Forages are easy to cultivate and have high biomass and high yields, which endows its broad application prospect in heavy metal-contaminated soil. Forages are available as both low-accumulation for feed or high-accumulation for phytoremediation. Meanwhile, forages are also important plants for biomass energy and soil pollution remediation. The advantages, accumulation characteristics, response mechanism of forages in the treatment of heavy metal contaminated soil, and the application and benefit evaluation of main forage grasses in the treatment of heavy metal contaminated soil were reviewed. The excellent forage species of Gramineae and Leguminosae with potential for remediation of heavy metal contaminated soils in China were identified and analyzed. The varietal differences on absorbing and accumulating heavy metals, the response and mechanism of forage under single/compound metal stress were also described. The review is intented to provide theoretical basis and practical reference for the treatment of heavy metal contaminated soil by forages and the comprehensive utilization of the forages.

The existence of mountains-rivers-forests-farmlands-lakes-grasslands systems emphasises the need for ecosystem integrity and reflects the relationships among natural ecosystems. The construction of ecological security pattern can connect fragmented habitats, thereby improving the stability of the ecosystem and maintaining regional ecological security. Using the literature analysis method, the logical line of "planning and design of pattern elements-sources identification-resistance surface setting and modification-corridor extraction-pattern optimization and effectiveness evaluation-application of research results" was taken for combing out each important link in constructing ecological security pattern based on minimum cumulative resistance model, clearing and analyzing the current research points and existing problems of each link, so as to make suggestions and to point out the direction of future development. The results show that: (1) For the identification of ecological sources, a combination of direct and indirect identification should be adopted to meet the needs of management and supervision in practice. (2) At present, resistance surface construction methods mainly include scoring assignment based on land cover and ecosystem service assignment, which have the disadvantages of strong subjectivity and poor applicability. Relevant index systems should be improved to promote the scientific nature of the ecological resistance surface assignment; (3) Compared with the ecological red line, the ecological network emphasises the connectivity of the landscape. The layout of the ecological red line can be optimised through corridors and nodes. (4) Compared with other methods, the minimum cumulative resistance model has the advantages of applicability and compatibility. However, in the future, it is still necessary to strengthen the researches on multi-path analysis and ecological nodes, pay more attention to the difference of the spatial scale of the research object, and improve the objectivity and applicability of the model.

Exploring the trade-offs and synergies between regional ecosystem services and the allocation of environmental resources is critically important for guiding the management of ecological environment. Data on land use, meteorological observations, and soil and socio-economic statistics were collected in 2000, 2010, and 2018 to characterize spatio-temporal changes in four types of ecosystem services, including water conservation, soil conservation, carbon sequestration, and biodiversity maintenance in the Three Gorges Reservoir Area. The trade-offs and synergies between ecosystem services were analyzed at two spatial scales: the global scale and comprehensive zoning based on hot spots. The results show that: (1) From 2000 to 2018, water conservation and soil conservation services in the Three Gorges Reservoir Area first decreased and then increased, and there was a significant change in their spatial pattern. Carbon fixation increased annually, with a total increase of 11.45% from 2000 to 2018. The spatial pattern of biodiversity remained unchanged, but there was a small decrease in 2018; thus, the risk of ecological degradation requires increased attention. (2) In the Three Gorges Reservoir Area, the proportion of non-hot spot areas, type 2 hot spot areas, and type 4 hot spot areas first increased and then decreased; the proportion of type 1 hot areas and type 3 hot areas first decreased and then increased. (3) There was synergy between all types of ecosystem services in the Three Gorges Reservoir Area at the global scale, and the correlation coefficients of ecosystem services between different hot spots and global scale were significantly different because of variation in regional land-use types and natural resources.

Exploring the spatiotemporal changes of landscape ecological risk and assessing the ecological risk situation is important for maintaining regional ecological security and sustainable economic and social development. Landscape pattern index, spatial autocorrelation analysis and geodetector analysis methods were used in this study to explore spatial-temporal variation characteristics and factors influencing landscape ecological risk in Jiangjin District of Chongqing at the optimal spatial scale based on remote sensing images in 2000, 2009 and 2018. The results reveal that: (1) With changes in grain size and extent, different regularities were exhibited in landscape indexes. A pixel size of 90 m and a grid size of 3 km better reflected the spatial heterogeneity of landscape patterns; (2) Spatial patterns of landscape ecological risk in the study area changed substantially, the overall threat degree of landscape ecological risk increased and the medium-risk area gradually became the dominant type of the region from 2000 to 2018; (3) There was marked spatial concentration of landscape ecological risk in each period of the study area, and the spatial distribution of the landscape ecological risk index mainly exhibited a high-high aggregation pattern and a low-low aggregation pattern; (4) Human activity had an increasingly strong impact on regional landscape patterns and ecosystems. Population density and gross domestic product were important driving factors affecting the spatial and temporal distribution of landscape ecological risks. These results could provide decision-making references for the construction of important ecological barriers in the upper reaches of the Yangtze River.

Using MOD13Q1 as the data source, by adopting the analysis method of fixed starting year and increased ending years, and supplemented by Sen+Mann-Kendall slope method and Hurst index methods, the characteristics and driving forces of the changes of vegetation cover in Hangjin County from 2000-2017 was investigated. The results show that: (1) the spatial distribution pattern of vegetation cover in Hangjin County showed "high-low-high" trend from north to south; a greening-browing trend was observed in the significantly increased area of normalized difference vegetation index (NDVI), while the degraded area had a first downward and then upward trend; (2) the mean NDVI value presented an order: agricultural land > forest > shrub > grassland > sandland under the different land use types, and the increase rate of NDVI in forest, shrub and grassland was significant while sandy land was the lowest; (3) the main trend of NDVI in the study area is degradation, accounting for 57.93% of the total area of the Hangjin County, and precise measures should be taken to strengthen ecological protection in this region; (4) precipitation had a positive effect on NDVI, whereas temperature did not promote vegetation grown and the correlation decreased with time period lengthening; and human activities had a dual effect on NDVI; (5) the driving forces of each period exhibited a complicated status gradually, and the interactions of climate variations and human activities had significant effects on NDVI.

In April-June, 2016-2018, line transect method was used to investigate the species diversity of breeding birds in Guanshan region. The results show that 142 species, belong to 42 families from 14 orders, were found in Guanshan area during breeding season. The region possesses both characteristics of the Oriental realm and the Palaearctic realm. In this region, the avian community diversity index was 3.985 6, the evenness index was 0.804 2, and the dominance index was 0.030 2. According to different vegetation and altitude, the survey area was divided into four habitat types: low altitude farming belt, mid-altitude deciduous broad-leaved forest belt, mid-high altitude coniferous broad-leaved mixed forest belt, and high altitude subalpine meadow belt. The mid-altitude deciduous broad-leaved forest belt had the most species quality and highest diversity and evenness index, while the mid-high altitude coniferous broad-leaved mixed forest belt had the highest bird density, and the high altitude subalpine meadow belt had the highest bird dominance index. The similarity index was generally higher between adjacent habitats than between separate habitats. The bird species richness in different habitats showed some differences, but the inter annual variation of species richness in the entire study area and the same habitat zone was not obvious. The composition of dominant species was distinctly different in four habitat belts, and basically no change between the years. According to the different food habits of various birds, they can be divided into four feeding groups. When correlated to elevation, the highest bird species richness was found in those habitats at mid-elevation. Guanshan in Longxian County is an important channel for the migration and communication of some birds. Through the research and analysis of the structure and diversity of Guanshan breeding birds community, it provides relevant basic data for future conservation of bird diversity.

Xishuangbanna in the Southwest of China's Yunnan Province holds highest concentration of biodiversity, but in the recent decades the land use in the region has undergone tremendous changes. Tropical forests have been gradually replaced by rubber plantations. Here, the impact of forest-rubber mosaic patterns on the composition and diversity of arthropod communities was explored by analysing the key drivers of distribution pattern between different habitat types. The result of the study provides relevant insights to develop effective protection of the remaining forests in Xishuangbanna. The understory arthropod diversity and community composition between rubber plantations and forest fragments in Nabanhe National Nature Reserve in Xishuangbanna were compared using metabarcoding techniques. The relationship between arthropods and environmental factors was analyzed, and the key factors that influencing arthropod community structure in a rubber landscape matrix were discussed. The results of the study based on metabarcoding technique showed that a total of 397 OTUs were obtained from rubber plantations and forest, which belong to 18 orders in the forest, a total of 347 OTUs were collected, with 136 OTUs collected from rubber plantations. Between habitat types, compared to primary forests rubber plantations had a significant negative effect on arthropod richness. The results of nonmetric multidimensional scaling analysis (NMDS analysis) show that the composition of arthropod community in rubber plantations and forest fragments was significantly different showing that Beta diversity of forest fragments is higher than that of rubber plantations. Within the landscape scale, the main factors affecting the species diversity of arthropods were natural forest cover and slope. Whereas in the local scale, the main factors influencing the diversity of arthropods in rubber plantation were the age of the rubber trees, altitude and distance to the edge of the forest. In the forest, the main factors influencing the diversity of arthropods were forest area, altitude, aspect, tree diversity and distance to the edge of the forest. This study demonstrates that rubber plantation has a significant negative impact on forest ecosystems and arthropod diversity. In the mosaic landscape pattern, forest cover, tree diversity, the distance between rubber plantation and the edge of the forest played a significant role in arthropod diversity. It is significantly beneficial to biodiversity conservation when the forest coverage is over 50%. The present findings from this study can provide important management basis for the conservation of biodiversity in Xishuangbanna.

The effects of global warming and biochar addition on farmland soil nutrients and microbial biomass were studied to provide a theoretical reference for the application of biochar in agricultural production. An open-top chamber (OTC) was used to simulate warming. Different temperature gradients-CK (no warming ), T1, T2 and T3-were set, with the addtion of bamboo biochar at 20 t·hm^-2 (BC1) and no addition (BC0). The results show that compared with the average temperature of CK the OTC average temperature of T1, T2 and T3 increased by 0.5, 1.0 and 1.6 ℃, respectively, As temperature rose alone (without the addition of bamboo biochar), soil organic matter (SOM), total nitrogen (TN), total potassium (TK), alkaline hydrolysis nitrogen (AN), available phosphorus (AP), rapidly available potassium (AK) increased at extremely significant level. The microbial biomass carbon (MBC) of T1, T2 and T3 increased by 70%, 72.4% and 114.39%, respectively, compared with CK. As temperature rose alone, the microbial biomass nitrogen (MBN) of T1, T2 and T3 increased by 45.02%, 71.71% and 72.23%, respectively, compared with CK. Compared with the microbial biomass P (MBP) of CK, as temperatures rose alone, the microbial biomass P of T1, T2 and T3 increased by 39.43%, 73.71% and 202.31%, respectively All the above increases were at extremely significant level (P<0.01). When biochar was added alone (without increasing of temperature), SOM, TN, TK, and AK reached extremely significant level, and the total phosphorus (TP ) reaching to significant level. MBC, MBN and MBP all showed an increasing trend at significant level (P<0.05). When warming and biochar addition were combined, the contents of soil MBC, MBN and MBP increased by 154.34%, 87.85% and 197.60%, respectively, compared with treatment without warming and biochar addition. The combined action of warming and biochar can increase the soil pH, TN, AN, AP and the MBN/TN ratio at extremely significant level, and the increase of SOM at significant level. Correlation analysis and redundancy analysis show that the effect of soil properties on changes of microbial biomass was in the order of SOM>AP>AK>AN>TK>PH>TP>TN. SOM, AP and AK are the main factors affecting soil microbial biomass. Under the stress of global warming, adding biochar can increase soil microbial biomass by accelerating the cycling of soil elements.

To investigate the levels, compositions, distributions and sources of PAHs in the surface soil of Altay, Xinjiang. Totally 14 samples collected from the surface soil in October 2018 were analyzed for 16 USEPA priority PAHs by gas chromatography-mass spectrometry (GC-MS). The total PAHs concentrations ranged from 3.48 to 103.81 ng·g^-1, with an average of 32.24 ng·g^-1, which were mainly composed of three-rings and four-rings PAHs. In addition, the total concentrations of seven carcinogenic PAHs ranged from 0.32 to 50.95 ng·g^-1, with an average of 11.20 ng·g^-1. Lower levels of PAHs contamination were found in surface soil of study area, and there was no significant correlation between PAHs level and altitude (r=-0.471, P=0.668). The results of PAHs isomeric diagnosis ratios show that the main sources of soil PAHs in Altay Area were fossil fuels and biomass combustion, and vehicle emissions contributed more to PAHs. Three sources including vehicle emissions, coke ovens and coal combustion, and biomass combustion were quantified by the PCA-MLR model, accounting for 62.8%, 28.2% and 9.0% of the total PAHs, respectively. Compared with emission contribution sources in 2012 of Xinjiang, the vehicle emissions, coke ovens and coal emissions showed an increasing trend.

To investigate the soil pollution characteristics caused by coking industry production activities, a total of 1 437 soil samples were collected from three abandoned coking plants in Beijing, Chongqing and Taiyuan, with a maximum sampling depth of 40 m. 16 polycyclic aromatic hydrocarbons (PAHs) that are in the controlling list of US EPA was determined via gas chromatography-mass spectrometry (GC-MS). The maximum contents of ΣPAHs of the three coking plants were 10 647.2 mg·kg^-1(Beijing), 39 332.7 mg·kg^-1 (Chongqing)and 19 381.9 mg·kg^-1 (Taiyuan) respectively. The results indicate that the soils were severely contaminated by PAHs. Toxic equivalent factors (TEF) show that the carcinogenic high-cyclic PAHs were main toxic substances that accounts for more than 90% of the total toxicity contribution. The maximum concentrations of the eight PAHs, preferentially controlled according to the GB 36600-2018, decreased rapidly with the increase of depth. The decrease rate in the soil in the Chongqing coking plant was significantly lower than that of the other two sites, and this phenomenon was more obviously for high molecular weight PAHs. The PAHs derived from coal combustion in the three coking plants accounted for 88.46%-90.38% (Beijing), 83.56%-98.17% (Chongqing) and 74.56%-92.96% (Taiyuan), respectively. The PAHs pollution sources in the soil of the coking plants still exist and include a small part of oil spills and burning. Among the three sites, the maximum proportions of 8 kinds of pollutants, which exceeded the national first-class and second-class control values, are 8.23% and 5.18% (Beijing), 15.34% and 9.77% (Chongqing), and 13.72% and 8.68% (Taiyuan). In addition, the risk levels of the eight PAHs in Beijing and Chongqing were higher than that in Taiyuan. In summary, the results illustrate that the soil of the former coking plants still have high concentration of PAHs in the depth range of 0-20 m. The pollution characteristics of PAHs in the soil of coking plant sites were closely related to the locations and formation conditions. Formation conditions may largely affect the distribution and migration of PAHs in the soil, and the impact on high-ring PAHs were smaller. The results of the study may provide basis for soil remediation and environmental risk assessment of other coke-industry contaminated sites.

In order to understand the contamination characteristics and bioavailability of heavy metals in the areas with abundant phosphate ore mines, the concentrations of Cd, Cu, Pb and Zn in samples of farmland soils and samples of different crops such as maize, rice and vegetables collected from Yunnan and Guizhou phosphate ore mine areas were determined and then the pollution characteristics of soils were evaluated. The regression equations were used to explore the effect of available heavy metals and soil properties on the quality of the agricultural products. The results show that Pb and Cd were enriched in most soil samples, the average enrichment factors of Cd and Pb reached to 2.31 and 2.39, respectively, compared to the local background values. About 84.8% and 28.3% of soil samples were polluted by Cd and Pb, respectively, and Pb concentrations were markedly higher than that of the farmland soils of other geological high background areas. The average biological accumulation factors of Cd in maize, rice and leaf vegetables were 0.09, 0.17 and 0.32, respectively. The soil Pb bioavailability in the studied area was lower than those in other high background areas. The crops had different abilities to absorb heavy metals, and the Chinese cabbage had the largest absorbing ability to four heavy metals and the absorbing ability of rice to Cd and Pb were higher than those of maize. It is not advised to plant Chinese cabbage in those areas, and the risks of Cd and Pb that exceeding the safety limits in crops should be considered. Correlation analysis and regression equations show that available heavy metals, along with pH, organic matters, and MgO in soils were the key factors affecting the accumulation of heavy metals in crops (P<0.05).

In order to explore the bioavailability of heavy metals in farmland soil near a uranium mining area, the samples of farmland soil near mining area, smelter and tailings dam were collected as the research object to analyze the physical and chemical properties of the soil and the improved BCR four-step extraction method was applied to evaluate the bioavailability of the heavy metals (Pb, Cd, Cr, Cu) and U in the farmland soil. The results show that the farmland soil in the study area is acidic; the organic matter content of the farmland soil in different locations followed the order of: tailing dam > smelter > mining area; The forms of heavy metals in the farmland soil are dominated by the residue state; The content of bioavailable form of the heavy metal elements (Pb, Cd, Cr and Cu) accounted for 27%-42% of the total content of heavy metals, and the content of bioavailable form of radionuclide U was 43%-45% of the total content of U; the enrichment coefficients of heavy metals (Cr, Cd, Cu and Pb) for crops grown at different locations followed the order of: mining area > smelter > tailing dam; Compared with the adsorption of the other heavy metals, the adsorption of U by crops in all locations was the strongest. In summary, the bioavailability of heavy metals in farmland soil is comprehensively affected by factors such as pH, organic matter content, and bioavailable content of heavy metals. The stronger the bioavailability of heavy metals, the greater the ecological risk they cause; The bioavailability of the heavy metals (Cr, Cd, Cu, and Pb) in farmland soil of different locations followed the order of: mining area > smelter > tailing dam; U had the strongest bioavailability in farmland soils of different locations; due to the influence of uranium ore extraction, U in the smelter had a higher bioavailability than in other study areas. Though, the crops in the tailings dam farmland have poor enrichment effect on heavy metal elements, while considering the high content of heavy metals in the soil of this location, the ecological risks brought by it are also worthy of attention. The research results can provide an important theoretical basis for the scientific and biological control of heavy metal pollution in mining areas in the future.

To clarify the characteristics and influencing factors of gaseous nitrogen (N₂O and NH₃) loss in peanut field on red soil arid hillside, aeration method and closed static opaque chamber-gas chromatography (GC) methods were adopted. In situ monitoring was carried out to reveal the dynamic change characteristics of NH₃ volatilization and N₂O emission of the peanut field on red soil arid hillside under conditions of plowing and no-tillage. Their key influencing factors were identified based on boosted regression tree (BRT) method. The results show that: (1) The variation range of NH₃ volatilization rate (measured in N) during the whole peanut growth period under plowing and no-tillage conditions was 0.02-1.55 and 0.02-1.05 kg·hm^-2·d^-1, respectively, the cumulative volatilization was (17.19±8.56) and (18.38±7.41) kg·hm^-2, respectively, accounted for (11.77±5.86)% and (12.59±5.08)% of the N application, respectively, and the NH₃ volatilization was concentrated within 15 d after base fertilizer application. The variation range of N₂O emission flux under plowing and no-tillage conditions was 0.07-2.90 and 0.02-3.97 mg·m^-2·d^-1, respectively, the cumulative emission was (0.81±0.27) and (0.68±0.10) kg·hm^-2, respectively, accounted for (0.55±0.17)% and (0.46±0.06)% of the N application, respectively, and the hot period of N₂O emission flux was not obvious. No significant difference in NH₃ volatilization between two tillage treatments were found, while no-tillage reduced cumulative N₂O emission by 16.05%. Ammonia volatilization was the main way of nitrogen gas loss in peanut field of red soil arid hillside. (2) The BRT analysis findings, soil ammonium-nitrogen content, days after fertilization, peanut growth period, rainfall in the previous 3 days, soil nitrate-nitrogen content were identified as the key factors affecting ammonia volatilization of the peanut filed on red soil arid hillside. The contribution rates were 47.92%, 14.78%, 8.21%, 7.44% and 5.91%, respectively. However, the key influencing factors of N₂O emission and their relative contributions were soil moisture (24.67%), soil ammonium-nitrogen content (20.34%), ground temperature (12.26%), rainfall in the previous 3 days (9.93%), soil nitrate-nitrogen content (9.91%), days after fertilization (9.64%), and temperature (8.51%). The above results show that fertilization is an important factor affecting the gaseous loss of nitrogen fertilizer in peanut field of red soil, and the highest loss of gaseous nitrogen (NH₃ and N₂O) accounted for 18.35% of the N applied. Microbial nitrification process and its environmental control factors may play an important role in soil nitrogen loss. These results could provide a theoretical basis for improving nitrogen utilization rate and mitigating environmental pollution in hillside agriculture in red soil region of South China.

The effects of the integrated rice-crayfish farming on rice quality and its nitrogen (N) accumulation were studied in Tongling City, Anhui Province to provide a scientific basis for nitrogen management in the integrated rice-crayfish farming system. A field experiment was conducted to compare nitrogen uptake and accumulation of rice in the integrated rice-crayfish farming system with feed (RCF) and without feed (RC), with the rice monoculture only (R) as control. The yield and quality of rice in different farming systems were compared. The N input-output balance in different farming systems was also calculated. The results indicate that rice tissues under RC treatments had higher content of N than that of R at the mature stage (P<0.05). Likewise, RCF and RC treatments led to significantly higher N accumulation in rice tissues compared with R (P<0.05). Their nitrogen accumulation increased by 20.9% (RCF) and 26.9% (RC), respectively. No significant differences were found in the N content and accumulation of rice between RCF and RC treatments. Compared with R, the milled rice rate and protein content of grain under RC treatment increased by 3.0% and 8.4%, respectively. Conversely, chalky rice rate, amylose content, and gel consistency of rice reduced by 25.1%, 7.5%, and 6.6%, respectively, in RC treatment compared with R. However, RCF and RC treatments caused significantly higher N output from rice and straw than R (P<0.05). The N utilization efficiency of R, RCF, and RC were 0.85, 0.98, and 1.11, respectively. Altogether, the results of this study suggest that RCF and RC could promote N accumulation in rice, and increase rice quality and N utilization efficiency, whereas there exists a risk of consuming soil nitrogen. Nevertheless, no significant differences occurred in rice N utilization and rice yield between RC and RCF treatments. From the view of economic and environmental benefits, the integrated rice-crayfish farming system with appropriate feed is a high-efficient farming system to achieve sustainable development in this region.

The red-crowned crane (Grus japonensis) is a first-class national protected animal in China and has already been listed as an endangered species on the International Union for Conservation of Nature (IUCN) red list. In this study, the quantitative change and distribution status of captive red-crowned crane population in the recent years was first analysed using the data on the number of captive red-crowned cranes in ex-situ and in-situ protecting institutions. The relationship between captive and wild populations of red-crowned cranes, as well as the advantages and disadvantages of zoos (cage zoos, semi-open zoos, and open zoos) and nature reserves in protecting the red-crowned crane, was discussed. Finally, some suggestions on the captivity management of the red-crowned crane were put forward. As of December 2019, a total of 182 protecting institutions (157 zoos and 25 nature reserves) have been investigated in mainland China; 90 of these institutions had red-crowned cranes in captivity, with a total of 2 386 captive red-crowned cranes (1 176 in the zoos and 1 210 in the nature reserves) distributed in 28 autonomous regions, provinces, or municipalities of China. The average number of red-crowned cranes was significantly lower in cage zoos than in semi-open zoos (P<0.05) and in semi-open zoos than in open zoos (P<0.05). Overall, the average number of red-crowned cranes was significantly lower in zoos than in nature reserves (P<0.05). The facilities in the cage zoos are simple; in these zoos, red-crowned cranes are mostly used to attract tourists. However, this is not favourable for the protection of red-crowned cranes, and the semi-open zoos are also unable to carry out high-quality management of a large number of captive red-crowned cranes. On the contrary, the large sizes of open zoos and nature reserves and the domestication conditions of red-crowned cranes are conducive to the protection of captive red-crowned cranes. The wild population of the red-crowned cranes in China can be increased by domesticating and releasing the captive-bred population. Therefore, first, it is suggested that the red-crowned cranes in the cage zoos with poor feeding conditions should be introduced or incorporated into large zoos. Second, the feeding mode of captive red-crowned cranes should be changed into the free-range feeding type. Finally, it is also necessary to improve the feeding environment of young cranes and raise them separately.

Lake Taihu is the third largest freshwater lake in China. The fish community and the correlations between the fish species and environmental factors were investigated from 2018 to 2020. Customized gillnets and fixed cages were arranged to conduct 40 sampling events at the 24 sampling points in different regions of the lake. Taxonomic identification of the 4 160 specimens revealed that all the bony fishes, belong to 6 orders, 11 families, 37 genera, and 52 species. Coilia nasus (specifically a geographical/ecological population formerly recognized as Coilia ectenes taihuensis) dominated in numbers, and Cyprinus carpio dominated by weight. The lake's fish community is characterized by a dominance of small-sized surface-dwelling fishes and a decreasing proportion of carnivorous fishes. Cluster analysis of the fish community data (Ward's minimum-variance method) showed different assemblages in the northwestern and southeastern areas of the lake. Canonical correspondence analysis of environmental variables in relation to the fish community data found that water clarity (SD), pH, a fish-based index of biotic integrity (F-IBI), water temperature, and the chemical oxygen demand based on potassium permanganate (COD_Mn) were key factors. COD_Mn was the main environmental factor affecting several of the predatory and omnivorous species. Hemiculter leucisculus and Culter alburnus were mainly influenced by SD; Tachysurus fulvidraco by pH; and Sarcocheilichthys nigripinnis by F-IBI. On the basis of the present aquatic environment and the existing methods for biomanipulation of fish communities, management efforts to increase the carnivorous fish such as the species of Culter and Cultrichthys would reduce the dominance of Coilia nasus, thereby expanding the zooplankton population available to suppress planktonic algae.