decade of 2006–2015,and the regional cities in Guangdong Province had significant differences,which are reflected in the two dimensions of urban internal node competitiveness(NC)and external competitiveness of urban network(EC).Based on this,this study further analyzed Dongguan’s urban competitiveness from two dimensions of NC and EC,and took Dongguan Songshan Lake High-tech Zone as an example to study how to promote Dongguan’s urban competitiveness from the industrial level.

Holocene Vegetation and Climate Changes in the Huangqihai Lake Region, Inner Mongolia

A consensus on Holocene climate variability at the modern northern fringe of the East Asian summer monsoon(EASM) region remains elusive. Here, we present a pollen-based reconstruction of vegetation history and associated climate variations of a sediment core from Huangqihai Lake, central Inner Mongolia. During 10.7 to 8.8 cal kaBP, typical steppe with small patches of forest dominated the lake area, suggesting a moderately wet climate, followed by ameliorating climatic conditions until 8.0 cal kaBP as deduced by the expansion of forest. Typical steppe recovered the lake area between 8.0 and 7.2 cal kaBP, reflecting a deterioration of climatic conditions;in combination with other proxy records in the study region, we noticed that severe aridity was prevailed in the lake area between 8.0 and 7.6 cal kaBP. During 7.2 to 3.2 cal kaBP, abundant tree pollen indicated dominance of forest-steppe around the lake, marking regionally wet conditions. A notable absence of broadleaved trees after 5.2 cal kaBP reveals a slight drying trend, and climate deterioration from 4.5 to 4.1 cal kaBP might be linked to the 4.2 ka event. After 3.2 cal kaBP, a transition to steppe was associated with dry conditions in the region. Based on our pollen record and prior paleoclimatic reconstructions in the Huangqihai Lake region, there was a generally-accepted, stepwise shift to a wet climate during the early Holocene, an overall humid climate from 7.2 to 3.2 cal kaBP, and then severe drought for the rest of the Holocene. Moreover, regional comparisons among pollen records derived from lakes situated in the temperate steppe region suggested a roughly synchronous pattern of vegetation and climate changes during the Holocene and demonstrated an intensified EASM during the middle Holocene.

DIAGNOSTIC ANALYSIS OF PERSISTENT DROUGHT/FLOOD EVENTS IN SUMMER OVER THE TWO-LAKE REGION OF CHINA

Based on the daily regional mean rainfall,the Z-index method is used to identify persistent flood and drought events lasting for at least 10 days over a region where Dongting Lake and Poyang Lake sit(referred to as the"two-lake region"hereafter).The National Centers for Environmental Prediction(NCEP)reanalysis data are then utilized to perform a preliminary diagnostic analysis on these events.The results indicate that the composite standardized geopotential height at 500 hPa presents two different meridional wave trains from north to south over the East Asian-Pacific region,i.e.,a"-+-"pattern for the droughts and a"+-+"pattern for the floods,respectively.The developing,maintaining and decaying phases in the drought and flood events are closely related to the intensity and location of a subtropical high and an extra-tropical blocking high.It is shown that the East Asian summer monsoon is strong(weak)with the occurrence of persistent drought(flood)events.Droughts(floods)are accompanied by a weak(strong)tropical convergent system and a strong(weak)subtropical convergent system.Furthermore,the persistent drought(flood)events are associated with a divergence(convergence)of vertically integrated water vapor flux.In the vertical profile of water vapor flux,divergence(convergence)in the mid-and lower-levels and convergence(divergence)in the higher levels are evident in the droughts(floods).Both the divergence in the droughts and the convergence in floods are strongest at 850 hPa.

Aeolian component records in lacustrine sediments and its atmospheric circulation significance for evolution of Qarhan salt lake,NE Qinghai-Tibetan Plateau

1 Introduction The Qarhan Playa of Qaidam Basin is located at the northeastern QinghaiTibetan Plateau(QTP),in which thick lacustrine and evaporate sediments deposited since the late Pleistocene(Chen et al.,1985,1986).As surrounded by capacious Gobi and yardang fields and suffered strong westerly-northwesterly wind,abundant aeolian materials were trapped in these sediment sequences in the

A Discussion of Some Problems Concerning the Tosonhu Lake M_S7.5 Earthquake in 1937

The East Kuulun active fault zone, which lies in the valley of the Kuulun Mountains above an elevation of 4,000 meters, is an important active fault zone in the Northeast Qinghai-Xizang （Tibet） Plateau. The 1937, the Tosonhu lake Ms7. 5 earthquake occurred in the eastern segment of the East Kuulun active fault zone. Four field investigations were launched on this seism in 1963, 1971, 1980, and between 1986 and 1990. However, due to different extents of the investigations, four different conclusions have been gained. Concerning the length aspect of the surface rupture zone of this earthquake, the unanimous consensus is that its eastern end lies in the west side of the main Ridge of the A ＇nyemaqen Mountains, but opinions about the western end and the location of the macro-epicenter are different. Based on investigation and comprehensive study, a series of scientific problems like geometric and kinetic characteristics, the length of the rupture zone, the maximum sinistral horizontal displacement and the macroepicenter were re-evaluated. We believe that the total length of this earthquake＇s surface deformation zone is at least 240km; the western end of the zone is at the west of Wnsuwuwoguole; the maximum sinistral horizontal displacement is 8m to the west of Baerhalasha gully on the east side of Sanchakou; the maximum vertical displacement is 3.5m in the south of Sanchakou and the macro-epicenter is in Sanchakou.

东洞庭湖洪水前后典型湿地植物化学计量特征动态变化

洪水对湿地土壤-植被系统养分循环有重要影响。本研究以东洞庭湖湿地典型植物短尖苔草(Carex brevicuspis)和南荻(Triarrhena lutarioriparia)为研究对象,于2018年洪水期前后(5月、10月)测定短尖苔草和南荻生长特征、生态化学计量特征及土壤理化性质,并对化学计量学特征与环境特征的相关性进行了分析。结果表明:南荻植株的生物量和密度洪水前显著高于洪水后,短尖苔草生物量和密度洪水前后都没有显著差异;短尖苔草、南荻叶片有机碳(SOC)洪水后显著高于洪水前;短尖苔草叶片全氮(TN)洪水前显著低于洪水后;南荻叶片TN、全磷(TP)洪水前显著高于洪水后;短尖苔草叶片TP洪水前后没有显著差异。短尖苔草叶片C∶N、C∶P、N∶P洪水前后均无显著差异,南荻叶片C∶N、C∶P洪水前显著低于洪水后,但N∶P洪水前后无显著差异。东洞庭湖短尖苔草、南荻叶片N∶P<14,东洞庭湖短尖苔草、南荻生长更多的受N限制,洪水前后都与土壤N、P含量无显著相关性。本研究结果对阐明洪水对湿地植物化学计量特征的影响有重要意义。

东昆仑库木库里盆地典型湖泊水量蒸发损失估算

湖泊水量蒸发损失估算对于应对干旱区水资源短缺及湖泊生态环境保护具有重要意义。计算分析了过去20 a东昆仑库木库里盆地典型湖泊实际蒸散发(ET)的时空变化特征,并基于经验公式估算了湖泊蒸发损失水量,同时利用随机森林模型,识别了影响湖泊水量蒸发损失变化的潜在因子。研究发现:(1)2001-2020年东昆仑库木库里盆地的阿牙克库木湖、阿其克库勒湖和鲸鱼湖的年ET整体呈现先增加后减少又缓慢增加的波动下降趋势,波峰和波谷均分别出现在2004年和2012年左右,空间上表现为ET整体下降而湖泊边缘呈上升趋势。(2)3个典型湖泊的ET在年内呈倒U形变化,其中阿牙克库木湖的ET在6月达到峰值,其他2个湖泊的ET均在7月达到峰值。(3)2001-2020年3个典型湖泊的蒸发水量均呈不显著的增加趋势,其中阿牙克库木湖的蒸发水量最高,平均约为10.33×10^(8)m^(3)·a^(-1),阿其克库勒湖的蒸发水量次之(4.54×10^(8)m^(3)·a^(-1)),鲸鱼湖的蒸发水量最低(3.33×10^(8)m^(3)·a^(-1))。(4)结合随机森林模型分析显示,湖泊面积是影响湖泊蒸发水量的重要因素,经向风速、最高气温和降水的增加等因素也是驱动蒸发变化的重要原因,累计贡献率超过45%。

作为纪念的空间及其生成——以苏轼东湖故事为中心视域

苏轼东湖纪念空间有三类景观组成:其一,苏轼在凤翔入仕期间率人兴建的建筑物;其二,苏轼所建但居于东湖之外,后来被人迁入东湖的建筑物;其三,后人在东湖之中新建的纪念性建筑物。围绕苏轼和凤翔东湖,每一处景观都有一段流传于世的故事或传说,成为人们缅怀和纪念苏轼时所无法遗忘的一种文化景观。苏轼东湖纪念空间的形成离不开苏轼和凤翔东湖,更离不开基于某种理想而来的纪念之情,后者才是构成这一纪念空间的关键要素。

基于大型底栖动物完整性指数与综合生物指数的水生态评价

针对不同流域部分生物指数评价标准并不统一的问题,利用熵权法构建综合生物指数(CBI)统一模糊评价标准,同时计算底栖动物完整性指数进行评价结果验证.以2021年秋季和2022年春季东洞庭湖10个监测点的数据为基础,通过对25个候选参数逐步筛选,选出M3(软体动物分类单元数)、M9(耐污类群相对丰度)、M13(BI指数)和M22(Shannon-Wiener指数)4个秋季核心参数以及M6(摇蚊个体相对丰度)、M13、M16(BPI指数)和M24(Margalef指数)4个春季核心参数,采用比值法统一量纲后累加计算底栖动物完整性指数,再对BPI、FBI、Shannon-Wiener、BMWP指数客观定权后计算CBI指数划分出5个状态进行对比,结果表明:B-IBI指数和CBI指数均得出靠近出湖河道点位较为健康,湖体点位多为一般和较差,整体秋季健康状况略好于春季,六门闸附近为极差状态,可能是因为该区域是东洞庭湖的闸口之一,常年关闭导致水体流动性较差,开闸放水后沉积物中的淤泥会释放污染物使得湖区总氮超标,进而影响了大型底栖动物的完整性.CBI指数与B-IBI指数以及COD_(Mn)、TLI(∑)指数等相关分析结果良好,表明利用综合生物指数和底栖动物完整性指数结合能为东洞庭湖的水生态健康评价提供参考.

典型挺水植物应用于湿地生态修复工程污染净化效应差异性研究

以洱海流域北部上游东湖片区库塘湿地中水生植物为研究对象,选取5种主要水生植物,寻求净化湿地水质的最佳植物组合。结果表明:东湖片区库塘湿地水体总磷、总氮、氨氮、化学需氧量分别为0.09~0.23、0.80~3.28、0.18~0.89、12.00~37.00 mg/L,总体符合《地表水环境质量标准》(GB 3838—2002)中Ⅳ类要求;综合比较发现,植物组合群落生物量和碳氮磷累积效应优于单一植物;植物组合对水体碳氮磷具有一定的吸收净化作用。

东洞庭湖表层沉积物中抗生素及抗性基因的时空分异特征

为研究东洞庭湖抗生素及抗性基因(Antibiotic Resistance Genes,ARGs)的时空分异特征,采集了东洞庭湖流域丰水期和枯水期的沉积物样品,使用超高效液相色谱-串联质谱法和实时荧光定量PCR技术研究了4类12种抗生素和8种相应抗性基因。结果表明:沉积物中抗生素浓度水平处于ng·g^(-1)级别,枯水期4类12种抗生素的检出率和浓度水平均高于丰水期。丰水期沉积物浓度范围为ND(未检出)~176.94 ng·g^(-1),平均浓度为9.75 ng·g^(-1);枯水期浓度范围为ND~101.34 ng·g^(-1),平均浓度为10.88 ng·g^(-1);磺胺类和喹诺酮类抗生素是东洞庭湖主要的抗生素。丰水期沉积物样品中共检出8种ARGs,绝对丰度范围在ND~1.03×10^(7)copies·g^(-1);枯水期绝对丰度范围为9.93×10^(2)~6.32×10^(9)copies·g^(-1)。从空间上看,下游ARGs总丰度高于上游。沉积物中抗生素与ARGs具有一定的相关性,并且在枯水期表现出更好的正相关性。研究表明,东洞庭湖表层沉积物中抗生素及抗性基因的浓度随时间和空间的变化有较明显的差异,在枯水期和靠近水产养殖的区域污染水平更高。