Shifts of sediment bacterial community and respiration along a successional gradient in a typical karst plateau lake wetland(China)

Bacteria are important regulators of carbon cycling in lakes and are central to sediment ecosystem processes.However,the sediment microbial communities and their respiratory responses to the lake wetland succession are poorly understood.In this study,we collected sediment samples from four different succession points(the Potamogeton lucens zone,the Scirpus tabernaemontani zone,the Scirpus triqueter zone,and the Juncus effusus zone)in the Caohai Wetland of the Guizhou Plateau(China).The bacterial communities at these succession points were studied using a high-throughput sequencing approach.The sediment microbial respiration(SR)was measured using static chambers in the field and basal respiration(BR)was determined in the laboratory.The results show that the dominant bacterial taxa in the sediment was Proteobacteria(34.7%),Chloroflexi(17.8%),Bacteroidetes(7.3%),Acidobacteria(6.6%),and Cyanobacteria(6.1%).Principal coordinate analysis showed that the microbial community structure differs significantly at different sampling points along the successional gradient,indicating that the bacterial community structure is sensitive to the lake wetland succession.Different hydrological regimes and soil characteristics such as NH_(4)^(+)-N,Fe^(2+),Mn^(2+),and sediment organic carbon(SOC)content may be important factors responsible for the differences in the sediment microbial characteristics of the different successional stages in the Caohai wetland.Additionally,it was found that the SR increased significantly from the P.lucens zone to the J.effusus zone,but BR had the opposite response.The shifts in the bacterial community structure along the successional gradient may be the main reason for the observed differences in sediment respiration.

Landscape ecological assessment and eco-tourism development in the South Dongting Lake Wetland, China

As an important resource and the living environment of mankind, wetland has become gradually a highlight, strongly concerned and intensively studied by scientists and sociologists. The governments in the world and the whole society have been paying more and more attention on it. The Dongting Lake of China is regarded as an internationally important wetland. For a rational development and protection of the wetland, an investigation and studied on its resources and its value to tourism in the South Dongting Lake was conducted, to create an assessment system of the ecological landscapes, and to evaluate qualitatively and quantitatively the value of wetland landscape to the eco-tourism. The results showed that the scenic value of the South Dongting Lake Wetland satisfied the criterion of AAAA grade of China national scenic attraction. The eco-tourism value of the landscape cultures in the South Dongting Lake Wetland was discussed with emphasis. It were formulated that a principle and frame of sustainable exploitation of the wetland landscapes and it was proposed as well that establishing a Wetland Park and developing eco-tourism in the South Dongting Lake. Wetland is a fragile ecosystem with low resistance to the impact of the exploitation. Thus, we must pay intensively attention to the influence of exploitation on the landscape, take the ecological risk in account to employ a right countermeasure and avoid the negative affection.

Shrinking and Drying up of Baiyangdian Lake Wetland:A Natural or Human Cause?

The shrinking and drying up of wetlands in arid and semiarid areas of China have been widely observed in the recent years,but there has been no consensus on whether the aggravation is caused by human activities or by global climate warming.For a better understanding of the cause,this study investigates the dynamic changes of Baiyangdian Lake wetland over the last 40 years.It is shown that since the 1980s,Baiyangdian Lake has suffered from an insufficient water input and shrunk considerably.By using SPSS11.0,this study undertakes a detailed analysis on the significance of the effects of the possible driving factors for the degradation.It is identified that the North China Plain has been warming up significantly in recent years,which causes a significant reduction in the precipitation and inflow to the lake.Although human disturbances such as the irrigation and storage of water in reservoirs do not play a decisive role,they accelerate the degradation and their effects should be minimized.

Assessment on soil fertility of Dongting Lake wetland area (China) based on GIS and fuzzy evaluation

Using soil data of the Second National Field Survey,the soil fertility of wetland ecosystem of Dongting Lake was evaluated by using the technology of GIS and method of fuzzy evaluation.Integrated with the wetland actuality of Dongting Lake and particularity of paddy,seven factors (including soil organic matter,total nitrogen,total phosphorus,total potassium,available phosphorus,available potassium,and pH value),closely related with soil fertility,were chosen to establish the index system of synthetical evaluation.Based on the effect degree of each selected index on soil fertility,a judgment matrix was built,and the weight coefficient was determined by the method of correlation coefficient.Finally,under the support of the spatial analysis module of GIS (Geographic Information System),the spatial distribution properties of soil fertility in wetland ecosystem of Dongting Lake were studied.The results show that the soil fertility of Dongting Lake wetland ecosystem is not very good,and the area of type III and type IV achieves 69.8%.As a result,many countermeasures should be taken to improve the soil fertility.As for the spatial properties,the soil fertility level of central and west Dongting Lake is much higher than that of north and south part.The soil fertility of paddy field surpasses that of red soil,and the contents of soil organic matter and total nitrogen in paddy field are large.

THE PRELIMINARY STUDY ON LANDSCAPE CULTURE ORIENTATION AND EXPLOITATION OF THE SOUTH DONGTING LAKE WETLAND

Dongting Lake is internationally a n important wetland.We studied and s ummarized the conception,func-tion,classification and current situation of the wetland-landscape cu lture in this region.The results showed that the cul-ture of Dongting Lake wetland was ric h in diversity,which are the Rice Cul tivation Culture,high-balustrade dwelling,Nuo Culture,Ship Culture,Dragon Bo at Culture,Chu Culture,Ancient Arc hitecture Landscape,Wetland Foodstuff and Cuisine Culture,Civil Art,Historic Heritage and Cultural Relics,Revolutionary Sites and Ruins,and Production and Living Culture,etc.We also evaluated the eco-tourism value of wetland l andscape culture,and analyzed its f eatures and orientation.The results revealed t hat the south Dongting Lake wetland p lays a key role on the Changjiang(Yangtze)River reaches civilization and Chinese civilization,even has great influence on the global civilization.We summ arized that the soul of the south Dongting Lake Cultu re was Wetland Culture,Water Cultur e,Rice Cultivation and Chu Culture.The thoughts,principles and approaches of sustainable exploitation and ut ilization of the wetland landscape c ulture were formulat-ed and suggested.

Population sizes and group characteristics of Siberian Crane(Leucogeranus leucogeranus) and Hooded Crane(Grus monacha) in Poyang Lake Wetland

Both the Siberian Crane(Leucogeranus leucogeranus) and Hooded Crane(Grus monacha) have limited population sizes and are considered endangered by domestic Chinese and international agencies.To document the current size of their respective populations and characterize their groups,between October 2012 and April 2013 we undertook fieldwork at four nature reserve areas within the Poyang Lake wetlands.We divided Poyanghu National Nature Reserve(PYH) into the Wucheng(PWC) and Hengfeng areas(PHF),because each are each located in different counties.Our fieldwork showed that the Siberian Crane occurred mainly in PYH(364 in the PHF,158 in the PWC) and the Nanjishan Wetland National Nature Reserve(NJS,with 200 individuals).The Hooded Crane was mainly distributed in PYH(302 in the PHF and 154 in the PWC).Family groups accounted for more than 50% of the total number of groups among both species,with Hooded Cranes forming more family groups than Siberian Cranes.Typically,these groups were formed of two adults with one offspring(Siberian Crane),and two adults with two offspring(Hooded Crane),with the mean family group size of the Siberian Crane and Hooded Crane being respectively 2.65±0.53(n=43) and 3.09±0.86(n=47) individuals per group.The mean collective group size of the Siberian Crane and Hooded Crane included 28.09±24.94(n=23) and 28.94±27.97(n=16) individuals per group,respectively,with the proportion of juveniles among Hooded Cranes being more than double that seen among the Siberian Cranes.

Mapping of Freshwater Lake Wetlands Using Object-Relations and Rule-based Inference

Inland freshwater lake wetlands play an important role in regional ecological balance.Hongze Lake is the fourth biggest freshwater lake in China.In the past three decades,there has been significant loss of freshwater wetlands within the lake and at the mouths of neighboring rivers,due to disturbance,primarily from human activities.The main purpose of this paper was to explore a practical technology for differentiating wetlands effectively from upland types in close proximity to them.In the paper,an integrated method,which combined per-pixel and per-field classification,was used for mapping wetlands of Hongze Lake and their neighboring upland types.Firstly,Landsat ETM+ imagery was segmented and classified by using spectral and textural features.Secondly,ETM+ spectral bands,textural features derived from ETM+ Pan imagery,relative relations between neighboring classes,shape features,and elevation were used in a decision tree classification.Thirdly,per-pixel classification results from the decision tree classifier were improved by using classification results from object-oriented classification as a context.The results show that the technology has not only overcome the salt-and-pepper effect commonly observed in the past studies,but also has improved the accuracy of identification by nearly 5%.

Ecosystem Health Assessment of Honghu Lake Wetland of China Using Artificial Neural Network Approach

Honghu Lake,located in the southeast of Hubei Province,China,has suffered a severe disturbance during the past few decades.To restore the ecosystem,the Honghu Lake Wetland Protection and Restoration Demonstration Project(HLWPRDP) has been implemented since 2004.A back propagation(BP) artificial neural network(ANN) approach was applied to evaluatinig the ecosystem health of the Honghu Lake wetland.And the effectiveness of the HLWPRDP was also assessed by comparing the ecosystem health before and after the project.Particularly,12 ecosystem health indices were used as evaluation parameters to establish a set of three-layer BP ANNs.The output is one layer of ecosystem health index.After training and testing the BP ANNs,an optimal model of BP ANNs was selected to assess the ecosystem health of the Honghu Lake wetland.The result indicates that four stages can be identified based on the change of the ecosystem health from 1990 to 2008 and the ecosystem health index ranges from morbidity before the implementation of HLWPRDP(in 2002) to middle health after the implementation of the HLWPRDP(in 2005).It demonstrates that the HLWPRDP is effective and the BP ANN could be used as a tool for the assessment of ecosystem health.

Measuring benefits of Dianchi Lake wetland based on GIS RS GPS technology

Based on the collection data of the plants, water quality, soils of Dianchi Lake, and combined high resolution satellite remote sensing images, the paper analyzed evolution law of Dianchi Lake wetland, and evaluated the benefi ts of Dianchi Lake wetland from the perspective of economy, environment, society and zoology. The results showed that the area of wetland and plant community account for 92.2% in lakeside zone, the increase was 141.4% compared with the value of 2007. The total value of evaluated benefi ts of Dianchi wetland increased 3.439 billion yuan, and ecological environment improved gradually.

Influences of 500 kV Transmission Lines on Wetland Ecosystem and Its Protective Countermeasures--A Case Study of the Lake Wetland Natural Reserve along the Yangtze River in Anqing City

The impact of 500 kV transmission lines of Anqing power plant across the lake wetland reserve along the Yangtze River on the safety of the ecosystem was taken as the researched object.The power frequency electric field intensity(PFEFI),power frequency magnetic field intensity(PFMFI),radio interference,construction noise,vegetation destruction and the influence on water quality were investigated and monitored,and the influences of PFEFI,PFMFI,radio interference and construction noise on wild animals,especially the habitats and migration of birds were mainly researched.The direct and indirect influences on the surrounding environment as well as plants and animals in sensitive areas were analyzed and predicted.The results firstly showed there existed a 182 400m^3 stereo-space(PFEFI>4kV/m)which made flying birds unsafe under the lowest height 11 mof the lines,which fills the gap in the research of this field.Finally,some operational protection countermeasures were put forward at the current technical level to achieve the win-win goal of economic development and natural protection.

Valuation of Air Regulation Service Value in the Honghu Lake Wetland

To assess the value of air regulation in the Honghu Lake Wetland,a quantitative study was conducted based on existing literatures. Results showed that the total service value of air regulation in the Honghu Lake Wetland was 254. 52 million yuan/a,which was 11. 6 times of that by previous studies. The net value of fixed greenhouse gases via wetland plants( including carbon emission value from methane emission conversion into carbon dioxide greenhouse gas effect) was 58. 50 million yuan/a,the data indicated that this lake wetland was a strong carbon sink. The value of oxygen released by the wetland ecosystem was 176. 51 million yuan/a,and the value of regulating air humidity and temperature was 19. 51 million yuan/a. The net value of greenhouse gases fixed by the Honghu Lake Wetland vegetation,the value of released oxygen,and the value of lifting air humidity and temperature regulation accounted for 22. 98%,69. 35%,and 7. 70% of the total value of the air regulation services,respectively.

Ecological Landscape Design of Urban Wetland Park: A Case Study of the Aixi Lake Wetland Park in Nanchang City

Wetland as one of the natural landscapes with the richest biodiversity and most closely related to our life is widely distributed all around the world, and capable of storing fl ood, preventing drought, purifying environment, adjusting climate, controlling pollution, maintaining regional ecological balance. Nanchang is famous for "City in the Lake and Lake in the City", and this paper begins with wetland resources in Nanchang City, analyzes problems of local wetlands. Taking the design of the Aixi Lake Wetland Park for example, this paper proposes suggestions for the renovation and improvement by analyzing the problems of its current landscape pattern, and specifi c problems in the landscape design of wetland park, and summarizes the ecological model fi t for the landscape design of urban wetland park in Nanchang City. The research contributes to the ecological restoration and conservation of wetland resources in Nanchang.

Construction and Protection of Qionghai Lake Wetland Ecosystems

Wetland is closely related to survival, reproduction and development of human beings. Due to population growth, industrialization, urbanization and agricultural modernization, wetland ecosystems are suffered from huge pressure of human society and the wetland ecological environment becomes extremely vulnerable. On the basis of analyzing current situations of Qionghai Lake wetland in Xichang City of Sichuan Province, this paper discussed the significance of Qionghai wetland construction and protection, and offered countermeasures and recommendations for solving existing problems in Qionghai wetland.

Application of Community Climate Change Adaptation Assessment Tools for Climate Adaptation Planning in Yala Wetlands Complex, Lake Victoria Basin, Kenya

Yala Wetland is a complex of Nzoia and Yala rivers that drain their waters into Lake Victoria, but face various pressure which is thought to originate from the impacts of climate change. The riparian communities are generally poor and use the wetland resources for small-holder livelihood activities. This paper describes how community climate change adaptation assessment (C3A2) tools were applied to identify resilient community-level adaptation options and would inform local climate adaptation planning. Eight participatory C3A2 tools were applied for data collection in which two (adaptation attributes and story-telling) were administered at the meso or local government (County) level while all the eight tools (community protocol, risk mapping, techno-transect, resilience ranking, community calendars, story-telling, adaptation attributes and give back) were administered at the micro or community level. Qualitative research method was adopted and 80 respondents (20 at meso and 60 at micro) were purposively selected for the study. Data were collected through interviews, focus group discussions (FGD), and plenary discussions. Data were analyzed at four levels: pre-analysis in situ, daily team triangulation, team conclusions, and cross-community reporting. The study found that communities experienced climate risks that tended to shift along with prolonged and irregular hydro-meteorological events, which affected their capacities for adaptation especially the resource-constrained individuals and vulnerable households. Drought (45%) and flood hazards (39%) were the most felt strongly. Drought was manifested mainly by prolonged dry-spell, increased atmospheric temperatures, and strong winds while floods were characterized by unpredictable and short but high-intensity rainfall with associated loss of lives and property damage. Women, children, and poor households were the most exposed to climatic hazards. Farm/agro-forestry was the most perceived adaptation strategy for drought, flood, and soil erosion while alternative livelihoods particularly ecotourism was the commonly perceived adaptation strategy for human-wildlife conflict (HWC). Three community-based adaptation action plans (CBAP) were prepared to guide future village-level planning and development. The CBAPs were used to identify three sample projects which were funded by the donor and implemented by the community. The C3A2 approach provides adequate participatory tools that can be applied in the lake and river basins, and potentially other ecosystems to guide the development of community-based adaptation plans and resilient community-based adaptation projects with wider local acceptance especially those geared towards designing programs for climate-smart livelihoods. However, the application of the methodology may be site-specific and the tools can be administered based on local scenarios and the availability of resources.

Characteristics of the Distribution of Plant Community in Lakeshore Wetland of Yunnan Plateau

[ Objective] The aim was to discuss the distribution of plant community in lakeshore wetland of Yunnan Plateau. [ Method ] Taking sever- al lakes in Yunnan Plateau as example, the distribution characteristics and rules of plant community in lakeshore wetland of Yunnan Plateau were discussed. The degradation and causes of lakeshore wetland were analyzed. [ Resultl The wetland plants were characterized by reduction of the aquatic plant species, the decline of the species diversity and the biomass. Fast breeding vegetation with high fat and pollution tolerance, strong adaptability was easy to form a single optimal community. Some representative and sensitive to pollution plants deteriorated or destroyed. These phenomena reflected the changes of water quality, the worse pollution, eutrophication and the acceleration of turning wetland to land. The causes of wetland degradation and biodiversity included increase of population pressure, industrial and agricultural development, advance of urbanization, unreasonable cultivation, over-exploitation and eutrophication, etc. [ Conclusion] The study provided theoretical basis for the protection, environ- ment evaluation and sustainable development of lakeshore wetland.

A Comparison of Habitat Use by Wintering Bean Goose and Common Crane in Yeya Lake Wetlands

Identifying the habitat use in relation with time between 2 bird species in a wetland can help our understanding of how wintering bird species interact and coexist in the same system.The detection probabilities of Bean Goose(Anser fabalis)and Common Crane(Grus grus)were investigated in Yeyahu Wetland Nature Reserve in Beijing over a whole wintering season.Moreover,how use proportion of each type of habitats varied with time for 2 bird species was explored.In the detection probability study,the method of fixed-radius point was used to observe and infer the presence of species.An occupancy model was applied to deal with the occupancy of a sampling unit,accounting for imperfect detection.In the survey for habitat use,the types of habitats that 2 bird species were occupying were investigated by a line-transect method.Then,the method of multinomial logistic regression was applied to compare the proportions that various types of habitats were used during the days after 2 bird species arrived.The parameters of the detection probability model and multinomial logistic regression equation in a Bayesian framework using Markov Chain Monte Carlo(MCMC)simulations were estimated.The detection probability model was used to predict that Bean Goose arrived in Yeya Lake Wetlands in the middle of October and left at the end of March next year,whereas Common Crane arrived at the end of October and left in the middle of April next year,with almost 5 months coexisting in Yeya Lake Wetlands.The result of the multinomial logistic regression showed Bean Goose gradually decreased use proportion of the water but increased use proportion of grassland over time,and use proportion of farmland remained constant at the beginning but declined later.Common Crane decreased use proportions of the water and grassland but increased that of farmland over time.Common Cranes were more competitive for farmland habitat.It was implied that Bean Goose and Common Crane adjusted and segregated the use proportion of grassland and farmland during their wintering period,which might mitigate interspecific competition and allow for coexistence.It was suggested that adequate habitats of grassland and farmland were probably important requirement enabling habitat segregation and coexistence of Bean Goose and Common Crane and that the overall habitat quality of a wintering site was likely to incorporate the availability of these resources,which provided multiple fitness advantages through secured food supplies and reduced predation risk.Thus,habitats providing adequate food supplies and protection might be unsuitable wintering habitats given an improper agricultural landscape management.Finally,it was proposed that maintenance of habitat diversity and improved farming methods,such as stoping crop residue burning and delaying the time of plowing,could be incorporated in agricultural landscape management plans on habitats of Bean Goose and Common Crane.

Valuation of Lake and Marsh Wetlands Ecosystem Services in China

Wetlands are highly productive natural ecosystems, providing valuable goods and services. There is growing interest in transferring ecosystem service value from the existing wetlands studied to other wetlands ecosystems at a large geographic scale. The benefit transfer method uses the known values from wetlands to predict the value of other wetland sites. This methodology requires only limited time and resources. The present study calculated the value of the ecological services provided by lake and marsh wetlands in China in terms of biodiversity indices, water quality indices and economic indices. Basic data on wetlands were obtained through remote sensing images. The results show that: 1) The total ecosystem service value of the lake and marsh wetlands in 2008 was calculated to be 8.1841 × 1010 United States Dollars(USD), with the marsh and lake wetlands contributing 5.6329 × 1010 and 2.5512 × 1010 USD, respectively. Values of marsh ecosystem service were concentrated in Heilongjiang Province(2.5516 × 1010 USD), Qinghai Province(1.2014 × 1010 USD), and Inner Mongolia Autonomous Region(1.1884 × 1010 USD). The value of the lakes were concentrated in Tibet Autonomous Region(6.223 × 109 USD), Heilongjiang(5.810 × 109 USD), and Qinghai(5.500 × 109 USD). 2) Waste treatment and climate regulation services contributed to 26.29% and 24.74% respectively, of the total ecosystem service value of the marsh wetlands. Hydrological regulation and waste treatment contributed to 41.39% and 32.75%, respectively, of the total ecosystem service value of the lake wetlands. 3) The total ecological service value of the lake and marsh wetlands was 54.64% of the total service value of natural grassland ecosystems and 30.34% of the total service value of forests ecosystems in China.

Effects of Water-table Depth and Soil Moisture on Plant Biomass, Diversity, and Distribution at a Seasonally Flooded Wetland of Poyang Lake, China

Hydrological regime has been widely recognized as one of the major forces determining vegetation distribution in seasonally flooded wetland. Poyang Lake, the largest freshwater lake in China, has been encountering dramatic changes in hydrological conditions in last decade, which greatly influenced the wetland vegetations. To explore the relationships between hydrology and vegetation distribution, water-table depth, soil moisture, species composition, diversity and biomass were measured at a seasonally flooded wetland section at Wucheng National Nature Reserve. Three plant communities, Artemisia capillaris, Phragmites australis and Carex cinerascens communities, were examined which are zonally distributed from upland to lakeshore with decreasing elevation. Canonical correspondence analysis(CCA), spearmen correlation and logistic regression were adopted to analyze the relationships between vegetation characteristics and hydrological variables of water-table depth and soil moisture. Results show that significant hydrological gradient exist along the wetland transect. Water-table demonstrates a seasonal variation and is consistently deepest in A. capillaris community(ranging from –0.5 m above ground to +10.3 m below ground), intermediate in P. australis community(–2.6 m to +7.8 m) and shallowest in C. cinerascens community(–4.5 m to +6.1 m). Soil moisture is lowest and most variable in A. capillaris community, highest and least variable in P. australis community, and intermediate and moderate variable in C. cinerascens community. The CCA ordination indicated that variables of water-table depth and soil moisture are strongly related to community distribution, which explained 81.7% of the vegetation variations. Species diversity indices are significantly positively correlated with soil moisture and negatively correlated with moisture variability, while above- and belowground biomass are positively correlated with moisture. Above- and belowground biomass present Gaussian models along the gradient of average water-table depth in growing season, while species diversity indices show bimodal patterns. The optimal average water-table depths for above- and belowground biomass are 0.8 m and 0.5 m, respectively, and are 2.2 m and 2.4 m for species richness and Shannon-Wiener indices, respectively. Outcomes of this work improved the understandings of the relationship between hydrology and vegetation.

Wetland vegetation biomass estimation and mapping from Landsat ETM data: a case study of Poyang Lake

Poyang Lake is the largest freshwater lake in China. This paper conducted a digital and rapid investigation of the lake’s wetland vegetation biomass using Landsat ETM data acquired on April 16, 2000. First, utilizing the false color composite derived from the ETM data as one of the main references, the authors designed a reasonable sampling route for field measurement of the biomass, and carried it out on April 18–28, 2000. Then after both the sampling data and the ETM data were geometrically corrected to an equal-area projection of Albers, linear relationships among the sampling data and some transformed data derived from the ETM data and the ETM 4 were calculated. The results show that the sampling data is best relative to the band 4 data with a high correlation coefficient of 0.86, followed by the DVI and NDVI data with 0.83 and 0.80 respectively. Therefore, a linear regression model, which was based on the field data and band 4 data, was used to estimate the total biomass of entire Poyang Lake, and then the map of the biomass distribution was compiled.

Temporal changes in wetland plant communities with decades of cumulative water pollution in two plateau lakes in China's Yunnan Province

Wetland plant communities in the plateau lakes of Yunnan Province, China, have decreased significantly over the past decades. To better understand this degradation, we analyzed the processes and characteristics of changes in wetland plant communities in two of the largest lakes in Yunnan Province, Dianchi and Erhai lakes. We collected records of native and alien plant communities in the two lakes from literature published from the 1950 s to current period. We calculated plant community types and their area in some historical periods when related data were reported, and analyzed the relationship between changes in plant communities and water pollution. InDianchi Lake, 12 community types of native plant communities, covering over 80% of the surface in the 1950 s and 1960 s, were reduced to four types covering 2.4% by the late 2000 s. Alien plant communities started to appear in the lake in the late 1970 s, and have since come to cover 4.9% of the lake surface,thereby becoming dominant. In Erhai Lake, 16 community types of native plant communities,covering 47.1% of the lake surface in the late 1970 s,declined to 10 community types, covering 9.3% of the surface, by the late 2000 s. Alien plant communities appeared in the middle 1980 s, and at present cover 0.7% of the surface area. It was indicated that changes in plant communities were significant related to water eutrophication. The area occupied by native and alien plant communities was, respectively, negatively andpositively related to the content of nutrients in water.This showed lacustrine pollution played an important role in native plant loss and alien plant invasion in the two plateau lakes.