Restoration Of Wetland Ecosystems Research Articles

The Potential Role of Phytoplankton Functional Groups Under Anthropogenic Stressed Wetlands: Characterizing The Environmental Sensitivity.

Anthropogenic and climatic changes are continuously altering the freshwater plankton, necessitating an evaluation of the complex structure of plankton communities to understand and mitigate these impacts. In this context, the present study focuses on evaluating the structure of plankton communities, specifically Phytoplankton Functional Groups (FGs) for assessing the environmental sensitivity of wetlands under changing scenario. These FGs are defined by shared adaptive features rather than taxonomic traits. Over the period from 2016 to 2018, two ecologically distinct wetlands were examined, analysing their phytoplankton FGs and their relationship with water quality parameters. Ecohydrological data revealed significant seasonal variations (p ≤ 0.05) in key parameters such as water depth, temperature, pH, electrical conductivity, dissolved oxygen, total alkalinity, total hardness, NO3-N, and PO4-P. Notably, there were no significant differences observed among the sampling stations within each wetland. A total of 125 phytoplankton genera/species were classified into 23 FGs in the open wetland and 22 FGs in the closed wetland. Spatial and seasonal analyses of dominant FGs suggested both wetlands were experiencing pollution pressures. This study highlights the powerful role of phytoplankton functional groups (FGs) as bioindicators of wetland health, uncovering pollution pressures. In open wetlands, 15 phytoplankton FGs with 36 key taxa (Indicator Value ≥ 40%) emerged as critical indicators, while in closed wetlands, only 10 FGs with 17 taxa were identified. To assess eutrophication, the occurrence of these indicator species was evaluated using BVSTEP function analysis. The study recommends pollution reduction in catchment areas and restoration of riverine connectivity to enhance FG diversity. Phytoplankton FG methodologies are deemed effective for assessing the environmental sensitivity of wetlands significantly impacted by human activities. This research offers a scientific foundation for the evaluation and restoration of wetland ecosystems.

The Effects of Climate Change on the Distribution Pattern of Species Richness of Endemic Wetland Plants in the Qinghai-Tibet Plateau.

Wetland ecosystems in the Qinghai-Tibet Plateau (QTP), the region with the richest biodiversity and the most important ecological barrier function at high altitudes, are highly sensitive to global change, and wetland plants, which are important indicators of wetland ecosystem structure and function, are also threatened by wetland degradation. Therefore, a comprehensive study of changes in the geographical distribution pattern of plant diversity, as well as species loss and turnover of wetlands in the QTP in the context of global climate change is of great importance for the conservation and restoration of wetland ecosystems in the QTP. In this study, species turnover and loss of 395 endemic wetland plants of the QTP were predicted based on the SSP2-4.5 climate change scenarios. The results showed that there were interspecific differences in the effects of climate change on the potential distribution of species, and that most endemic wetland plants would experience range contraction. Under the climate change scenarios, the loss of suitable wetland plant habitat is expected to occur mainly in parts of the southern, north-central and north-western parts of the plateau, while the gain is mainly concentrated in parts of the western Sichuan Plateau, the Qilian Mountains, the Three Rivers Source Region and the northern Tibetan Plateau. Overlaying the analysis of priority protected areas with the established protected areas in the QTP has resulted in the following conservation gaps: the eastern Himalayan region, midstream of the Yarlung Zangbo River, the transition zone between the northern Tibetan Plateau and the Hengduan Mountains, Minshan-Qionglai mountain, Anyemaqen Mountains (southeast) to Bayankala (southeast) mountains, the southern foothills of the Qilian Mountains and the northern Tibetan Plateau region. In the future, the study of wetland plant diversity in the QTP and the optimisation of protected areas should focus on the conservation gaps. This study is of great importance for the study and conservation of wetland plant diversity in the QTP, and also provides a scientific basis for predicting the response of wetland plants to climate change in the QTP.

Effects of different restoration stages on soil microbial community composition and diversity in Naolihe Wetland, China.

Soil microorganisms can be used as one of the important indicators of wetland ecosystem restoration. To study the effects of different restoration stages on soil microbial community composition and diversity in Naolihe Wetland, we employed a "time and space parallel" method. Four restoration stages, namely corn field (Corn), short-term restoration wetland (2 years, ST), long-term restoration wetland (8 years, LT) and natural wetland (>25 years, NW), were selected to represent the restoration time and geographical location in Naolihe Nature Wetland. We investigated the composition and diversity of soil microbial communities in different restoration wetland (from corn fields to natural wetlands) by using 16S rRNA and ITS rRNA gene sequencing. We also performed chemical experiments to measure soil enzyme activity and physicochemical properties at each sampling site. The results showed that soil physicochemical properties and enzyme activities significantly differed with the extension of wetland restoration years (p < 0.05). Proteobacteria, Acidobacteria, and Actinobacteria are the most dominant phyla in bacterial. The alpha diversity of soil bacteria was the highest in the corn field (Corn), and ST-LT-NW first decreased and then increased with the extension of wetland restoration years. There are two most dominant phyla (Ascomycota and Mucoromycota) in fungal. However, the alpha diversity of soil fungi was the lowest in the Corn and LT stage, and ST-LT-NW first decreased and then increased with the extension of wetland restoration years. The research findings indicated that the changes in soil physicochemical properties with the extension of wetland restoration years play a significant role in shaping the structure and diversity changes of soil microbial communities. Through the analyses of bacterial and fungal functions using the FUNGuild and FAPROTAX databases, the results showed that the abundance of aerobic bacteria in the soil increased more than that of anaerobic bacteria as the wetland restoration years prolonged, while the abundance of saprotrophic, symbiotic, and pathogenic fungi in the soil significantly decreased with the prolonged wetland restoration years. This study will help us better understand the process of restoration after farmland abandonment, providing valuable reference information for the implementation of a series of wetland ecological restoration projects in the future.

Performance evaluation of backscattering coefficients and polarimetric decomposition parameters for marsh vegetation mapping using multi-sensor and multi-frequency SAR images

Wetland vegetation is the basis for wetland ecosystems to regulate climate change, carbon sequestration and maintain biodiversity. Therefore, high-precision mapping and dynamic monitoring of wetland vegetation are essential for the effective management, restoration and sustainable development of wetland ecosystems. This study addressed to explore classification performance of backscattering coefficients and polarimetric decomposition parameters of multi-frequency SAR images, including single-polarimetric X-band TerraSAR (TS), full-polarimetric C-band Radarsat-2 (RS) and L-band ALOS PALSAR-2 (PS) for marsh vegetation mapping in Honghe National Nature Reserve, Northeast China. We proposed two transfer-learning strategies, and examined the feasibility of transfer-learning vegetation classifications between optical and SAR sensors, different frequencies SAR (X-, C- and L-band) and its derivative images, respectively. This paper further compared transfer-learning classification performance of marsh vegetation from polarimetric decomposition parameter images to backscattering coefficient images under the same SAR sensors. The results indicated that: (1) The three SAR images performed good classification ability in identifying marsh vegetation with the overall accuracies (OA) ranging from 0.74 to 0.88. For the same frequency SAR images, polarimetric decomposition parameters outperformed backscattering coefficients with an OA improvement ranging from 0.24 % to 2.41 %; (2) The longer wavelength SAR images produced better classification results, and L-band PS images realized the highest classification accuracy (OA = 0.871); (3) Full-polarimetric SAR images obtained the better transfer-learning classifications (OA > 0.8), and the transfer-learning classification ability of the same frequency SAR images outperformed the different frequencies; (4) The transfer learning classification results between SAR sensors outperformed that of between optical and SAR images. The results of this study provide a scientific basis for wetland change monitoring conservation and sustainable development.

Assessing Tidal Hydrodynamics in a Tropical Seascape Using Structure‐from‐Motion Photogrammetry and 2D Flow Modelling

Tidal wetlands continue to be threatened by changes in seascape hydrological regime and connectivity resulting from human activities (e.g. urbanisation, engineered barriers) and climate change. Reliable and parsimonious models that can be used by managers and practitioners to simulation tidal wetland hydroperiod dynamics (duration, depth, and frequency of tidal inundation) at high-resolution are limited presumably because these ecosystems have very low elevation across their flooding plain. Here, we developed a two-dimensional hydrodynamic model parameterised using a high-resolution (3 cm) and accurate (8-cm RMSE elevation error) digital elevation model (DEM) and land cover map (2-cm resolution) derived from unoccupied aerial vehicles (UAVs) structure from motion photogrammetry (SfM) to assist in the understanding of tidal wetland hydroperiod and hydrological connectivity of an upper tidal Australian tropical seascape. Ground-based water level datasets were used to calibrate and validate the model with higher accuracy (RMSE = 7 cm between maximum observed and simulated depth). The high-resolution approach demonstrates how small changes in topography such as vehicle tracks can interfere with hydrological connectivity. Centimetre-changes in tidal height resulted in important variations (10 ha) in the total area of the wetland being inundated, suggesting that small anthropogenic modifications of tidal inputs (e.g. culverts and sea-level rise) might have important implications on tidal wetland inundation patterns. Despite challenges related to reconstructing topography in densely vegetated areas and obtaining bathymetric data, the method developed here represents an accurate and cost-effective approach to quantify tidal wetland hydroperiod. This approach assists in planning, defining, and implementing effective and measurable restoration and protection projects of tidal wetland ecosystems. Graphical

The Impact of Restoration and Protection Based on Sustainable Development Goals on Urban Wetland Health: A Case of Yinchuan Plain Urban Wetland Ecosystem, Ningxia, China

Drawing heavily upon the Sustainable Development Goals (SDGs), an SDG–pressure–state–response (PSR)–ecological–economic–social (EES) model and an index system for wetland ecosystem health assessment were constructed from the three dimensions of environment, economy, and society. By using the Yinchuan Plain urban wetlands in the Yellow River Basin of China as a case study, their ecological health status from 2000 to 2020 was systematically evaluated by integrating information from remote sensing technology, geographic information technology, field sampling, information entropy (IE), a landscape index, and a Comprehensive Evaluation Index. The results show that the restoration and protection of wetland ecosystems have achieved remarkable results in the Yinchuan Plain. The wetland ecological health index has significantly increased from 0.26 to 0.67, which is an increase of 157.7%, and the health level increased from poor (II) to sub-healthy (IV). Factors restricting the healthy development of wetland ecology in the Yinchuan Plain include wetland construction, investment, population density, the number of tourists, and fertilizer use. The research results show that the wetland restoration and protection have achieved specific environmental, economic, and social results in the Yinchuan Plain. However, we also need to pay attention to increasing the investment in wetland environmental governance, strictly controlling the intensity of land use and the total amount of chemical fertilizer applied in various regions, scientifically carrying out wetland restoration and protection, reasonably coordinating the relationship between environment and society, and providing technical and decision-making support for wetland management and protection. This study provides a reference for the ecological governance and sustainable development of wetlands in large river basins worldwide.

Status of river-connected lakes under the influence of the Three Gorges Dam: research progress and prospect

The construction and operation of the Three Gorges Dam, the world's largest dam, has provided important support for national economic development and drinking water safety. However, the dam's construction has had a non-negligible impact on the ecosystem condition of lake wetlands in the middle and lower reaches of the Yangtze River, which has become a significant theme in recent scientific researches and policy works. Although previous studies have carried out detailed assessments of the relationship between the Three Gorges Dam and downstream lake wetland ecosystems, there has not been a comprehensive discussion. Based on the bibliometric method and the systematic collation of related research, this paper comprehensively reviewed the research progress and hot topics of the river-connected lakes in the middle and lower reaches of the Yangtze River under the influence of the Three Gorges Project. The results show that the number of related studies continued to grow during the study period, involving multiple research fields. The research hotspots focused on five fields: schistosomiasis, remote sensing monitoring of the landscape, water quality, water level and sediment. The disturbance of the Three Gorges Dam on lake water level, landscape heterogeneity and habitat quality may be the focus of further research. In addition, this study presents challenges and recommendations for future research directions. This paper aims to provide a constructive reference for the management of the Three Gorges Dam and the conservation and restoration of lake wetland ecosystems.

Different driving mechanisms of spatial heterogeneity at the community and landscape levels in the wetland ecosystem dominated by hydro‐ecological processes

AbstractThe analysis of wetland patterns and their driving mechanisms is the research focus of discussion in wetland ecology. In this study, we tried to analyse the spatial differentiation patterns of community and landscape levels dominated by hydro‐ecological processes. The spatial differentiation patterns of landscape patterns and their driving mechanisms were explored in focus. This study was based on 30‐year land cover data of Baiyangdian Wetland Nature Reserve in North China Plain, China, constructing an ecological response relationship matrix between inundation frequency and vegetation cover frequency for the spatial divide at the community and landscape level. By constructing a landscape index set and analysing the index set using clustering, non‐metric multidimensional scale analysis, discriminant and redundancy analysis, we finally obtained the differentiation characteristics of wetland landscape patterns and their driving mechanisms. The spatial differentiation of community levels along the water level gradient showed a banded distribution pattern of submerged‐floating‐emerge to meadow shrubs, but the stability of the hydrological regime dominated the spatial differentiation of landscape levels. Wetland landscapes along the stability gradient of the hydrological regime were divided into stable and fluctuating zones. The stable zone had the landscape pattern characteristics of low fragmentation, simple and regular shape and high numbers of different patch types; the landscape pattern of the fluctuating zone was characterized by a high fragmentation and complex shape, with a small number of different patch types and a non‐uniform distribution. The analysis of the driving mechanism showed that the stability of the hydrological regime was the only reason for the formation of the landscape pattern of the stable zone. The combined effect of human‐dominated and natural‐supplemented effects jointly drove the formation of the landscape pattern of the fluctuating zone. The influence of human on the landscape pattern of the fluctuating zone showed a trend of spatial expansion from high areas to shallow water areas. The combination of traditional landscape indices and aquatic ecological processes characterized the spatial differentiation of wetland landscape patterns, and also verified the feasibility of this method. This study was a successful example of conducting ecological process‐oriented landscape level spatial differentiation analysis. The results of the study are intended to provide recommendations for the rational and effective use and precise conservation of wetland plant and animal resources and the restoration of wetland ecosystems.

Priorities identification of habitat restoration for migratory birds under the increased water level during the middle of dry season: A case study of Poyang Lake and Dongting Lake wetlands, China

The distribution of wetland ecosystem restoration sites is uneven and resources are limited, so priority identification is essential for rational resource allocation and reduction of biodiversity loss. Under the influence of human activities and climate variability, the water level during the middle of dry season (MDS) had a significant tendency to increase in Poyang Lake (PYL) and Dongting Lake (DTL), which directly affected the habitat suitability (HS) of migratory birds and threatened their existence. Based on the data of HS and weight of migratory birds, four evaluation indexes, namely, the accuracy of priority identification (API), geographical area equalization (GAE), the spatial autocorrelation consistency (SAC) and comprehensive evaluation index (CEI), were used to evaluate and compare the priorities identification effects of four classification methods, namely, natural breaks method, quantile method, equal interval method, and geometric interval method. The results showed that the geometric interval method and the quantile method are the best methods to identify the priority of habitat restoration of migratory birds in PYL and DTL wetlands, respectively, under the condition of increased water level (IWL) during the MDS. The method of priority identification proposed in this study and its results can provide a scientific basis for the regulation of wetland resources and the conservation of biodiversity (especially migratory birds).

Influences of anthropogenic acids on carbonate weathering and CO2 sink in an agricultural karst wetland (South China)

Carbonate minerals are the largest carbon (C) reservoir on earth. Quantitative assessment of carbonate weathering and CO2 sink flux caused by anthropogenic acids in karst wetland regions is imperative to improve understanding of the hydrogeochemical evolution and global C cycle in karst ecosystem. In this study, a typical field observation was conducted in the Huixian karst wetland (HKW) in South China. The hydrogeochemical and isotopic (δ15N-NO3–, δ18O-NO3–, and δ13CDIC) analyses combined with the MixSIAR model and stoichiometric coefficients were used to quantitatively estimate the influence of H2CO3, HNO3 and H2SO4 on carbonate weathering and CO2 sink flux. The results obtained showed that anthropogenic HNO3 and H2SO4 affect carbonate weathering in the HKW, evidenced by the significant correlations between hydrogeochemical parameters and δ13CDIC value. The quantitative results showed high contributions of HNO3 and H2SO4 to carbonate weathering in karst groundwater, with contribution ratio values of 20.91 ± 19.29 and 21.69 ± 26.88%, respectively. Besides karst water over-exploitation, this finding suggested that these anthropogenic acids were also an important cause of a decrease in ecological water levels, resulting in the shortage of karst water resource and degradation of wetland ecosystem. Moreover, the involvement of anthropogenic acids in the natural chemical weathering has significantly decreased the CO2 sink flux by 11.23 ± 7.94 and 41.60 ± 30.24% for surface water and groundwater, respectively, thereby potentially affecting the karst C cycle and global climate change. This present study provided an integrated quantitative approach for estimating the influence of H2CO3, HNO3, and H2SO4 on carbonate weathering and CO2 sink in karst wetland regions. Our study highlighted that the effects of anthropogenic acids on carbonate weathering need to be considered in future studies on the restoration of wetland ecosystems, particularly in intensive agricultural study areas.

Plant Diversity and Quantitative Characteristics Of Wetland Community on the North Bank of Hanjiang River in Cheng GU, Shaanxi Province, China

Four water ecological surveys were carried out on the north bank of Hanjiang river in two seasons from 2020 to 2021. Based on the field wetland quadrat survey and literature data, the species diversity index was determined. The research showed that there are 360 species of wetland plants belonging to 108 families and 264 genera on the north bank of Hanjiang river, and the geographical composition of seed plants is at the genus level, mainly temperate distribution types, with 160 species. In the community species diversity index, the mean value of Patrick index was 18.80 ± 5.19. The mean Shannon Wiener diversity index was 2.15 ± 0.39. The mean value of Simpson dominance index was 0.81 ± 0.10. The average Pielou evenness index was 0.75 ± 0.10. The mean value of Margalef index was 3.44 ± 0.87. The Patrick index and Margalef index of the Bidens pilosa form were the lowest. The Shannon-Wiener diversity index，the Simpson index，and the Pielou index of the Potamogeton malaianus form were the lowest. The Patrick index of the Colocasia esculenta form was the highest,and the Pielou of the Sapium sebiferum form was the highest. The Shannon- Wiener diversity index and Simpson index of the Populus canadensis form group were the highest, and the Margalef index of the Flueggea virosa form was the highest. The research results provide basic data and scientific basis for the protection and restoration of wetland ecosystems and management of wetland resources in Yuan'an and similar areas. Bangladesh J. Bot. 51(4): 839-848, 2022 (December) Special

Seasonal Dynamics of Vegetation in the Wetlands of the Lower Dniester NNP Based on Remote Data from the Landsat-8 Satellite

Over the season of 2020, the vegetation dynamics of the wetlands in the Lower Dniester National Nature Park were examined using the indices &lt;i&gt;NDVI &lt;/i&gt;(Normalized Difference Vegetation Index) and &lt;i&gt;VCI&lt;/i&gt; (Vegetation Condition Index) on the basis of Landsat-8 satellite remote sensing data. The results demonstrated that distribution of values throughout the vegetation season did not correspond to normal distribution, indicating variety of their habitat conditions. The vegetation development in spring was negatively affected by the pyrogenic factor, which formed some areas without vegetation and with poorly developed vegetation. Sharp increase in &lt;i&gt;NDVI&lt;/i&gt; values in early summer occurred due to development of wetland ecosystems' edifier &lt;i&gt;Phragmites australis&lt;/i&gt;, whose stems emerged from the pickle stage and developed a leaf lamina. In this period, the well-developed vegetation prevailed, its total area exceeded 97&amp;#37;. In autumn, the areas of the developed vegetation gradually decrease, whereas areas of the poorly developed increased. The results of the research showed effectiveness of remote sensing of wetland areas using &lt;i&gt;NDVI &lt;/i&gt;and &lt;i&gt;VCI&lt;/i&gt; to assess vegetation state; it also can be used for the purposes of the conservation, restoration and sustainable use of wetland ecosystems of the north-west Black Sea coastal area under increasing anthropogenic pressure and global climate change.

A dataset of mangrove forest changes on Hainan Island based on GF-2 data during 2015–2019

Mangrove forests are wetland ecosystems in the coastal zone with important ecological and eco-economic service values. At the same time, mangrove forests are vulnerable ecosystems, being under threat from both natural and anthropogenic forces, so mangrove monitoring is a permanent task. The development of remote sensing technology has provided an efficient and convenient means for mangrove monitoring. In this study, we adopted a support vector machine (SVM) classification method with Gaussian radial kernel function, penalty factor of 100 and Gamma function 0f 0.022 to obtain a dataset of mangrove forest changes on Hainan Island from 2015 to 2019 by using Gaofen-2 (GF-2) data in 2015, 2017 and 2019 in combination with field survey data. The overall classification accuracy of this dataset is more than 99%, and the data volume is 58.7 MB. It can be used as the basic data for the analysis of spatial and temporal changes of mangrove forests. It can also provide decision-making support for the restoration, protection and management of mangrove wetland ecosystems, and facilitate the ecological environment supervision in Hainan Province.

Inundation Depth Shape Phenotypic Variability of Phragmites australis in Liaohe Estuary Wetland, Northeast China

Inundation shifts plant growth, species diversity and ecosystem stability, but it remains unclear how inundation depth shapes the phenotypic variability of clonal plants in an estuary wetland. To reveal the response of clonal plant populations to inundation depth, we calculated the variation of Phragmites australis using shoot height, leaf length, leaf width, leaf biomass and panicle length in the Liaohe estuary wetland. Reproductive allocation was defined by the ratio of panicle length to shoot height. Linear regression showed that shoot height, leaf length, leaf width, leaf biomass and panicle length were negatively correlated with inundation depth, while the ratio of panicle length to shoot height was negatively correlated with inundation depth (p &lt; 0.0001). Based on data regarding the statistical differences of plant phenotypic traits among P. australis, we recognized populations had generated variation differentiation. Compared with other functional traits, the coefficient of variation of leaf-related traits were at a high level. Therefore, leaf parameters would be the most suitable, and they increased the area and weight to support the action of plants during floods. Multivariate statistical analysis suggested that P. australis populations in the Liaohe estuary wetland were divided into two phenotypic clusters, consistent with geographical distance and morphological similarity. Our results provide a novel perspective on the ecological strategy of cloned plants under inundation change and offer theories for the conservation and restoration of estuarine wetland ecosystems.

The role of moisture regime and hydro-topography on tropical wetland ecosystem management

Moisture and hydrological conditions have a close and fundamental relationship with tropical wetland ecosystems’ existence, characteristics, and function. Peatlands and mangrove ecosystems are wetland ecosystems but both have different unique edaphic characteristics so they are interesting as reference ecosystems. Events like land clearing, drainage, flooding, drought, and fires cause the degradation of peat and mangrove ecosystems in Indonesia. Moisture dynamics and hydro-topography will affect the quality of the land and the environment, so it is very important to study them to provide ecological information for the successful management and restoration of wetland ecosystems. This paper will discuss the role of moisture regimes and hydro-topography in the management of tropical peatlands and mangroves. This study uses a review method by data and information analysis from study reports, field observation notes, and journals simultaneously and in an integrated manner. Moisture regime and hydro-topography conditions on peatlands and mangroves indicate differences in vegetation types and key species. Hydrological characteristics and edaphic conditions are expected to become critical references in the effort to preserve and restore tropical wetland ecosystems, in this case, peatlands and mangrove ecosystems.

Competitive Relationship Between Cleistocalyx operculatus and Syzygium jambos Under Well-Watered Conditions Transforms Into a Mutualistic Relationship Under Waterlogging Stress.

Competition and abiotic stress such as waterlogging (WL) represent main factors limiting plant growth and determining plant resistance and distribution patterns in wetland ecosystems. One of the basic steps for wetland restoration is to plant trees to ensure a quicker recovery and prevent erosion. Plant survival and adaptation are considered criteria of principal priority for the screening of plant species for wetland ecosystem restoration. WL influences plant species in wetlands via the deterioration of the plant root environment which leads to oxygen deficiency that affects plant growth, photosynthesis, respiration, and other metabolic processes. A suitable plant species was determined according to tolerance to WL during wetland vegetation recovery activities. Thus, two tree species (Cleistocalyx operculatus and Syzygium jambos) that showed a certain waterlogging tolerance were chosen to study their behaviors in different planting model and environmental conditions. Given that interspecific relationship should be considered during plant community construction, the eco-physiological adaptable mechanisms between these woody plants under well-watered condition and waterlogging stress were explored. Results showed that both species were waterlogging-tolerant species due to their ability to adapt to submergence conditions for 120 days. Moreover, C. operculatus possessed stronger tolerance to waterlogging stress because of a significant adventitious roots biomass accumulation. A competitive relationship was found between C. operculatus and S. jambos under well-watered condition, and C. operculatus showed better growth performance benefited from morphological responses (plant height, number of blade and leaf area) and endogenous hormone variations. In comparison, S. jambos suffered some negative effects when the well-watered mixed planting was used. However, the competitive relationship under well-watered condition was transformed into mutualistic relationship under waterlogging stress. The mixed planting under waterlogging condition significantly improved the tolerance of C. operculatus and S. jambos to waterlogging stress, compared with the monoculture., Especially, S. jambos showed improvements in root length, root surface area, and redox equilibration between lower levels of relative conductivity, malondialdehyde, and and had increased levels of non-enzymatic antioxidant components, such as reduced glutathione and soluble proteins. The interspecific relationship between C. operculatus and S. jambos was altered by waterlogging stress, and both showed improved tolerance to waterlogging stress. This study can provide a glimmer of light on suitable plant species selection and plant community construction during the revegetation activities in wetland zones. C. operculatus and S. jambos represent potential candidates in wetland restoration in a mixed planting model.

Ecological Service Value Tradeoffs: An Ecological Water Replenishment Model for the Jilin Momoge National Nature Reserve, China.

Wetlands as an important ecosystem type have been damaged in recent years and restoration of wetland ecosystem functions through ecological water replenishment is one of the important ways. The present study involved the construction of a novel ecological water replenishment model for Jilin Momoge National Nature Reserve (JMNNR) using the interval two-stage stochastic programming (ITSP) method. Breaking down traditional economic models that often sacrifice environmental benefits, the model aims to replenish the ecological water in JMNNR, allocate the ecological water resources scientifically, restore the wetland function of the reserve, improve the functional area of the reserve, enhance the net carbon sequestration capacity of the reserve, and complete the reconstruction of the ecosystem, while considering the ecological service value (ESV) of the reserve to achieve a joint increase in the ecological and economic benefits. The ITSP model constructed in the present study overcame the limitation that the original project recommendation was a single recommended value, and the results are presented in the form of intervals to improve flexibility in decision making to allow the individuals responsible for under-taking decisions to bring focused adjustments according to the actual decision-making conditions and increase the selectivity of the decision-making scheme. The present report discusses the construction of an ITSP model for the ecological water replenishment of JMNNR in an attempt to effectively improve both economic benefits and ecosystem restoration of the reserve, achieve the reconstruction of the JMNNR ecosystem, and provide a selective decision space for the key decision-makers to formulate and optimize the project operation and the management plan. The use of the ITSP model as a pre-procedural basis for the implementation of the project and the simulation of the effects of the implementation of the project can effectively avoid the decision limitations that exist when carrying out the project directly. The ITSP model constructed in this paper can also be used as a theoretical guide for water replenishment projects in different areas of the world, and the model parameters can be reasonably adjusted to achieve better results when used according to the actual local conditions.

Research progress and development trend of coastal wetland restoration in greater bay areas

• We explored the progress and development trend of coastal restoration in greater bay. • Restoration methods are mainly based on biotic, hydrologic, and chemical processes. • Functional processes are critical to the maintenance of coastal ecosystem functions. We explored the potential for functional processes maintenance principles to be applied in coastal restoration. Greater bay areas are located in the transition zone between land and sea. Coastal wetlands play a key role in the ecological environment construction of greater bay areas. Due to the dual effects of high-intensity human activities and climate change, coastal wetlands in greater bay areas have suffered varying degrees of damage, including reduced area, habitat degradation, and impaired ecological functions. However, the research progress and development trend of restoration of damaged coastal wetland ecosystems has not yet been revealed, and the application theory of functional processes in coastal restoration is still unclear. Based on extensive literature research, our study reviewed the mechanisms and types of coastal wetland ecosystem restoration in greater bay areas. Coastal wetland ecosystem restoration technologies and methods are mainly based on the biological, hydrological, and chemical processes in greater bay areas. The current research progress and existing deficiencies of coastal wetland ecosystem restoration in greater bay areas are clarified. Combining years of research background in the coastal wetland field, focusing on the importance and criticality of coastal wetland functional processes to maintaining ecosystem functions, the main future research trends are proposed, which will solve the principal theory facing the restoration of coastal wetland ecosystems in greater bay areas. Our study will promote the application of new concepts and new techniques of coastal wetland restoration nationwide, and improve the overall level of ecological restoration in coastal wetland.

Pioneer salt marsh species Scirpus mariqueter disperses quicker in summer with seed contribution from current and last year

Salt marshes are widely considered to be the most valuable ecosystems for their important ecosystem services. Considering that pioneer species often spread rapidly over large areas in a short time under suitable conditions, there is a pressing need to understand their rapid dispersal (seed and seedling) mechanism and post-germination growth and fate. Based on remotely sensed images, field surveys and manipulative experiments, the rapid dispersal mechanism of S. mariqueter, one of the key native pioneer species at the Yangtze Estuary, was investigated. The results showed that (1) the average seaward expansion rate (the area of new dispersal in current year to that of the last year) of S. mariqueter was about 61% (maximum 181.7%) from 2013 to 2019 in Chongming Dongtan, and the expansion area in summer (August) was twice as large as that in spring (May). (2) Seeds from current year facilitate the dispersal of S. mariqueter with the contribution rate up to 27%, in addition to the seeds from last year. (3) The special germination regime of leaves sprouting prior to roots largely enhanced the buoyancy of the newly germinated seedlings, allowing them to have a potential long-distance dispersal. (4) The total event processes, including seed soaking and germination (7 days), root taking (2 days), forking (6 days), were completed within 15 days, which is highly consistent with the spring tidal cycle. These results illustrated important mechanism for quick expansion of pioneer salt marsh species at a large scale. It suggests that the successful seedling establishment of salt marsh species are closely linked to windows of opportunity (WoO), which provide scientific support for the conservation and restoration of coastal wetland ecosystems.

Integrating two aspects analysis of hydrological connectivity based on structure and process to support muddy coastal restoration

With social and economic development and population growth, a series of human activities have intensified the destruction and degradation of muddy coastal wetlands, thus it is necessary to strengthen their protection and restoration. Hydrological connectivity is a basic condition for the existence and restoration of wetland ecosystems. This study selected the northern buffer zone of Yancheng National Nature Reserve (YNNR) as the research area. Combining field survey data with GF-2 remote sensing data, hydrological structure and process connectivity were integrated to evaluate the hydrological connectivity through internal and land-sea aspects. On this basis, the restoration priority area and the easy restoration area were determined by hot spot analysis and minimum unit of restoration. Our results showed that: 1) the hydrological connectivity within the region was great, with most of the total area. Land use types had a greater impact on the hydrological connectivity, and the hydrological connectivity of the farming pond area were generally higher than for farmland; 2) the sea-land hydrological connectivity decreased from the sea to the land, which was vertical with the coastal seawall, but the rate of change varied.; 3) the hydrological connectivity hotspot analysis showed that the site of the level 1 priority restoration was almost the same as the salt water dominant restoration area; the priority level 2 was in the freshwater dominant restoration area, accounting for 8.87% of the area; 4) the easy-to-restore areas were mainly distributed in the priority restoration areas of level 1–3, with an area of 11.7 km2, accounting for 6% of the study area. These research results can provide a better scientific basis for regional muddy wetland restoration planning activities.