Phytoplanktonic desmids community in Donghu Lake, Wuhan, China

For compilation and comparison of desmids flora, the authors restudied the species composition, cell density and biomass of phytoplankton desmids collected at six stations in Donghu Lake at intervals of three months monitored from March of 1956 to February of 1957. A total of 122 taxa belonging to 16 genera were identified from qualitative and quantitative samples. Species of Cosmarium were the most popular ones occupy- ing about 41 % of the total species. Based on the observations, the annual mean values of the cell density and biomass were 132.11×102 cells/L and 0.09 mg/L. Cosmarium, Staurastrum, Staurodesmus and Closterium dominated and contributed more than 70 % of the total cell density and biomass at six stations in four seasons. The maximum species number, cell density and biomass in autumn revealed that the highest variety (64 taxa, 1296×102 cells/L and 0.889 mg/L respectively) occurred at Station 3 located in the southern part of Donghu Lake. From then on to the mid 1990s the desmids community decreased sharply in Donghu Lake, resulted clearly from eutrophication in the lake.

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.

Relationships between testate amoeba communities and water quality in Lake Donghu, a large alkaline lake in Wuhan, China

The middle Yangtze Reach is one of the most developed regions of China. As a result, most lakes in this area have suffered from eutrophication and serious environmental pollution during recent decades. The aquatic biodiversity in the lakes of the area is thus currently under significant threat from continuous human activities. Testate amoebae （TA） are benthic （rarely planktonic） microorganisms characterized by an agglutinated or autogenous shell. Owing to their high abundance, preservation potential in lacustrine sediments, and distinct response to environmental stress, they are increasingly used as indicators for monitoring water quality and reconstructing palaeoenvironmental changes. However this approach has not yet been developed in China. This study presents an initial assessment of benthic TA assemblages in eight lakes of Lake Donghu in the region of Wuhan, China. Testate amoeba community structure was most strongly correlated to water pH. In more alkaline conditions, communities were dominated by Centropyxis aculeata, Difflugia oblonga, Pontigulasia compressa, Pon. elisa and Lesquereusia modesta. These results are consistent with previous studies and show that TA could be useful for reconstructing past water pH fluctuations in China. To achieve this, the next step will be to expand the database and build transfer function models.

A GIS-based Spatial Analysis of Housing Price and Road Density in Proximity to Urban Lakes in Wuhan City, China

As one of the essential urban open spaces, lakes usually contribute immensely to the quality of residents′ daily lives. Different from hedonic approach employed in existing researches on urban open spaces in China, this paper integrates housing price surface with road density to analyze the spatial characteristics in proximity to urban lakes in Wuhan City, China. With the expansion of Wuhan City, urban lakes became polluted, they shrunk or even disappeared, leading to unfavorable conditions for sustainable development of the city. To better understand the spatial relationship between the city and lakes, we classify the urban lakes in Wuhan central area into ′lakes in the urban center′ and ′lakes in urban fringe′. Based on housing price surface we explore the spatial characteristics in proximity to different lakes and differences between the lakes. We also use Geographic Information System(GIS) tool to calculate road density as a supplementary indicator to reflect the accessibility in proximity to urban lakes. The results indicate that relative independence exists between different towns, and the spatial characteristics are different depending on scales and locations. In most of cases, the road density is lower where closer to the lakeshore while the housing price exhibits an opposite pattern. We conclude that city governments and urban planners should give more considerations to these spatial differences, somewhere should be better planned and protected as an important waterfront and somewhere the control of unreasonable real estate development nearby should be strengthened.

Evaluating lake eutrophication with enhanced thematic mapper data in Wuhan

By analyzing the enhanced thematic mapper (ETM) images of September 1999, and quality observation data for many consecutive years in several parts of the Donghu Lake in Wuhan, China, the authors discovered a good linear relation between grey scale (GS) abstracted from ETM b5, b7 images and eutrophication level of the lakes, and extended the study to eight other major lakes in the area of Wu- han by using lake eutrophication models. Based on the in situ monitoring data, we also evaluated the eu- trophication level of the lakes with modified trophic index method brought by M. Aizaki et al. The results of the two methods showed that the most of the lakes were eutrophicated, and even hyper-eutrophicated in some areas. Six of the 8 lakes had very similar trophic state index (TSI) values. Although two of them differed in TSI value, but within an order, while it was different largely from the one by traditional method. The difference of the results between the two methods might have been due to three causative reasons. First, remote sensing technology reflects the overall status of a certain area corresponding to the ETM images in a certain period, but the modified TSI reflects the annual average values of the monitoring spots. Second, the time the ETM images taken is later than that of in situ data. Third, ETM images are affected by clouds, water depth, and suspended matter. In short, remote sensing result agreed greatly with the in situ monitoring data, indicating that remote sensing technology is feasible and effective for moni- toring and evaluating the lake eutrophication in the Wuhan area and it also can be used to evaluate large-scope lake eutrophication.

Status Survey on Street Trees in Donghu Hi-tech Development Zone in Wuhan City

Through typical sampling,the species,diameters at breast height (DBH) and growth status of street trees in Donghu Hi-tech Development Zone in Wuhan City were investigated;the characteristics and existing problems were analyzed.Constructive suggestions were put forward to enrich urban street tree species and outstand the characteristics of local species,so as to provide references to the street tree planning in Donghu Hi-tech Development Zone in Wuhan City.

A Journey to Wuhan

原文My fellows in Wuhan invited me there to enjoy a happy National Day and I could not agree more. It proved a glorious journey:a three-hour bus ride,a train to Wuchang station,I could not wait to visit the spots and my friends.

Structure of the Phytoplankton Community and Its Relationship to Water Quality in Donghu Lake, Wuhan, China

: The phytoplankton community structure, in terms of species composition, total standing crop, and abundance of the dominant algal species, at four stations in Donghu Lake, Wuhan, China, was investigated monthly from January 1994 to December 1996. A total of 260 taxa was observed, of which Chlorophyta (106 taxa) contributed the highest portion of the total number of taxa, followed by Bacillariophyta (82 taxa) and Cyanophyta (32 taxa). The total standing crop measured by means of chlorophyll a content, cell density, and cell biovolume, as well as the abundance of the dominant species, declined in the order of Station I to Station IV. Seasonal changes of the standing crop varied greatly among the four stations. Although the cell density at the four stations showed a single peak within a year, the peak density varied from July to November, dependent on the sampling year and the station. For chlorophyll a content and cell biovolume, multiple peaks were observed at Stations I and II, but a single peak was found at Stations III and IV. The phytoplankton community structure indicated that the trophic status was the highest at Station I (most eutrophic), followed by Station II; Stations III and IV were the least trophic areas. The long-term changes in phytoplankton community structure further suggested that changes in phytoplankton community structure were correlated with water quality, and eutrophication of Donghu Lake had been aggravated since the 1950s.

New desmids material from Donghu Lake,Wuhan,China

This paper reports two new species, one new variety and fourteen taxa new to China in three genera of the phytoplankton desmids from Donghu Lake, Wuhan, China.

Sequential fractionation of reactive phosphorus in the sediment of a shallow eutrophic lake——Donghu Lake, China

The bioavailability of phosphorus in lake sediment mainly depends on its forms. Therefore, reactive phosphorus (RP) pool of the sediment in a shallow eutrophic lake(Donghu Lake) was determined seasonally and spatially by sequential chemical extraction according to the scheme proposed by Psenner et al. (Psenner, 1985) and its modified version respectively. The ammonium chloride extracted 3%—7% of the total reactive phosphorus (Tot-RP), while the distilled water extracted less(<3%). These two forms of P were significantly higher at the most eutrophic stations(I and IV). The sum of BD-RP(reductant soluble P) and NaOH-RP extracted accounted for 57%—81% of Tot-RP, which could play significant roles in P cycling. The percentages of HCl-extractable RP in the sediments of station III, however, were usually much more than those of other stations, which could reflect the original geochemistrical characteristics and trophic status of the sediments. It was noted that the sediment RP in different fractions varied in different months studied.

SEASONAL CHANGES OF DISSOLVED AND PARTICULATE ORGANIC CARBON IN DONGHU LAKE,CHINA

Concentrations of dissolved and particulate organic carbon (DOC and POC) were documented in 1996-1997 at 4 different trophic state stations in Donghu Lake, a typical shallow eutrophic lake along the Changjiang River’s middle reaches. The mean concentrations of DOC were 15.11±3.26, 15.19±4.24, 14.27±3.43, and 13.31±3.30 mg/L in Station I, II, III, and IV, respectively. The DOC concentrations of the studied area were very similar to that in other lakes along the Changjiang River’s middle reaches. The POC mean of the whole lake was 5.01 mg/L due to the large amount of organic detritus of both allochthonous and autochthonous origin. Significant linear relationship was found between POC and chlorophyll a at all 4 stations, which presumably reflect that phytoplankton, its exudates and its metabolic products were the main contributors to the POC pool in the water column. The slope of such linear relationship at Station IV was significantly steeper than that at Station I, II and III. In addition, the DOC/POC ratios (mean value: 4.40) indicated that the organic detritus was the most important component of the particulate organic matter; in other words, next to organic detritus, phytoplankton dominated the particulate organic matter in Donghu Lake.

DONGHU LAKE ECOSYSTEM EXPERIMENTAL STATION

Location & environmental features: Donghu Lake is located at 114°23′ E and 30°33′N in the eastern suburbs of the city of Wuhan, capital of Hubei Province in central China. It is a typical shallow-bottomed, freshwater ecosystem nestling in the middle reaches of the mighty Changjiang (Yangtze) River. With a total surface area of 27.8 square and a mean depth of 2.2 meters, it sprawls in a drainage basin covering an area of 187 square kilometers. The station is situated on the southwest bank of the lake.

Hydrodynamic effects of reconnecting lake group with Yangtze River in China

The hydrodynamic effects of reconnecting a lake group with the Yangtze River were simulated using a three-dimensional hydrodynamic model. The model was calibrated and validated using the measured water temperature and total phosphorous. The circulation patterns, water temperature, and water exchange conditions between sub-lakes were simulated under two conditions： （1） the present condition, in which the lake group is isolated from the Yangtze River; and （2） the future condition, with a proposed improvement in which connecting the lake group with the Yangtze River will allow river water to be diverted into the lake group. The simulation period selected was characterized by extremely high temperature and very little rain. The results show that the cold inflow from the river has a significant effect on the water temperature only near the inlets, and the effect is more obvious in the lower water layers than that in the upper ones. The circulation pattern changes significantly and small-scale vortices only exist in part of the lake regions. The water exchange between sub-lakes is greatly enhanced with the proposed improvement. The water replacement rate increases with water diversion but varies in different sub-lakes. Finally, a new water diversion scheme was proposed to avoid contamination of some lakes in the early stage.

武汉市南湖2000—2021年水域面积时空变化分析

基于Landsat卫星数据,采用波段比值法获取2000—2021年武汉市南湖水域面积,分析南湖水域面积时空变化。结果表明:南湖2003年水域面积最大,水域面积在2000—2007年呈现缩小,2008—2012年呈现增大,2013—2021年又呈现缩小,南湖治理时间与水域面积增大时间点重合,说明湖泊治理取得了成效。南湖2000—2021年水域面积整体呈现缩小,面积缩小总量为1.02 km~2,且北面、东面的面积缩小变化最为明显,南湖水域面积在2004—2005年呈现突变性快速缩小。南湖水域面积与蒸发量存在正相关,南湖水域面积与气温存在负相关。指数平滑模型和神经网络模型(LSTM)都能预测南湖水域面积,且水域面积在2022—2024年呈现增大,但指数平滑模型预测结果更准确。

人民城市理念下景中村空间治理机制、困境与路径——以武汉东湖景区村落为例

人民城市的提出体现了中国之治在城市维度的新表达和城市治理理念的全新概括。城市景中村是我国城乡二元体制和风景名胜区保护制度下衍生出的一种特殊乡村形态,嵌入城市和风景区的空间之内,其特殊的空间组织、经济结构和社会关系凸显了景中村空间治理的复杂性和矛盾性,亟需厘清其治理和发展的现实困境,探索有效的治理路径。人民城市的景中村治理目标是建立各群体均衡的发展权、包容共享和公平公正的新型城乡关系。研究提出:1)人民城市空间治理机制体现了资本逻辑向人民逻辑转变的特征,内涵在于促进均衡的空间发展权力,最终实现属性、功能、组织的有机统一;2)景中村治理困境包括属性模糊、功能重构、组织无序三方面;3)景中村空间治理的实现路径包括治理规则创新、权属边界优化及行动机制建构,从而实现景中村的“生命共同体”。

城市体检社会满意度调查的理论逻辑与优化路径——以武汉东湖国家自主创新示范区为例

作为公众参与空间治理的重要手段,社会满意度调查为城市居民提供了主观判断和感知评价人居环境各种要素的平台,体现了“人民城市人民建”的价值导向。基于社会满意度调查的相关理论与研究基础,提出城市体检社会满意度调查的技术框架,通过深入识别主客观感知差异、指标优化与分析融合等方法提升社会满意度调查在城市体检中的应用价值,并以武汉东湖国家自主创新示范区为例进行实证研究,从价值认同、技术支撑和制度保障方面探讨人本视角下社会满意度调查的优化路径,从而完善人民城市治理主体与客体的沟通反馈机制。

基于SolVES模型的东湖风景区社会价值评估及提升策略

城市湖泊型风景区具有良好的生态系统服务社会价值,是城市规划关注的热点。对当前的城市湖泊型风景区,少有从生态系统服务社会价值方面进行评估和研究。以武汉东湖风景区为例,通过SolVES模型对其生态系统服务社会价值及其影响因素进行评估,结果表明:游客对武汉东湖风景区美学价值、生命可持续价值、生物多样性价值、科研教育价值和康养价值评价较高;美学价值、康养价值和科研教育价值主要集中在磨山、听涛及落雁景区的主要旅游景点,生物多样性和生命可持续价值在各景区广泛分布;水体、植被覆盖度、公共设施、旅游景点、科教文化设施、交通设施的建设会影响游客对社会价值的偏好。根据研究结果对武汉东湖风景区生态系统服务社会价值提出了提升策略。

武汉东湖水生植被的恢复试验研究

本文报道了在武汉东湖所作的水生植被恢复的研究结果．分别在东湖水果湖、汤林湖和后湖等三个湖建立水生植被恢复示范区．挺水植物莲Nelumbonucifera和芦苇Phragmitescommumis、浮叶植物菱Trapasp．和r－选择型的沉水植物苦草Vallisneriasp．、聚草Myriophyllumspicatum、菹草Potamogetoncrispus和大茨藻Najasmarina等在三个植被复示范区均可以恢复．而黄丝草Potamogetonmaackianus、伊乐藻Elodeacanadensis、黑藻Hydrillaverticillata等在后湖示范区可以恢复，在水果湖恢复未能成功．黑藻在汤林湖示范区也未能恢复．在水生植被演替动态研究和中试规模的恢复试验的基础上，提出了以东湖为代表的富营养浅水湖泊水生植被恢复对策．