Wetland Development Research Articles

Phenotypically Induced Intraspecific Variation in the Morphological Development of Wetland and Stream Galaxias gollumoides McDowall and Chadderton

The hypothesis that contrasting hydrology induces divergent intraspecific phenotypic plastic responses in non-migratory freshwater fish was investigated. Morphologies of wetland and stream Galaxias gollumoides from South Island, New Zealand, at different stages of ontogeny, were examined. Phenotypic responses were tested for in a 2 × 2 factorial laboratory based controlled reciprocal transplant experiment with flow (current or no current) and source habitat (wetland or stream), as treatments. There was a shift in the overall head morphology of wetland current treatment G. gollumoides away from the wetland no current treatment, and toward the stream current treatment, demonstrating convergence in head morphology in the presence of flow of wetland and stream sourced captive G. gollumoides. Morphologies of captive reared G. gollumoides were also compared to developmental trajectories of morphological characters during the ontogeny of field reared first year, and adult conspecifics. In combination, experimental and field results support the hypothesis, finding habitat hydrology to be the potential mechanism inducing and maintaining intraspecific morphological divergence in G. gollumoides. Recognition of this mechanism inducing morphological divergence between populations also aids the taxonomic description of long genetically recognised lineages of co-members of the Galaxias vulgaris species complex.

Two-year performance of single-stage vertical flow treatment wetlands planted with willows under cold-climate conditions

Climate-related issues constitute an important obstacle for the development of treatment wetland (TW) applications in regions with freezing winter temperatures. The aim of the present study was to evaluate the efficiency of a new configuration of TWs based on the vertical flow (VF) configuration. The proposed TWs system is planted with a willow species (Salix miyabeana SX67) and including design adaptations for cold climate operation. Two different flow modes for winter-time operation were proposed: percolated and saturated with continuous artificial aeration. The pilot-scale systems were tested with municipal wastewater, at an organic loading ranging from 5 to 20 g CBOD5 m−2 d−1.The pilot TWs were successfully operated for 22 months despite freezing winter temperatures reaching as low as −32 °C. Willow development was normal, with evapotranspiration ranging from 19 to 23 mm/d in July 2017 for the pilot TWs at an organic loading of 10 g CBOD5 m−2 d−1. Organic matter removal efficiency was high for all pilot TWs, with an average 91% COD and 81% TSS removal. Nitrification was essentially complete during the summer period and remained high for pilot TWs operated under percolating flow mode in winter but was lower for the saturated flow mode, probably due to insufficient air supply. Our study confirms the successful application of a modified version of VF TW in regions with freezing air temperatures.

Tidal Marsh Restoration at Poplar Island I: Transformation of Estuarine Sediments into Marsh Soils

Dredged materials from navigation channel maintenance represent a potentially valuable resource for wetland creation and restoration. In the northern Chesapeake Bay, fine-grained sediments from Baltimore Harbor approach channels are transported by barge southward for creation of wetlands on the site of an eroded island. High concentrations of ammonium, soluble reactive phosphorus, dissolved iron, and iron sulfide minerals in channel deposits are altered by the transport and drying of these materials prior to wetland development. The oxidation of iron sulfide minerals results in low pH, with the initiation of tidal inundation removing sulfuric acid from near-surface soil horizons and moderating the soil pH. Despite the loss of ammonium during dewatering and soil processing, the resultant soils retained high concentrations of dissolved and adsorbed ammonium. Iron-associated inorganic phosphorus represented a large pool of potentially labile phosphorus and along with the high ammonium, resulted in high nutrient concentrations for plant growth. Combined with results on plant growth presented elsewhere, these data suggest that fine-grained dredged materials from non-contaminated environments are well suited for the creation of tidal wetlands after placement and seasoning 1–2 years.

Valuation of Ecosystem Services from an Important Wetland of Nepal: A Study from Begnas Watershed System

Determining the economic value of wetlands is essential while creating sustainable wetland development plans and market-based ecological protection strategies. This paper studies the value of Begnas Watershed System by assessing the economic values of its selective ecosystem servicees. We conducted household surveys, multiple focus group discussions, stakeholder consultation, indepth interviews and used a combination of market and non-market based valuation methods like market price method, travel cost method, revealved price method, contingent valuation method, and benefit transfer method to determine the value of ecosystem services of the Begnas Watershed System. This study discovered that the economic benefit generated from the wetland was worth US 3.91 million per year, equivalent to US 650.67 per household and US$ 799.79 per hectare. The direct non-consumptive (recreational) service was the most beneficial service holding about 85% of the total value. This research study concludes that the Begnas Watershed System is economically beneficial for the local communities living in or close to the watershed and is worth the investment in lake restoration projects. This results from this study will serve as an important tool for policymakers and stakeholders during the formulation of management plans for the wetland's sustainability.

Aquatic macrophytes in Ethiopian Rift Valley Lake Koka: Biological management option to reduce sediment loading

Nowadays, due to deforestation, poor soil management and improper farming techniques, reservoir and lake sedimentation is a serious problem in Ethiopia. Despite the severity of the problem, there is no documented study on the use of macrophytes as a biological management option for sediment loading. A sediment trap field experiment was conducted from July to September 2017 to assess the efficiency of macrophytes in reducing sedimentation problem in Lake Koka. During the study period (90 days) on average a total of 1140 g DW m−2 sediment was deposited at the vegetated stations and 336 g DW m−2 at the open water site. The corresponding values for resuspension were 906 g DW m−2 and 1680 g DW m−2, respectively. Compared with the non-vegetated area, all macrophytes significantly facilitated sedimentation and reduced resuspension (P < 0.05). The order of the macrophytes in their sediment trapping efficiency was Echinochloa stagnina>Typha angustifolia > Eichhornia crassipes = Leptochloa caerulescens and the corresponding order for restraining resuspension was T. angustifolia > E. stagnina >E. crassipes = L. caerulescens. Generally, E. stagnina and T. angustifolia were better in trapping sediment and preventing resuspension. Development and maintenance of wetlands with these aquatic macrophytes may be an effective management tool for reducing the sediment load on Lake Koka, but would need further studies on the effect of wind velocity and direction on their efficiency.

Ecological development of coastal wetland in north coast of Hangzhou Bay of Shanghai

Taking the north coast of Hangzhou Bay of Shanghai as an example, this paper studies the ecological development model of coastal wetland under the combination of the time background and environmental conditions. In this paper, the coastal wetlands in north coast of Hangzhou Bay of Shanghai were divided into 4 types according to needs, including tourism park, tidal flat reservoir, reed tidal flat wetlands, muddy coastal wetlands. Through the use of case studies, the cases of similar site conditions or environmental issues were summarized, so as to be 4 types of coastal wetlands to find more suitable ecological development measures to provide reference for decision makers and builders.

Research On Wetland Ecological Planning Of Jiukenghe Reservoir In Zhaoqing

The article takes Zhaoqing Jiukenghe Reservoir as the research object. According to the land use planning of Zhaoqing City, the rural construction around the Jiukenghe Reservoir in Dinghu District of Zhaoqing and the development of the Jiulong Lake tourist area have caused potential pollution threats to the water source protection area. This paper mainly uses GIS ecological planning methods to study the analysis of wetland development potential of water sources, formulate wetland protection plans, delineate wetland core protected areas, restore wetland ecosystems, delineate ecological buffers, and cultivate wetland conservation forests. It also needs to control pollution sources in village construction and tourism practices, cultivate multi-level natural landscapes of aquatic plants, provide good habitats and breeding habitats for wild animals and plants, enhance water purification and water conservation functions, and create ecological landscapes in natural countryside.

Constructed wetland technology and its application in water quality control of south lake system

Constructed wetland technology is widely used. It has significant effect in the removal of eutrophication factor N, P. From the wetland development and cleansing mechanism of The paper introduces the constructed wetland technology in the use of water treatment of lake form the development of the constructed wetland and the derergency mechanism. The paper especially introduces its application in water quality control of south lake system. In order to analyze the total phosphorus load, it analyze the annual water diversion by the water balance. It discusses the design points of the constructed wetland used in the south lake system. Finally, the outlook of the research in the constructed wetlands and it’s application in eutrophic lake pollution control.

Relationship between hydroclimatic variables and reservoir wetland landscape pattern indices: A case study of the Sanmenxia Reservoir wetland on the Yellow River, China

Reservoir construction has led to the development of numerous wetlands, and these wetlands play an important role in global environmental change. In this paper, we investigate the relationship between reservoir wetlands and hydroclimatic variables. We used the MODIS land cover product to extract the wetland area of the Sanmenxia Reservoir, China. Then, various indices of reservoir wetland landscape patterns were calculated. Principal component analysis was performed to build the Sanmenxia Reservoir wetland comprehensive landscape pattern index (CLPI) to depict the changes in Sanmenxia Reservoir wetlands from 2001 to 2013. Pearson correlation analysis was used to assess their relationship. The following results were obtained. Firstly, the Sanmenxia Reservoir wetland area considerably declined and the landscape heterogeneity decreased from 2001 to 2013, especially in 2004. Secondly, the CLPI is significantly negatively correlated with annual runoff and significantly positively correlated with annual sediment discharge, annual average water level and annual shallow groundwater table in Sanmenxia Reservoir regions. Additionally, due to the decline in the reservoir wetland area, the values of Shannon’s diversity index and Simpson’s diversity index decreased in the study area. Therefore, the study suggests that maintaining a stable and healthy reservoir wetland area should be the focus of ecological reservoir management.

Wetland expansion on the continental shelf of the northern South China Sea during deglacial sea level rise

To identify environmental causes for past changes in vegetation in subtropical East Asia, we present carbon isotope compositions of plant-wax n-alkanes and provide estimates of the C4-plant contribution across the past four glacial terminations and interglacials, based on cores recovered from the northern South China Sea. Our results show a comparable C4-plant contribution between the Last Glacial Maximum (LGM) and the Holocene. An increase of the C4-plant contribution by 15–20% is found for Terminations IV, II and I relative to subsequent interglacial peaks, coeval with an expansion of Cyperaceae and Poaceae. In contrast, Termination V reveals a lower C4-plant contribution than Marine Isotope Stage (MIS) 11c. The data exhibit a long-term trend, with a stepwise increase of the C4-plant contribution across interglacials MIS 11c, 9e, 7e and 1. We suggest that no substantial changes in humidity levels over glacial-interglacial cycles occurred facilitating a similar C3/C4-plant ratio for the LGM and the Holocene. Instead, deglacial sea-level rises caused an extensive development of floodplains and wetlands on the exposed continental shelf, providing habitats for the spread of C4 sedges and grasses. The progressive subsidence of Chinese coastal areas and the broadening of the continental shelf over the late Quaternary explains the nearly absence of C4 plant occurrence during Termination V and a gradual increase of the C4-plant contribution across interglacial peaks. Taken together, changes in coastal environments should be considered when interpreting marine-based vegetation reconstructions from subtropical Asia.

Spatial variability and agglomeration of soil salinity in Minjiang estuary wetland, Southeast China

Understanding the spatial variability and agglomeration of soil salinity is of great significance for the sustainable development of estuarine wetland. Landsat 8 OLI remote sensing image, digital elevation mode and soil surface samples of Minjiang estuary wetland of Fuzhou were used as the data sources. The correlation analysis and principal component analysis were combined to select significant environmental variables and to reduce their dimensions. We analyzed the spatial variability of soil salinity with support vector regression ordinary kriging model (SVROK) and regression kri-ging model (RK), and quantified spatial agglomeration of soil salinity by the spatial autocorrelation analysis. The results showed that three principal components (PCs) extracted by the principal component analysis could explain at least 85% of the total variance in the original dataset and reflected the comprehensive information of vegetation cover, soil properties and topography. Both soil salinity and its residuals were affected by structural factors and random factors. The SVROK model based on principal component (PCs) as input variables can more accurately reflect the spatial variability of soil salinity, with a trend of "higher in the north and lower in the south". The Moran's I of soil salinity was more than 0.5, with significant positive spatial autocorrelation and a higher spatial aggregation degree, displaying the spatial agglomeration characteristics of "high value agglomeration, high value widespread, high value surrounded by low value".

Nitrogen and Phosphorus Storage of Baiyangdian Wetland influences and Threats on the ecology factors

Baiyangdian is the north China plain, the largest and most typical freshwater lake wetland, has important effects on the ecological environment in north China, called the kidney of north China, therefore, strict protection of Baiyangdian wetland is of great practical significance. This Baiyangdian wetland’s study aims to understand the different ecological communities and wetland ecological health assessment in wetland system, and to analyze and study the water quality and biodiversity of Baiyangdian wetland. Then through analyses of nitrogen and phosphorus storage, advantages and disadvantages of Baiyangdian among the wetland are clarified. Finally, based on the successful experience of some other wetland, some suggestions on the future development of wetland are put forward for Baiyangdian .

Hard or soft flood adaptation? Advantages of a hybrid strategy for Shanghai

Flood risk is expected to increase in coastal cities, particularly in Asian megacities such as Shanghai. This paper presents an integrated modeling framework to simulate changes in the flood risk in Shanghai and provide a cost-benefit analysis of multiple adaptation strategies used to reduce risk. The results show that the potential flood risk will increase dramatically as a result of sea level rise, land subsidence, and socioeconomic development. By 2100, the expected annual damage could reach 0.8% (uncertainty range: 0.4%–1.4%) of local GDP under an optimistic emission scenario (RCP4.5), compared to the current value of 0.03%. All of the adaptation strategies can effectively reduce the flood risk under the current conditions and those in 2050. In contrast to the ‘hard’ flood protection strategies (i.e., storm-surge barriers and floodwalls), the ‘soft’ strategies (i.e., building codes and nature-based measures) cannot substantially reduce the flood risk in 2100. However, the soft strategies can play a critical role in reducing the residual risk resulting from the hard strategies. A ‘hybrid’ strategy combining a storm-surge barrier, wet-proofing, and coastal wetland development outperforms both hard and soft strategies in terms of low residual risk and high benefit/cost ratio. Additionally, the hybrid strategy can also enable a larger reduction in casualties. These findings imply that managing flood risk is more than the use of single adaptation measures. The methodology developed in this paper can enlighten Shanghai and other coastal cities on an economically and socially feasible adaptation strategy in an uncertain future.

Temperate coastal wetland near-surface carbon storage: Spatial patterns and variability

Carbon mitigation services provided by coastal wetlands are not spatially homogeneous, nevertheless are commonly described on the basis of vegetation distribution within the intertidal zone. Distribution of mangrove and saltmarsh varies in response to frequency of tidal inundation, resulting in environmental gradients in edaphic factors that influence vegetation structure, and subsequently affect sedimentary carbon additions by vegetation and carbon losses by decomposition. Current sampling approaches and reporting do not adequately account for variability of carbon storage within a wetland, and assessments need to capture spatial variation associated with carbon storage to improve estimates of potential carbon mitigation services by natural ecosystems. This study quantifies the variation in near-surface carbon storage (i.e. upper 30 cm) across an intertidal gradient using a stratified sampling approach that recognises vegetation structure. Vegetation distribution and structure, as well as sedimentary controls on carbon content, explained variation in carbon storage. Saltmarsh near-surface carbon storage varied considerably between structural form. This was less evident for mangrove structural forms (i.e. tall, shrub, dwarf), which may be due to mangrove roots extending to depths beyond 30 cm. Sedimentary characteristics correlated with carbon content, demonstrating considerable influence on near-surface carbon storage within a wetland. The principal finding of this study was that variation within a wetland corresponds to the variation between sites. Stable carbon isotopes offer a means to identify previous vegetation contributions to sediment, associated with an earlier stage of wetland development, likely reflecting previous environmental conditions. A stratified sampling approach that recognises vegetation structure provides the capacity to account for variability of carbon within a wetland that is inadequately described by current sampling protocols.

АДАПТАЦИЯ СОСНЫ (PINUS SYLVESTRIS) К СОВРЕМЕННЫМ ЭКОЛОГИЧЕСКИМ РЕАЛИЯМ В БЕЛОРУССКОМ ПОЛЕСЬЕ

The results of a study of the current state of pine (Pinus sylvestris) in the Belarusian Polesie after the completion of reclamation development of swamps and wetlands for agricultural purposes are shown. The problem of its adaptation to the changed hydrogeological realities of a semihydromorphic sand edaphotope in changing climatic conditions has become particularly acute. The maximum, average and minimum tree-ring growth of modern generations of pine in the Belarusian Polesie was used to identify its adaptive abilities. It is proved that the adaptation of pine trees to changing climatic conditions after the completion of drainage reclamation resulted in a decrease in tree-ring growth in the second half of the twentieth century and in the beginning of the twenty-first century. It was found that sensitive to the variability of the conditions of humidification of the semihydromorphic edaphotope, both by atmospheric precipitation and ground water, blueberry pine forest demonstrates greater adaptive adaptability to the changed soil-ground water factor after drainage reclamation in dynamic climatic conditions in the Belarusian Polesie. It was found that the potential for stem mass growth&nbsp; (maximum, average and minimum tree-ring growth) of blueberry pine forest trees is reduced by 1.5 times when the ground water is lowered to 1.6-2.0 m from the initial level of 0.35-0.5 m. It is noted that the May ground water level of 0.6 m is optimal for the stand, although its suppression is not excluded during heavy precipitation.

К вопросу о перспективном направлении развития и анализа разработки труднодоступных переувлажненных лесосек с помощью канатных трелевочных установок в СЗФО РФ

К вопросу о перспективном направлении развития и анализа разработки труднодоступных переувлажненных лесосек с помощью канатных трелевочных установок в СЗФО РФ

The Vascular Flora of Haynes Bottoms Wildlife Management Area, Montgomery County, Tennessee

AbstractHaynes Bottom Wildlife Management Area is a 393-ha state-owned property in Montgomery County, Tennessee. Formerly agricultural, the property was purchased from private ownership in 1996 and includes Cumberland River bottomlands (ca. 180 ha) and level to rolling-sloping uplands (ca. 213 ha). It is managed by the Tennessee Wildlife Resources Agency for wildlife enhancement and public usage. On-going management includes development of wetlands and moist-soil areas primarily for waterfowl in the bottomlands and plantings for agricultural crops and wildlife in the uplands. Based on twenty years of floristic studies, the known vascular flora consists of 605 species, with 153 of these non-natives; four species are elements of conservation concern. A description of the area, analyses of the flora, and an annotated list, are presented.

Evaluation and driving factors of sustainable development of the wetland ecosystem in Northeast China: An emergy approach

The Northeast is one of the regions with the most extensive wetland area in China, which provides important environmental support for social development. However, agricultural reclamation and socio-economic development have changed the land use of wetland ecosystems, resulting in the continuous loss of natural wetland area and affecting the sustainable development of wetlands. In this study, an emergy accounting approach was used to evaluate the sustainable development status of the wetland ecosystem in Northeast China from 1980 to 2015. The results showed that the purchased resources (P) replaced the local renewable resources (R) and the local non-renewable resources (N) as the largest emergy flow after 2000. This change led to a negative development of the emergy indicators. The emergy yield ratio (EYR) decreased from 5.63 to 2.04, the environmental load ratio (ELR) increased from 1.90 to 3.58, and the emergy sustainability indicator (ESI) decreased from 2.96 to 0.57, indicating that the sustainable development of wetlands deteriorated during the study period. Next, the Logarithmic Mean Divisia Index decomposition analysis (LMDI) was applied to decompose the change of the ESI (ΔESI) into 5 driving factors. The results showed that the external pressure factor (Aw/P) had a decisive impact on sustainable development, and the other four factors indicated that renewable resources had a positive contribution to improving sustainable development. Therefore, this study proposes to improve sustainable development from three aspects: firstly, restore or expand the wetland area; secondly, reduce the input of purchased resources; and thirdly, increase the application of renewable resources. Such findings can provide valuable suggestions for the government to better manage wetlands.

Major advances in studies of the physical geography and living environment of China during the past 70 years and future prospects

The natural environment provides material essentials for human survival and development. The characteristics, processes, regional differentiation and forcing mechanisms of the elements of the natural environment (e.g. geomorphology, climate, hydrology, soil, etc.) are the main objects of research in physical geography. China has a complex natural environment and huge regional differentiation and therefore it provides outstanding reserach opportunities in physical geography. This review summarizes the most important developments and the main contributions of research in the physical geography and human living environment in China during the past 70 years. The major topics addressed are the uplift of the Tibetan Plateau and the evolution of its cryosphere, the development of fluvial systems, the acidification of the vast arid region of the Asian interior, variations in the monsoon and westerly climate systems on multiple timescales, the development of lakes and wetlands, the watershed system model, soil erosion, past human-environment interactions, biogeography, and physical geographic zonality. After briefly introducing international research developments, we review the history of research in physical geography in China, focusing on the major achievements and major academic debates, and finally we summarize the status of current research and the future prospects. We propose that in the context of the national demand for the construction of an ecological civilization, we should make full use of the research findings of physical geography, and determine the patterns and mechanisms of natural environmental processes in order to continue to promote the continued contribution of physical geography to national development strategies, and to further contribute to the theory of physical geography from a global perspective.

Impact assessment of Komadugu-Yobe Basin Wetlands Development Initiative Project on farmers livelihood in Jigawa State, Nigeria

Abstract. Umar B, Akpoko JG, Musa MW. 2018. Impact assessment of Komadugu-Yobe Basin Wetlands Development Initiative Project on farmers livelihood in Jigawa State, Nigeria. Bonorowo Wetlands 2: 1-8. This study assessed the impact of the Komadugu-Yobe Wetlands Development Initiative project on income, agricultural production, and standard of living of the people. Primary data were obtained by the use of a structured questionnaire that was administered to 456 respondents comprising the project participants and non-participants. Descriptive statistics, logistic regression, and Chow test were used to analyze the data collected. The findings on the socio-economic variables revealed that the mean age of the participants was 36 years and participants were younger in terms of age distribution, the participants were relatively more educated than the nonparticipants, the participants were also organized in to viable associations under the project, and the average years of farming experience of participants was 15 years while the nonparticipants had about 14 years. It was also found that the majority (85.5) of the participants have not benefitted from credit facilities. The logistic regression analysis shows that the socio-economic characteristics such as age (0.022**), level of education (0.000*), farm size (0.018*), Household size (0.224*), membership of cooperatives (0.022*), and access to credit (0.023**) were the most essential variables that predicted farmer‘s participation in the project. The results of the Chow test show that the F-calculated values on income, crop output, and living standard were higher than the F-tabulated values. It has been concluded that the Komadugu-Yobe Basin Wetlands Development Initiative project had a positive impact on the participants of the project. It is recommended that the project should register more participants as the activities of the project had impacted positively on the lives of the participants, to provide more employment opportunities for the youth in the area. Access to loan happened to be a factor that militates against the enhancement of crop production in the study area. It is recommended that farmers in the study area be linked with financial institutions or government agencies by the project to access loan to boost crop production in the area. Extension activities which play a significant role in extending information to farmers should be revived by the Government as the ratio of an extension agent to farmers is very low, when extension problems are solved, crop production in the area would be enhanced.