Amphibians are a crucial component of global biodiversity, yet they are experiencing rapid population declines worldwide. The primary objectives are to evaluate the feasibility of using eDNA as a non-invasive method for surveying amphibian diversity in Chaohu Lake basin, to analyze the community characteristics of amphibians across different habitats, and to explore the key factors influencing amphibian diversity and distribution patterns in the region. This study employed environmental DNA (eDNA) combined with traditional line transect method (TLTM) to conduct a comprehensive assessment of amphibian diversity within Chaohu Lake basin protected area in four different habitats of river, wetland, cropland, and pond. Across the 40 survey sites, a total of 9 amphibian species were detected by both methods, with the eDNA method identifying significantly higher amphibian richness than the TLTM. Species richness in river habitats was significantly lower than in pond and wetland habitats, while species richness in cropland habitats showed no significant difference from the other three habitats. The Fejervarya multistriata exhibited a consistent advantage across all habitats, while the Rana zhenhaiensis, and Rana culaiensis, showed a preference for pond habitats, and Bufo gargarizans was more frequently found in river habitats. During autumn, the results obtained from both methods were comparable across the four habitat types, whereas in spring, the eDNA method demonstrated superior performance to TLTM. Amphibian species richness and abundance were higher in spring compared to autumn. Water width significantly influenced amphibian distribution both in spring and autumn, with additional impacts from water temperature and pH in spring. This study underscores the differences in community structure and dominant species across the four habitat types, revealing that amphibian diversity and distribution patterns are shaped by multiple environmental factors. The findings confirm that eDNA is an effective method for surveying amphibian diversity in Chaohu Lake basin.

Interactions between hydrology and microtopography are a key factor shaping habitat heterogeneity in lakeshore zones, yet their synergistic effects on the Chaohu lakeshore plant communities remain unclear. Here, we addressed this issue by delineating four flooding zones along an elevation gradient and selecting four microtopographic types: Estuarine Zone, Sheltered Cove, Windward Upland, and Terraced Wave-Breaker to explore how their combined effects shape community structure and diversity. We conducted systematic field vegetation surveys and soil physicochemical measurements, and employed non-metric multidimensional scaling, two-way permutational multivariate analysis of variance, and redundancy analysis to quantify the individual and interactive effects of hydrology and microtopography on plant community composition and species diversity. Results showed that: (1) Hydrology predominantly shaped plant community differentiation along the elevation gradient, with composition transitioning from hygrophytes and hydrophytes to meso-xerophytes as flooding decreased; (2) The ecological effect of microtopography varied with hydrological conditions—masked by strong hydrological filtering in long-term flooded areas, it drove further differentiation by regulating local conditions as flooding stress weakened; (3) Species diversity was jointly regulated by both factors, with richness peaking in the short-term flooding zone and the Estuarine Zone hosting the highest species diversity. This study clarifies plant community assembly under anthropogenic disturbance, highlighting the synergy between hydrology and microtopography as key to understanding regional biodiversity patterns, and offering a basis for lakeshore restoration through integrated hydrological and microtopographic management.

Waterbirds are strongly dependent on wetlands during breeding and wintering stages, yet the mechanisms by which seasonal water-level fluctuations (WLF) in gate-controlled lakes shape waterbird communities across life-history stages remain unclear.To address this, we selected five restored wetlands in the Chaohu lakeshore zone and integrated field surveys, remote sensing, and multivariate analyses to explore how WLF influences waterbird community composition and functional diversity across breeding, early and late wintering stages. During the breeding and early wintering periods, waterbird community composition showed significant differences, whereas no significant differences were observed during the late wintering period. The proportion of mudflat area was the dominant environmental variable across all periods. During the late wintering period, functional richness and functional divergence were highest, whereas turnover and total dissimilarity were lowest. Wintering waterbird functional diversity was primarily driven by submerged plant biomass and floating-leaved plant coverage. Maintaining appropriate proportions of habitat areas promotes high-density aggregation of different foraging functional groups. Aquatic plants >20% supports aquatic plant feeders (G1; optimal water level: 8.90 m), water 0–20% supports shallow water piscivores (G3; 8.62 m), while mudflats ∼75% support invertebrate feeders (G5; 8.68 m). This study highlights the importance of water-level regulation, habitat structure optimization, and disturbance management for conservation of waterbirds across life-history stages, providing a scientific basis for adaptive water level management and wetland restoration in gate-controlled lakes.

Lakeside wetlands play a critical role in mitigating non-point source nitrogen (N) pollution, yet the mechanisms underlying vertical microbial stratification across the water-sediment interface remain unclear. Based on a single dry-season sampling campaign conducted in February 2023, microbial communities and N-cycling functional genera exhibited a clear depth-dependent stratification under hydrological fluctuation, but their responses were not vertically synchronized. The sediment profile functioned as a three-tier system, shifting from disturbance-buffered surface processes to subsurface-dominated regulation: weak soil-microbe coupling in surface layers (0-10 cm), coupling between soil and microbial indicators strengthened at intermediate depths (10-40 cm), and soil-mediated control became more evident in the lower-profile layer (40-50 cm). Environmental effects emerged at 20-30 cm, whereas microbial network connectivity peaked at 30-40 cm, suggesting a delayed and partially dissociated relationship. Denitrifying taxa showed a weak V-shaped depth distribution, with the highest relative abundance in the top 5 cm (32.5% ± 17.0%) and a minimum at 10-20 cm (23.8% ± 14.1%). Soil parameters explained most of the community variation, while vegetation and hydrological factors contributed less. These findings identified the intermediate layer (10-40 cm) as a critical functional zone for N transformation, while the lower-profile layer (40-50 cm) may retain residual denitrification-related potential under resource-limited conditions. These findings suggested that subsurface soil-microbe interactions should be considered when evaluating dry-season N-cycling potential in the lakeside wetlands, although their temporal stability and actual functional activity require further verification.

Wind-induced circulation is the main form of lake flow for shallow lakes and plays an important role in algae population distribution. This study constructed a three-dimensional hydrodynamic model (EFDC) of the plateau lake Erhai, China using accuracy wind field observation, runoff data and monthly algae data during 2022-2023. The model successfully reproduced the circulation characteristics of Erhai under prevailing wind directions. The results showed that the lake flow velocity in Lake Erhai is higher in winter than in summer, with lower velocities near shore particularly in the northern and central parts of the lake. There is a negative correlation between algal biomass and flow velocity (FV) in different zones, with lower FV favoring the accumulation of algal biomass, particularly for Microcystis, Dolichospermum, and Peridinium. Additionally, due to buoyancy, cyanobacteria are highly affected by wind direction and tend to accumulate in downwind regions of the prevailing wind direction. This study demonstrates that wind-induced circulation is a crucial factor affecting the spatial distribution of dominant algae populations in shallow plateau lakes with weak hydrodynamic force. Further, the risk of bloom occurrence in Lake Erhai will be higher due to the background of global climate change and the lake's wind speed decline. In conclusion, we suggest implementing targeted zoning measures to control algal blooms and establishing stricter regulations for nitrogen and phosphorus control to counterbalance the promotion of algal bloom accumulation in low-velocity zones caused by reduced wind speed.

Algae play an important role in lake ecosystems, and algal succession is vital to studying the mechanism of algal bloom outbreaks. This paper provides a comprehensive review of algae blooms development, bloom-forming algae succession, the diversity of common blooms-forming algae, and key drivers for algae succession in Chinese lakes, based on an extensive literature survey and data sets. Furthermore, it summarizes the influencing factors for algae blooms and bloom-forming algae succession in five lake zones of China. The results indicated that the number of research publications on algal blooms in China constituted the largest share of global research, representing 41.9 %. The predominant types of algae blooms in all publications were cyanobacterial blooms, followed by dinoflagellate blooms. The blooms-forming algae in China's lakes have experienced a clear succession pattern: Bacillariophyta, Chlorophyta and Pyrrophyta were dominated in the initial investigations; dominance of Microcystis, Anabaena, dinoflagellates and diatoms increased significantly since1960s; in the past decade, Cylindrospermopsis and dinoflagellates expanded. Current research on algae blooms in Chinese lakes mainly focuses on cyanobacterial blooms, especially Microcystis blooms, while researches on filamentous cyanobacterial blooms and other algae blooms is still insufficient. This systematic review will help researchers to understand the basic features such as the occurrence, the diversity, the physio-ecology and the driving factors of common blooms-forming algae, will further provide a scientific basis for their control in various lake regions.

Many lakes worldwide, including in China’s Yangtze River Basin, face eutrophication, which reduces phytoplankton diversity and increases bloom risk. Following severe pollution, these Chinese lakes have undergone substantial control and regulation. However, the efficacy of these measures is still unclear. Focusing on Lake Chaohu as a representative case, this study investigated the seasonal phytoplankton dynamics (2022–2023) under concurrent nutrient reduction and a fishing ban. The annual mean concentrations of total nitrogen, total phosphorus, and chlorophyll a were 1.57 mg/L, 0.184 mg/L, and 21.21 μg/L, respectively. The phytoplankton community was dominated by Cyanobacteria, which constituted approximately 75% of the total biomass. Co-occurrence network analysis revealed lower community stability during these warm, Cyanobacteria-dominated periods. Statistical analyses identified total phosphorus and temperature as key drivers, confirming bottom-up control via nutrient limitation as the fundamental mechanism. However, extreme heat events may have partly offset the benefits of nutrient reduction by promoting cyanobacterial dominance, which can decrease phytoplankton diversity. A recorded decrease in phytoplankton phosphorus use efficiency after the fishing ban suggests a potential strengthening of top-down control. These findings highlight that sustained nutrient load reduction is essential to reduce cyanobacterial bloom risk, while continued enforcement of the fishing ban may enhance the regulatory effect of top-down control on cyanobacterial blooms, thereby improving the stability and diversity of phytoplankton communities.

Dissolved organic matter (DOM) characteristics and concentrations in lakes are strongly associated with terrestrial input, phytoplankton dynamics, and physicochemical environment. Hydrological conditions can affect multiple aspects of the lake environment, thereby interfering with DOM cycling. This study investigates the long-term trends and drivers of DOM accumulation in Lake Erhai, a subtropical plateau lake in southwestern China, focusing on the role of hydrological processes in driving its accumulation and persistence. By analyzing data from 1992 to 2023-including bulk chemical analysis, 3D-EEM fluorescence spectroscopy, degradation experiments and bayesian structural equation modeling (BSEM), it is concluded that a 174 % increase in water residence time (WRT), from 2.8 years to 7.8 years, driven by reduced inflow and outflow volumes, has promoted the accumulation of refractory DOM (RDOM), raising chemical oxygen demand (CODMn) and presenting substantial challenges challenges to water quality management. Degradation experiments revealed limited biodegradability of DOM (15 % over 28 days) and minimal photodegradation (13.5 % over 72 h), with more than 80 % remaining in a refractory state. Spectroscopic analyses revealed compositional shifts in DOM with prolonged WRT, characterized by decreased humic-like substances and increased protein-like compounds, indicating a progressive transition from allochthonous to autochthonous DOM dominance. BSEM analysis identified a significant temporal shift in DOM drivers: during the initial phase (1992-2010), human activity pressure (HAP) and riverine input quality (RIQ) collectively explained 70 % of the variance, with natural drivers contributing less than 20 %; whereas in the subsequent phase (2010-2023), anthropogenic influences diminished as hydrological and climatic factors became predominant, with hydrological regime (HR) and climatic factors (CF) jointly accounting for 87 % of RDOM variance, reflecting a transition from anthropogenic to climate-hydrological driven accumulation patterns. This research underscores the critical role of hydrological residence time in determining DOM composition, sources, and persistence in plateau lakes following partial decoupling of external pollution sources. The findings highlight the dual influence of climate and hydrology on lakes experiencing significant pressures from reduced water resources and increasing water demand, challenging conventional management strategies focused exclusively on external nutrient control. The case of Lake Erhai demonstrates the necessity for integrated management approaches that address both external and internal DOM dynamics to support sustainable water quality and ecosystem integrity.

The linkages of distributed ponds are utilized in conjunction with one another to remediate non-point source (NPS) pollution in a water-scarce basin. This study provides an overview of a state-of-the-art thorough evaluation of ponds, which offers insight into the majority of topics covered by the ongoing scientific studies, including their various functions and factors affecting their functioning on the hydrological, physicochemical, and biological processes, such as environmental climate factors and basin-specific landscape configuration parameters, as well as process parameters for design, operation and management aspects. The linkages of ponds provide a variety of sustainable services (6R functions), such as resources, restoration, reduction, reuse, recycling, and recovery. The significance of regional environmental geochemical substrates in the ponds, such as red soil, as a hotspot for microbial reaction is emphasized to demonstrate the significant contribution of the migration and transformation of Fe/N cycles to the pollution removal process. In this review, 178 original research publications were thoroughly analyzed to improve our knowledge of the iron-nitrogen cycle in wetlands. From a molecular biology standpoint, the identification of functional microbe species and genes linked to microbially driven iron-nitrogen cycle activities is delved. Reliable data and homogeneous datasets from 42 studies were collected. The correlation analysis results demonstrated Feammox rates contributed to the N loss amount (r = 0.871; p < 0.01), and they had a positive correlation with Fe(III) concentration (r = 0.965; p < 0.01). The proposal for the treatment of NPS pollution by large-scale linkages of ponds in a basin involves optimizing Fe/N microbial processes to promote iron crystallization and efficient circulation of Fe(II) and Fe(III). The co-benefits of geochemistry, biotechnology, and environmental science should be considered when managing contamination in engineering applications. The linkages framework for integrated ponds, which incorporates macro (watershed management) and micro (biogeochemical cycle mechanism) investigations, provides a systematic approach to the application of integrated ponds and sustainable water management for NPS pollution control.

Background:Niche partition and traits tradeoff theory were primary strategies for plants coexistence. However, specific strategies of plants remained to be verified to guide community configuration and biodiversity maintenance in ecological restoration. Methods:The variation of plants composition and niche breath were utilized to examine the temporal and spatial niche partition strategies, respectively. Meanwhile, the chi-square (χ2), Spearman rank correlation coefficient (rij), Ochiai index (OI) were employed to analyze the interspecific relationship of 30 predominant species from species pool of 220 vascular plants. Besides, the Lotka-Volterra model was utilized to reveal the traits tradeoff strategies of predominant species from five vegetation formations. Results:About 62.41% pairs of wetland species were niche partitioned while 37.58% of species pairs were niche overlapped. In temporal scale, 60.5% of species occurred either in spring or autumn while 39.5% occurred in both seasons. Meanwhile, significant change of relative height (RH) and relative coverage (RC) were observed in constructive species and auxiliary species. Height tradeoff strategy ( Δ R H Δ R C > 1 ), coverage enlarge strategy ( Δ R H Δ R C < 1 ), or both strategies ( Δ R H Δ R C = 1 ) observed in wetland plants. Discussion:Our finding testified that the temporal niche partition and traits tradeoff strategies are objectively observable in wetland plants. These findings on coexistence strategies can be used in the configuration of plants communities and the biological control of alien invasive plants.

The littoral width of lakeshores is crucial for maintaining and promoting plant diversity. However, it remains unclear how changes in seasonal water level affect littoral widths by regulating plant diversity and soil nutrient content. This study selected three elevation ranges in the lakeshore of Erhai: supralittoral, eulittoral, and infralittoral. We explored the effects of hydrological changes on littoral widths and their potential relationships by analyzing seasonal differences in plant communities and soil physicochemical properties during an extremely drought year. Our results indicated that the most significant seasonal differences in diversity indices, biomass, and soil physicochemical properties were observed in the eulittoral, followed by the infralittoral and supralittoral. The niche breadths of perennials was significantly decreased by 44.4% and the width of the eulittoral was significantly decreased by 48.6% during the winter. Generalized Additive Models (GAMs) were applied to analyze the elevation distribution ranges of dominant species. The results revealed that species with monotonically increasing distributions had the widest niche breadths, followed by symmetric unimodal species, while monotonically decreasing species exhibited the narrowest. Structural equation modeling revealed a positive and significant correlation between flooding days and soil water content and pH, and a negative correlation with plant parameters (species number, biomass, and coverage). Moreover, plant parameters showed a significant positive correlation with plant diversity. Importantly, plant diversity and soil nutrients were significantly positively correlated with littoral widths, suggesting their key roles in influencing littoral widths. This study highlights the significant impact of hydrological seasonal changes on the littoral widths of lakeshore zones, providing valuable guidance for managing wetland water levels in response to extreme drought events.

The relationship between wetland water level changes and plant community has been a research hotspot. However, the gradient changes and critical influencing factors of plateau lakeshore plants and soils during wet-dry alternation remain unclear. Here, we studied the variations in plants and soils along the Erhai lakeshore across three elevation ranges (1965.0-1965.3m, 1965.3-1965.6m, and 1965.6-1966.4m) during flooding and drought years. Our research aimed to elucidate the interrelationships and mechanisms among hydrology, soil properties, and plant dynamics. The results showed that (1) In drought years, the Shannon-Wiener index of plants significantly decreased across the three elevation ranges, and other plant diversity indices, biomass, and coverage also decreased to varying degrees; (2) except for soil pH, soil water (SW) and nutrient content decreased to varying degrees in the drought year; (3) SW was the primary factor influencing plant biomass, coverage, and diversity in the 1965.0-1965.3m and 1965.3-1965.6m ranges; nitrate nitrogen, C/N ratio, total phosphorus were the primary factors in the 1965.6-1966.4m ranges. The results of structural equation modeling revealed a significant and strong correlation between SW and plant biomass, coverage, and soil pH. This suggests that changes in SW directly impacted plant biomass accumulation, subsequently affecting coverage, and also played a role in regulating soil pH. This study identified the effects of hydrological inter-annual changes on plant communities and highlighted SW as a crucial driver. The strategies proposed in the results protect and improve the diversity and stability of lake ecosystems in Lake Erhai and other similar lakes.

The coexisting strategies of plants under interspecific competition driven the trajectory of succession which concerned the ecological success of biodiversity maintenance in restored or created wetlands. To reveal the coexisting mechanism and guide the management of vegetation recovery, 220 vascular plants from 19 restored lakeside wetlands were systematically analyzed. The Ochiai index (OI) indicated that 62.41% of 435 pairs species exhibited negative correlation compared with 37.58% of positive correlation. The coexistence of heterospecific species was mainly accomplished via spatial and temporal niche partitioning, as well as trade-offs in height and coverage of plants. In terms of spatial niche partition, emergent plants were found to have a wider niche breadth of 1.67 ± 0.60 compared to upland plants with 1.28 ± 0.36. In temporal, 33.6% of species occurred in spring, 26.8% in autumn, and 39.5% in both seasons. Furthermore, according to plants phenology, the species maturing in spring, summer, and autumn accounted for 8.18%, 25.45%, and 62.27%, respectively. These findings on coexistence strategies can be used in the configuration of plants communities in both restored and created wetlands.

Initial flush management is an effective measure to control non-point source pollution (NPSP) in storm runoff. However, determining the parameter of the initial flush in different areas may pose challenges in storm runoff management strategies. To address this issue, Erhai Lake in China, Yunnan-Guizhou Plateau, was selected as an example for the study. Erhai Lake is a typical mesotrophic lake with the profound influence of NPSP. The NPSP control strategy in this area will provide a valuable reference for other lakes. In 2021, 289 storm events and 190 ditchwater samples were detected around Erhai Lake. The average flow in the ditches ranged from 0.004 to 0.147 m3/s, the instant total nitrogen (TN) concentration ranged from 0.28 to 91.43 mg/L, and the instant total phosphorus (TP) concentration ranged from 0.26 to 7.35 mg/L in the storm events. It was found that the concentration of pollutants was lower than expected in the initial flush period. Instead, the event mean concentrations of TN and TP were 9.3 and 2.1 times higher than in the wet seasons, showing high nutrient concentration levels throughout the entire rainfall period. To manage storm runoff effectively, a flow-processes-division method was proposed to analyze the inflow condition and pollutant removal rate in different runoff periods. The peak flow interception strategy was recommended as the optimal stormwater management plan, as it showed the highest inflow conditions and 50% pollutant removal rate. Considering the need to reduce the constant flush of stormwater runoff, it is essential to establish a healthy water cycle system to alleviate NPSP and raise the Erhai water level. The storm runoff management method can serve as a practical tool for lake areas that do not exhibit initial flush characteristics.

Extreme weather events caused by climate change have a significant impact on the lake ecosystems. While many researchers believe that heatwaves and droughts may enhance algal bloom, heatwaves and droughts reduced algal blooms in Lake Chaohu during the spring and summer of 2022. To investigate the mechanism behind this phenomenon, on-site sampling and online monitoring were conducted in Lake Chaohu from 2019 to 2022. The results showed that non-algal turbidity played a critical role in temporarily inhibiting algal blooms. The water level in spring and summer of the drought year was 1.2 m lower than that in conventional years, resulting in the area of shoals where resuspension could occur being nearly 4 times larger than in conventional years. Strong resuspension caused turbidity in spring and summer to be more than double that of conventional years, sharply reducing gross primary productivity by 39 %, which led to lower chlorophyll a concentration than in conventional years. These results indicate that drought does not necessarily exacerbate algal blooms, and changes in shoal area due to water level fluctuations are a key factor affecting algal blooms in shallow lakes prone to resuspension. Furthermore, these results suggest lake managers can control algal blooms by adjusting water level to increase turbidity during or before algal bloom seasons.

Algal blooms in lakes have been a challenging environmental issue globally under the dual influence of human activity and climate change. Considerable progress has been made in the study of phytoplankton dynamics in lakes; The long-term in situ evolution of dominant bloom -forming cyanobacteria in meso-eutrophic plateau lakes, however, lacks systematic research. Here, the monthly parameters from 12 sampling sites during the period of 1997 - 2022 were utilized to investigate the underlying mechanisms driving the superiority of bloom -forming cyanobacteria in Erhai, a representative meso-eutrophic plateau lake. The findings indicate that global warming will intensify the risk of cynaobacteria blooms, prolong Microcystis blooms in autumn to winter or even into the following year, and increase the superiority of filamentous Planktothrix and Cylindrospermum in summer and autumn. High RUE TN (1.52 Biomass/TN, 0.95 - 3.04 times higher than other species) under N limitation (TN < 0.5 mg/L, TN/TP < 22.6) in the meso-eutrophic Lake Erhai facilitates the superiority of Dolichospermum . High RUE TP (43.8 Biomass/TP, 2.1 - 10.2 times higher than others) in TP of 0.03 - 0.05 mg/L promotes the superiority

The lake littoral zone is periodically exposed to water due to water level fluctuations, driving the succession and distribution of littoral vegetation covers, which complexly affect nutrient biogeochemical transformation. However, the combined effects of water level fluctuations and other environmental factors on microbial characteristics and functions at the regional scale remain unclear. In this study, typical vegetation cover types along various water levels were chosen to investigate the effects of water level and vegetation cover on the microbial community and functional genes in the Lake Erhai littoral zone. The results showed that water level fluctuations influenced oxygen and nitrogen compound contents due to oxic–anoxic alternations and intensive material exchange. Meanwhile, vegetation cover affected the organic matter and total nitrogen content through plant residues and root exudation supplying exogenous carbon and nitrogen. Along the hydrological gradient, the high microbial diversity and abundant microbes related to nitrogen cycling were observed in interface sediments. It was attributed to the alternating aerobic–anaerobic environments, which filtered adaptable dominant phyla and genera. The abundances of amoA AOA, nirS, and amx were higher than those of the other genes and were strongly related to flooding days and water content. In conclusion, water level fluctuations and vegetation type jointly affect microbial community structure and nitrogen-related functional genes.

Dissolved organic matter (DOM) is one of the important components in lake sediment. Identifying the composition and sources of sediment DOM exerts great significance on the understanding of carbon biogeochemical processes and the eutrophication control of lake. To trace the source of sediment DOM in Lake Kulipao, samples of sediment and potential sources were collected in May and August 2021, including surface and core sediment samples, phytoplankton, macrophytes, C3 and C4 plants, livestock manure and treated effluent. Stable isotope (δ13C and δ15N) and fluorescence spectroscopy were applied to characterize the DOM composition of sediment and source samples. Furthermore, contribution rates of different sources to surface and core sediment DOM were calculated using IsoSource software. The calculation results showed that: (1) δ13C and δ15N of DOM in surface sediment differed in May (average values of -25.54‰ and 9.02‰) and August (average values of -26.81‰ and 8.40‰). (2) δ13C and δ15N of DOM in core sediment differed in depth, with average values of -26.58‰ and 9.04‰ in depth of 0-3 cm and -25.40‰ and 10.61‰ in depth of 3-30 cm. (3) Fluorescence components of surface sediment DOM were dominated by humic-like component (87.89%) in May, with HIX and BIX values of 6.27 and 0.67. In August, protein-like component increased to 49.58% with HIX and BIX values of 1.72 and 0.87. (4) Source analysis showed that allochthonous DOM (61%) dominated in surface sediment in May, with soil and treated effluent proportions of 21.40% and 18.08%, respectively. In August, proportion of autochthonous DOM increased to 55.10%, with a high contribution of emergent macrophyte (48.68%). (5) The DOM sources of core sediment showed no significant variation with depth, with treated effluent, submerged plant/algae and emergent macrophyte dominating the DOM with proportions of 42.13%, 25.07% and 18.53%, respectively. In a whole, sources of sediment DOM in Lake Kulipao were mainly related to the human activities and climate features. This study can potentially improve the understanding of DOM accumulation and transportation in northeast watersheds of China.