Momoge Wetland Research Articles

Disturbance alters soil organic carbon content and stability in Carex tussock wetland, Northeast China

With the intensification of climate change and human activities, wetland ecosystem and their carbon pool function have been seriously compromised. To determine the soil organic carbon pool composition and stability response to wetland disturbance, three disturbed (grazing, mowing, invasion) and two undisturbed Carex tussock wetlands were investigated in Momoge Wetland, northeast China. The results showed that the disturbance significantly reduced the soil organic carbon content under hummock, but effectively promoted organic carbon storage in surface soil in hummock interspace. In disturbed wetlands, relative abundance of aromatic-C, asymmetric aliphatic-C, polysaccharide-C and clay minerals, and organic carbon stability significantly declined. Furthermore, asymmetric aliphatic-C and polysaccharide-C were the most important organic carbon chemical components affecting SOC stability under hummock and in hummock interspace. Disturbance facilitated the effects of pH, TP and minerals on organic carbon stability, with pH being the most important. These findings improved our understanding of the composition and stability of carbon pools in disturbed wetlands.

Research on the Transformation Mechanism of Soil Cadmium Fractions under the Conditions of Freeze-thaw and Crude Oil Contamination in Wetlands in the Songnen Plain, China

Environmental changes can significantly affect heavy metals behave in soil. Currently, we know little about the impact of crude oil contamination on heavy metal fractions in soil, with few studies available on heavy metal fraction transformation under the composite action of freeze-thaw and crude oil contamination. In this study, soil samples were collected from the Momoge Wetland in the Songnen Plain. Properties including pH, cation exchange capacity, calcium carbonate, free iron oxide, dissolved organic carbon, microbial biomass carbon, and cadmium (Cd) fractions under freeze-thaw, crude oil contamination, and the two combined (composite action) were analysed. The results show that under freeze-thaw, crude oil contamination, and composite action, soil properties changed significantly; soil water-soluble Cd content significantly increased by 54.17%, 62.50%, and 33.33% from control levels, respectively; soil ion-exchangeable Cd content decreased significantly by 10.90%, 23.73%, and 18.64% from control levels, respectively; soil residual Cd content significantly increased by 80.36%, 94.64%, and 132.14% from control levels, respectively; carbonate-bound, humic acid-bound, Fe-Mn oxide-bound, and strongly organic-bound Cd did not change significantly. Soil dissolved organic carbon, pH, CaCO3, and free iron oxide were significantly correlated with water-soluble, ion-exchangeable, carbonate-bound, and Fe-Mn oxide-bound Cd, respectively. This study provides a theoretical basis for evaluating soil Cd behaves in crude oil contaminated wetlands in cold regions.

Water quality management of micro swamp wetland based on the “source-transfer-sink” theory: A case study of Momoge Swamp Wetland in Songnen Plain, China

Swamp wetlands play a pivotal role in conserving water sources, regulating river runoff, and maintaining water safety and balance. The study pioneers a new research framework in the field of pollution ecology of swamp wetlands, with a focus on the complex “source-transfer-sink” processes affecting water quality in micro swamp wetlands, an area previously under-researched. Taking the Momoge Wetland in the Songnen Plain as an example, we innovatively combined the “source-transfer-sink” theory with landscape patterns, topographic factors, and their impacts on wetland water quality. Using Partial Least Squares Structural Equation Modeling (PLS-SEM), our research quantifies and models the relationships among various environmental factors. This approach reveals how landscape patterns influence pollutant migration and water quality at a micro-scale. Our findings suggest that a 700-m buffer zone is most effective in capturing the fluctuations in water quality in arid wetlands, which is crucial for wetland management practices. We identified the main pollution sources in the Momoge Wetland, including sediment (21.60%), vegetation (24.94%), livestock and crop-related non-point sources (41.21%), and hydrodynamic factors such as water diversion (12.25%). In pollutant migration, land use emerged as the most significant factor affecting water quality (56.64%), followed by landscape patterns (25.54%). Notably, our study finds that grasslands are essential for water purification, and a uniform distribution of landscape patches significantly improves water quality. This research marks a significant stride in understanding and optimizing landscape patterns to enhance water quality in micro swamp wetlands. The insights gained are invaluable for the protection of these ecosystems and promoting their ecological value functions, providing a reference point for future wetland conservation and management strategies.

Implications of tussock degradation for soil properties in Momoge wetland, Northeast China

Carex schmidtii wetland, as a unique landscape in the Momoge National Nature Reserve, has suffered from serious degradation due to climate change and anthropogenic disturbance before 2017 and soil properties of degraded tussock meadows have changed in last 30 years. In the present work, typical (TT), slightly degraded (SLT), severely degraded (SET) and completely degraded (CDT) tussock wetlands based on plant coverage was used to construct the degradation succession so as to study the effects of tussock degradation on soil properties. Soil physicochemical properties, stable isotopes of carbon (δ13C) in plants and soil organic carbon (SOC) were thoroughly investigated in field so as to predict the consequences of tussock degradation. Results showed that soil pH value was decreased with the degree of tussock degradation increased. The SOC, total nitrogen and total phosphorus of SLT had peak values among the four wetlands. The δ13C value in soil and plants demonstrated that the change of SOC during degradation process have no significant relevance with Carex schmidtii. Principal component analysis indicated that the clusters of TT and SLT are different from SET and CDT. Tussock degradation had a significant negative effect on soil properties. The findings can contribute to establishing the evidence for predicting the influences of tussock degradation on soil properties in Momoge wetland.

Freeze-thaw cycles alter the growth sprouting strategy of wetland plants by promoting denitrification

Freeze-thaw cycles exert an important abiotic stress on plants at the beginning of winter and spring in mid-to-high latitudes. Here, we investigate whether the effects of freeze-thaw cycles are carried over into the growing season in wetlands. We conduct a temperature-controlled experiment under two freeze-thaw and two flooding conditions on a typical plant (Scirpus planiculmis) and soil from the Momoge wetland (China) and analyze the microbial nitrogen metabolism, based on metagenomic sequencing. We show that freeze-thaw cycles earlier in the year significantly inhibit plant sprouting and early growth. Specifically, they promote denitrification and thus reduce nitrogen levels, which in turn intensifies nitrogen limitation in the wetland soil. We find that plants tend to sprout later but faster after they are exposed to freeze-thaw cycles. Wetland flooding could alleviate these medium-term effects of freeze-thaw cycles. Our results suggest that wetland plants in mid-to-high latitudes have evolved sprouting and growth strategies to adapt to climatic conditions at the beginning of winter and spring.

Community diversity of soil meso-fauna indicates the impacts of oil exploitation on wetlands

Soil meso-fauna can indicate ecological health and provide biotic metrics for evaluating ecosystem damage and environmental changes. However, the roles of the soil meso-fauna in wetlands affected by oil exploitation have rarely been studied. This study investigated the community of the soil meso-fauna and the soil environmental quality in the oil exploitation area (oil well area, transitional area, and natural area) of the Momoge wetland, China. The results revealed that the oil pollutants (polycyclic aromatic hydrocarbons, PAHs) in the oil exploitation area mainly contained 2–3 rings soil PAHs. Oil exploitation mainly affected the soil meso-faunal community by changing the soil environment and vegetation characteristics. The abundance and richness of the soil meso-fauna were negatively affected by oil exploitation, and the richness responded more sensitively than the abundance. The diversity and taxa composition of the soil meso-fauna can be used to indicate the impacts of oil exploitation on wetland ecosystems and assess the ecological health of wetlands. The terrestrial taxa of the soil meso-fauna in wetlands (Coccoidea, Carabidae larvae, Hydrophilidae larvae, and Aphididae) could tolerate the oil pollutants and intense exploitation disturbance, indicating a highly disturbed wetland ecosystem. The aquatic (Chironomidae) and terrestrial taxon (Tenebrionoidea) indicated an intermediately disturbed wetland ecosystem. The aquatic (Enchytraeidae and Tabanidae) and non-aquatic taxa (Lposcelididae, Oecobiidae, and Tenthredinidae) indicated an undisturbed natural wetland ecosystem. The results of this study provide promising opportunities for oil production management and conservation efforts for wetland resources and biodiversity.

Flooding effects on population and growth characteristics of Bolboschoenus planiculmis in Momoge wetland, northeast China

Due to the interactive influences of climate change and human activities, flooding events are becoming an increasingly more serious abiotic stress in wetland ecosystems. Bolboschoenus planiculmis is a critical target plant species for the restoration of degraded wetland in the Momoge National Nature Reserve (MNNR), Northeast China. To investigate B. planiculmis growth response under different flooding conditions, we conducted comparative field studies of its population traits and ecological characteristics under alternate wetting to flooding (AF) and continuous flooding (CF) conditions. Under AF conditions, the B. planiculmis population significantly increased, its cover differed significantly (except June) compared to CF conditions, and flood stress significantly promoted its height. Flood events caused seasonal changes in morphological characteristics, especially stem and leaf length which increased in the growth period, and leaf width and area that significantly differed in June. B. planiculmis tuber biomass under CF condition was significantly higher than AF condition in May. B. planiculmis biomass was greater in AF, compared to CF conditions in the mid-late growth period, and its below-aboveground biomass ratio initially decreased before increasing, which indicated that the growth strategy was a trade-off between matter production and allocation during flooding. Flooding conditions had a significant effect on population traits and ecological characteristics, and AF conditions more strongly promoted B. planiculmis population development. Appropriate seasonal regulated floodwater management during the growth stage will assist B. planiculmis growth. Our findings provide invaluable supporting information for B. planiculmis MNNR wetlands restoration and management.

Differences in soil microbial response to anthropogenic disturbances in Sanjiang and Momoge Wetlands, China.

To understand the response of soil microbial communities in different types of wetlands to anthropogenic disturbances, this study focused on a freshwater wetland (Sanjiang Wetland) and a salt marsh (Momoge Wetland) and sampled cultivated, degraded, and natural soils in these wetlands. High-throughput sequencing was applied to characterize the soil microbial community composition, and physicochemical properties, including pH, total nitrogen, total carbon, and soil water content (SWC), were measured. The results revealed that the total nitrogen, total carbon, and SWC were significantly lower in disturbed soil in the freshwater wetland but higher in the salt marsh. Generally, under anthropogenic disturbances, microbial community diversity decreased in the freshwater wetland and increased in the salt marsh. The bacterial community structure in the salt marsh was more sensitive than that in the freshwater wetland, while the fungal community structure in the freshwater wetland was more susceptible than that in the salt marsh. The results of indicator value analyses revealed specific issues in two wetlands, such as methane generation and anoxic conditions. This study shows that soil microbiomes in two types of wetlands respond differently to human activities, which implies that the type of native wetlands should be considered in the exploitation of wetlands.

Soil Degradation Effects on Plant Diversity and Nutrient in Tussock Meadow Wetlands

Soil degradation, a growing problem in the arid and semi-arid area, significantly influences wetland dynamics and nutrient cycling. Using tussock wetlands as objectives, this study aims to explain the effects of long-term soil degradation on plant diversity and dominant species and identify the impacts of long-term soil degradation, growing month, species, and their interactions on plant nutrient stoichiometry in Momoge wetland. Field experiments were undertaken to explore the responses of plant diversity and nutrient to soil degradation in Momoge wetland. The relationships between plant nutrient and soil physicochemical properties were examined by canonical correspondence analysis (CCA). Soil nutrient significantly decreased in degraded tussock wetlands. Long-term soil degradation altered plant diversity and the important values of dominant species. Plant nutrient indicated that the effects of soil degradation on plant carbon, nitrogen, and phosphorus were not significant at the single species level. Furthermore, plant stoichiometric patterns were not sensitive to soil degradation. However, both the N/P ratio in soil and plants showed a nitrogen limitation for the plant growth in wetlands. The CCA indicated that the soil total nitrogen and electrical conductivity were the primary factors affecting the cycle of biogenic elements in tussock wetlands. Results highlight the differences in biogenic elements in wetland soil and vegetation and identify the significant effects of soil degradation on the wetland plants. These findings suggest that the variation of nutrient availability and electronic conductivity affects the growth of the wetland species.

Numerical Analysis of the Impact Factors on the Flow Fields in a Large Shallow Lake

Wetland acts as an important part of climatic regulation, water purification, and biodiversity maintenance. As an integral part of wetlands, large shallow lakes play an essential role in protecting ecosystem diversity and providing water sources. Baihe Lake in the Momoge Wetland is one such example, so it is necessary to study the flow pattern characteristics of this lake under different conditions. A new model, based on the lattice Boltzmann method, was used to investigate the effects of different impact factors on flow fields, such as water discharge from surrounding farmland, rainfall, wind speed, and aquatic vegetation. Importantly, this study provides a hydrodynamic basis for local ecological protection and restoration work.

Physiological responses of Carex schmidtii Meinsh to alternating flooding-drought conditions in the Momoge wetland, northeast China

Alternating flooding-drought conditions have been shown to be an effective water-saving method to restore wetland plants in arid and semi-arid regions. Carex schmidtii is a critical plant species for the restoration of degraded wetlands in the Momoge National Nature Reserve (MNNR) in northeast China. Comparative studies of plant leaves, under permanent inundation condition (AF condition) and 30 d cycles of alternate flooding-drought conditions (A30), were carried out. Plant leaf morphology and biomass, as well as physiological traits and nutrient stoichiometry, were analyzed to understand the mechanism of C. schmidtii to environmental factors. It was well demonstrated that growth of plants under A30 condition achieved significantly higher length and the ratio of leaf withering (by 9.02 and 6.73 times, respectively), compared with those obtained under AF condition. Dry leaf matter content, varying between 37.8% and 44.6% under the A30 condition was 18.1% greater than those obtained under the AF condition. Initial plant treatment was found to greatly increase chlorophyll content and superoxide dismutase activity. The proline content of C. schmidtii under A30 condition was significantly higher, whereas plant leaf nitrogen and phosphorus contents under A30 condition were only slight lower than under AF condition. Hence, alternating flooding-drought conditions initiated in the early growth stage had a beneficial effect on their adaptability to environment changes; assisting plant growth and biomass accumulation when water supply reduced. Overall, the results provide supporting information for the restoration and management of C. schmidtii tussocks in degraded wetlands in semi-arid regions.

Partitioning daily evapotranspiration from a marsh wetland using stable isotopes in a semiarid region

Abstract The hydrological process of evapotranspiration (ET) plays an important role in water circulation in wetlands, and understanding the contributions of wetland ET to local and regional water cycles can help in designing effective wetland management strategies. In this paper, a numerical model, vegetation indexes, and stable isotopes were integrated to partition ET in the Momoge Wetland to understand hydrological processes and calculate the contribution of wetland ET to local hydrological cycling. The results of the non-steady state (NSS) model indicated clear deviation of leaf water enrichment (δLb) from an isotopic steady state (ISS) for Phragmites australis, and the model accuracy improved particularly in the early morning and evening when air moisture was highest during the day. The isotopic mass balance showed that E and T contributed approximately 62% and 38% to ET, respectively. Using the estimated proportion of T to ET, in combination for the measured leaf transpiration, total ET was estimated at approximately 8.76 mm d−1. Additionally, the amount of ET clearly changed on an hourly scale, with most primarily occurring at approximately noon. Based on comparison among internationally important wetlands distributed in northeast China, the results in this study are reasonable and will provide theoretical data for wetland water resources management.

Distribution Characteristics and Risk Assessment of Polycyclic Aromatic Hydrocarbons in the Momoge Wetland, China.

The Momoge Nature Reserve is the research object of this study. Through field sampling, laboratory experiments and analysis, the contents, distribution characteristics, source identification, pollution levels and risk levels of polycyclic aromatic hydrocarbons (PAHs) in wetland soils were studied. The results show that the sum content of 16 types of PAHs (Σ16 PAH) in the wetland soil was within the range (0.029–0.4152) mg/kg. PAHs in wetland soil are primarily 2–3-rings PAHs. PAHs in the Momoge wetland soil have multiple sources: petroleum, combustion of petroleum and coal, and others, of which petroleum and the sum of combustion of petroleum and coal account for 38.0% and 59.3%, respectively. Research, using the standard index and pollution range methods, shows that the content of the PAH labelled Nap, found in the Momoge wetland soil, is excessive; some sampling sites exhibit a low level of pollution. The result of a biotoxicity assessment shows that there are two sampling sites that occasionally present an ecological toxicity hazard. The result of the organic carbon normalization process shows that an ecological risk exists only at sampling site No. 10.

Differential Flooding Impacts on Echinochloa caudata and Scirpus planiculmis: Implications for Weed Control in Wetlands

Scirpus planiculmis, a perennial herb typically grown from tubers in wetlands, is the main food species for migratory Siberian white crane (Grus leucogeranus) in Momoge National Nature Reserve (MNNR), northeastern China. However, Echinochloa caudata, an annual weed propagated only from seed, became the dominant species in the majority of the rewetted site in Momoge wetland, which decreased the habitat quality for Siberian white crane. Early flooding during the first few days of germination kills plant seedlings of many species and thus may consequently be used to effectively suppress undesired species. A pot experiment was conducted to determine the effects of different flooding depths on the regeneration of both E. caudata and S. planiculmis. Five water depths (−5, 0, 5, 10 and 20 cm water depth relative to sediment surface) and four flooding regimes (one, four, eight and 16 days after sowing (DAS)) were evaluated. The results showed that 0 cm water depth was most favorable for both the survival and growth of E. caudata seedlings. Water depths of 10 or 20 cm significantly reduced both the survival rates and biomass accumulation of E. caudata seedlings at one, four or eight DAS. Seedling height of E. caudata was not affected by water depths of 0–10 cm when flooded at one or four DAS and was increased by flooding (5–20 cm water depth) when the flooding was delayed to eight or 16 DAS. Flooding did not significantly affect the shoot number, plant height or dry biomass of S. planiculmis. Our results provide valuable information for the control of E. caudata using hydrology in wetlands dominated by S. planiculmis, and these strategies can be used to protect the habitat of the Siberian white crane.

Adaptive Significance of and Factors Affecting Plasticity of Biomass Allocation and Rhizome Morphology: a Case Study of the Clonal PlantScirpus planiculmis(Cyperaceae)

ABSTRACT: In plants, biomass allocation and rhizome morphological plasticity reflect different strategies of adaptation to the environment. The aims of this study were to explore the patterns of allocation to different components of the belowground system, and to evaluate the effects of environmental factors on the plasticity of biomass allocation and rhizome morphology. We conducted a survey of the clonal plant, Scirpus planiculmis, in the Momoge wetland in northeastern China. Samples were collected at three sites. Site I is the washland of a seasonal lake. Site II is a permanent lake. Site III belongs to the bank of a recessive river. The average number of sampled plants was 686.25±91.61 per site. We determined the biomass of different plant parts (aboveground part, root, tuber, rhizome) and measured parameters of rhizome morphology (specific rhizome length, average rhizome diameter). Edaphic factors (soil moisture content, organic matter, available phosphorus, available potassium, pH, electrical conduc...

Effects of crude oil contamination on soil physical and chemical properties in Momoge wetland of China

Large oilfields are often coincidentally located in major river deltas and wetlands, and potentially damage the structure, function and ecosystem service values of wetlands during oil exploration. In the present study, the effects of crude oil contamination during oil exploration on soil physical and chemical properties were investigated in marshes of the Momoge National Nature Reserve in Jilin Province, China. The concentrations of total petroleum hydrocarbons in the marsh soil near the oil wells are significantly higher than those in the adjacent control marsh. Soil water contents in oil-contaminated marshes are negatively correlated with soil temperature and are significantly lower than those in the control area, especially in fall. Crude oil contamination significantly increases the soil pH up to 8.0, and reduces available phosphorus concentrations in the soil. The concentrations of total organic carbon are significantly different among sampling sites. Therefore, crude oil contamination could potentially alkalinize marsh soils, adversely affect soil fertility and physical properties, and cause deterioration of the marshes in the Momoge National Nature Reserve. Phyto-remediation by planting Calamagrostis angustifolia has the potential to simultaneously restore and remediate the petroleum hydrocarbon-contaminated wetlands. Crude oil contamination affects the soil physical and chemical properties, so developing an effective restoration program in the Momoge wetland is neccesary.

Floodwater utilisation values of wetland services – a case study in Northeastern China

Abstract. Water plays a significant role in wetlands. Floodwater utilisation in wetlands brings a wide range of wetland services, from goods production and water regulation to animal protection and aesthetics related to water supply in wetlands. In this study, the floodwater utilisation values of wetland services were estimated within the Momoge wetland and Xianghai wetland in western Jilin province of northeastern China. From 2003 to 2008, the floodwater diverted from the Nenjiang and Tao'er River is 381 million m3, which translates into a monetary value of approximately 1.35 billion RMB in 2008 (RMB: Chinese Currency, RMB 6.80 = US$ 1), and the ratio of economic value, eco-environmental value, and social value is 1:12:2. Besides the monetary value of the water itself, excessive floodwater utilisation may bring losses to wetlands; the threshold floodwater utilisation volumes in wetlands are discussed. Floodwater utilisation can alleviate water shortages in wetlands, and the evaluation of floodwater utilisation in wetland services in monetary terms is a guide for the effective use of the floodwater resources and for the conservation of wetlands.

莫莫格湿地芦苇对水盐变化的生理生态响应

Understanding the eco-physiological response characteristics of Phragmites australis to water-salt condition is the key of determining the threshold of wetland ecological water requirement,in order to supply a feasible method for calculating the wetland ecological water requirement and scientific base for wetland restoration.By field investigation of Phragmites australis in Momoge wetland,we analyzed the relationship between eco-physiological characteristics of Phragmites australis and water-salt gradient with method of redundancy analysis(RDA) by using CANOCO software in Version 4.5.The results showed that the combination of three environmental factors including water depth,Na+ and HCO-3,explained 54.7% of the variation of eco-physiological responses of Phragmites australis,suggesting that the three environmental factors led to great changes in eco-physiological responses of Phragmites australis.Water depth was the key environmental factor influencing the growth of Phragmites australis.There was a significant positive correlationship between water depth and the eco-physiological characteristics including plant height,biomass,chlorophyll content,maximum photosynthesis efficient(FV/FM) and maximum photosynthesis performance index(PIABS).There was no significant correlationship between Na+/HCO-3 and the characteristics of Phragmites australis.The results suggested that it is the key point in the process of wetland restoration in mild or moderate saline-alkaline wetland to consider the influence of water depth on the growth of Phragmites australis,and secondly consider the effect of Na+/HCO-3,and determining the ecological water depth and fulfilling the ecological water requirement.

Study on the relationship between scirpus planiculmis grow and Soil salinity

Abstract Abstract. Through study on the relationship between scirpus planiculmis growth and soil in momoge wetland, it is discovered that the relationship between the average plant height and soil salt content is:, relationship between aboveground biomass and soil salt content:; The critical growth value of the Scirpus planiculmis without or with small outside interference is relatively small; their height, ground biomass, salinity content are 24.4 cm, 4.745 g and 1.100%, respectively; when there is outside interference in a certain time, the critical value of growth of Scirpus planiculmis is high,their height, ground biomass, salinity content are 23.2 cm, 4.179 g and 0.977%, respectively.

Effects of crude oil residuals on soil chemical properties in oil sites, Momoge Wetland, China

Crude oil exploration and production has been the largest anthropogenic factor contributing to the degradation of Momoge Wetland, China. To study the effects of crude oil on wetland soils, we examined the total petroleum hydrocarbon (TPH), total organic carbon (TOC), total nitrogen (TN), and total phosphorus (TP), as well as pH and electricity conductivity (EC) from oil sites and uncontaminated areas in the Momoge Wetland. All contaminated areas had significantly higher (p < 0.05) contents of TPH and TOC, but significantly lower (p < 0.05) TN contents than those of the uncontaminated areas. Contaminated sites also exhibited significantly higher (p < 0.05) pH values, C/N and C/P ratios. For TP contents and EC, no significant changes were detected. The level of soil contamination and impact of oil residuals on soil quality greatly depended on the length of time the oil well was in production. Oil residuals had caused some major changes in the soils' chemical properties in the Momoge Wetland.