Disposal of Rural Domestic Sewage in Ecological Wetland System

Pollution brought by rural domestic sewage has become increasingly serious, so it is imperative to fi gure out economical and efficient solutions. On the basis of comparison between rural domestic sewage treatment means in China and abroad, actual conditions of countryside, current situation and features of domestic sewage, this paper adopted the compound ecological wetland system consisting of anaerobic and aerobic units, ecological floating bed and artifi cial wetland, so as to remove nitrogen and phosphorus efficiently, achieve the goal of low operation and construction cost and less land use.

Study on ecological fragility of wetlands in Sanjiang Plain

As the largest inland freshwater wetlands in China. Sanjiang Plain plays an important role in environmental protection from local scale to global scale. However, due to the fragility of the wetland ecosystems and the environmental disturbances on them caused by natural disasters and human activities, loss and degeneration of wetlands in this area are considerable. Characteristics and reasons of wetlands' ecological fragility in Sanjiang Plain are analyzed and then the evaluation method and index system on ecological fragility of wetlands in Sanjiang Plain are presented. The result of the evaluation shows that the wetlands' ecological fragility in Sanjiang Plain is serious. The value of this method and index system is also discussed in the paper.

Dynamic Assessment on Ecological Frangibility of the Caohai Wetland in Guizhou Province

By analyzing current situation of the Caihai Wetland, combining with "3S" technology, theory of ecosystem health, landscape ecology theory, applying the model of Pressure–State–Response, this paper assessed dynamic changes of ecological frangibility of the Caohai Wetland in Guizhou in 1992, 2000 and 2013. The results showed that the wetland ecosystem had sound principal functions, but also witnessed different degrees of degradation. The ratio of basic complete ecosystem landscape area in the Caohai Wetland reduced from 70.56% in 1992 to 66.26% in 2013, and the ratio of destructed landscape area increased from 12.11% in 1992 to 13.38% in 2013.

The Countermeasures of Ecological Rehabilitation in Jinghe National Wetland Park

By analyzing the ecological status of Jinghe National Wetland Park of Qinggang,Heilongjiang,the countermeasures of ecological rehabilitation in Jinghe National Wetland Park are put forward.

Influence of water conservancy project on runoff in the source region of the Yellow River and wetland changes in the Lakeside Zone,China

The source area of the Yellow River(SAYR),located above the Huangheyan hydrological station,is important for ecological preservation and water source conservation in the Yellow River Basin.In this area,the impact of water conservation projects on the hydrology and the ecological environment is pivotal in protecting water resources and alpine vegetation ecosystems.This study investigates the impact of the Yellow River Source Hydropower Station on the runoff and ecological evolution of the SAYR,along with the underlying mechanism,using extensive datasets encompassing long-term meteorological,hydrological and remote sensing data from various time periods.Results show that,over the long term,precipitation is the primary factor driving runoff variations in the SAYR.Nevertheless,from 1990 to 2020,there is a notably inconsistent relationship between precipitation and runoff.After the completion of the Yellow River Source Hydropower Station in 2001,the water level of Eling Lake experienced and elevation of 2–3 m,leading to a gradual recovery of runoff.In addition,the basin's water balance shifted from a negative to a positive equilibrium,oscillating with changes in lake water levels.Consequently,the overflow zone of the Tangchama alluvial–proluvial fan in the upper reaches of the lakeshore shifted by 500 m,and marsh wetlands expanded by 20.78 km^(2).The increased storage of lakes and groundwater in the SAYR is the key controlling factor for the runoff recovery,changes in the basin's water balance,and enhancements in lakeshore vegetation ecology.Under the geological background of the Qinghai–Tibet Plateau's upliftment and intensified upstream river erosion,the basin experienced a substantial water imbalance due to declining discharge base levels,which is the most critical factor behind runoff attenuation in the SAYR towards the end of the 20th century.The construction of the hydropower station objectively raised the drainage base level of the basin,thereby positively contributing to the preservation of water balance,runoff stability,and the enhancement of swamps and wetlands along the lakeshore.

The influence of three mangrove species on the distribution of inorganic nitrogen and phosphorus in the Quanzhou Bay estuarine wetland soils

This study aims to investigate the effects of region and three regional dominated mangrove species(Avicennia marina, Aegiceras corniculatum and Kandelia candel) on the distribution of inorganic nitrogen and phosphorus. Measurement of the inorganic nitrogen and phosphorus and enzymatic activities was carried out in soils covered by three mangrove species in the Quanzhou Bay estuarine wetlands, a typical coastal wetland in China.Species with a higher biomass in upstream and midstream absorb more nitrogen from soils, and the retention of the available phosphorus in the soils of different regions causes the regional variation of phosphorus. In areas dominated by A. marina, nitrate nitrogen is lower while available phosphorus is higher. Meanwhile, nitrate nitrogen and available phosphorus are higher in the soils covered by K. candel.Moreover, all three species affect the elemental and enzymic stoichiometry. The mangrove species influences the diversity of the elemental and enzymic stoichiometric relationship through differential microenvironments, which induce the biodiversity of wetland ecosystems. Thus, this study may facilitate a better understanding of the transformation ability of mangroves to nitrogen and phosphorus and will therefore be beneficial for providing a basis for the ecological restoration of estuarine wetlands.

Effects of Wetland Utilization Change on Spatial Distribution of Soil Nematodes in Heihe River Basin, Northwest China

The first account of the effects of wetland reclamation on soil nematode assemblages were provided, three sites in Heihe River Basin of Northwest China, that is grass wetland(GW), Tamarix chinensis wetland(TW) and crop wetland(CW) treatments, were compared. Results showed that the majority of soil nematodes were presented in the 0–20 cm soil layers in CW treatments, followed by in the 20–40 cm and 40–60 cm layers in GW treatments. Plant-feeding nametodes were the most abundant trophic groups in each treatment, where GW(91.0%) > TW(88.1%) > CW(53.5%). Generic richness(GR) was lower in the TW(16) than that in GW(23) and CW(25). The combination of enrichment index(EI) and structure index(SI) showed that the soil food web in GW was more structured, and those in TW was stressed, while the enrichment soil food web was presented in the CW treatment. Several ecological indices which reflected soil community structure, diversity, Shannon-Weaver diversity(H′), Evenness(J′), Richness(GR) and modified maturity index(MMI) were found to be effective for assessing the response of soil namatode communities to soil of saline wetland reclamation. Furthermore, saline wetland reclamation also exerted great influence on the soil physical and chemical properties(p H, Electric conductivity(EC), Total organic carbon(TOC), Total nitrogen(Total-N) and Nitrate Nitrogen(N-NO3–)). These results indicated that the wetland reclamation had significantly effects on soil nematode community structure and soil properties in this study.

Application of pressure-state-response approach for developing criteria and indicators of ecological health assessment of wetlands:a multi-temporal study in Ichhamati floodplains,India

Background Tropical floodplain wetlands are among the most disturbed and intensively harvested ecosystems.Their sustainable management is often hindered due to the lack of comprehensive,coherent,and standardized assessment frameworks of wetland ecological health(WEH).In this study,a set of appropriate criteria and indicators(C&I)of WEH assessment was developed and tested on seven wetlands of River Ichhamati,eastern India.Methods Based on the pressure-state-response(PSR)approach,evaluation indicators representing ecological,socio-economic,and institutional sustainability issues of floodplain wetland systems were either selected or formulated through literature survey and stakeholder consensus.Weights of indicators were assigned by the entropy weighting method and then used in the Technique for Order of Preference by Similarity to Ideal Solution model to determine the Euclidean distances of each wetland from the positive ideal solution and negative ideal solution.Subsequently,a comprehensive wetland ecological health index(CWEHI)was constructed from these distances to portray the condition of any PSR system component in a wetland under a fivefold classification scheme,namely‘excellent health’(CWEHI≥0.81),‘good health’(0.61-0.80),‘moderate health’(0.41-0.60),‘weak health’(0.21-0.40),and‘morbid’(≤0.20).Results The developed C&I set contains 8 criteria and 38 indicators under pressure component,7 criteria and 49 indicators under state component,as well as 4 criteria and 18 indicators under response component.When applied in 2016 and 2022,it was found that the Panchita and Aromdanga wetlands were continuously in weak and morbid health status,while the Madhabpur wetland always showed an excellent or good status for all components.Health of other wetlands oscillated between moderate and morbid health across assessment years and system components.Conclusions The developed C&I set was found to be a flexible,holistic,and refined framework that could be applied elsewhere in similar assessments with minor indicator-level adjustments.The present assessment inferred that agriculture-dominated wetlands were more affected by amplified environmental pressure than fishing-dominated wetlands.Absence of persistent water flow from main river channel,wide-spread jute-retting,agriculture-induced eutrophication,proliferation of aquatic weeds were identified as the major causes of rapid ecological deterioration.

Using miniaturized GPS archival tags to assess home range features of a small plunge-diving bird:the European Kingfisher(Alcedo atthis)

Background:The European Kingfisher(Alcedo atthis)is a small plunge-diving bird,today considered a species of conservation concern in Europe given its rapid population decline observed across the continent.We implemented a pilot study aimed at providing first data allowing to:(1)assess home range features of the European Kingfisher for populations with unevenly distributed feeding habitats;(2)define conservation implications for habitats exploited by such populations;and(3)evaluate possibilities for developing GPS tracking schemes dedicated to home range stud-ies for this species that could be possibly applied to other small plunge-diving birds.Methods:In 2018 and 2019,we equipped 16 breeding European Kingfishers sampled within the marshes of the Gironde Estuary(France),with miniaturized and waterproof GPS archival tags deployed with leg-loop harnesses(total equipment mass=1.4 g;average bird mass=40.18±1.12 g).Results:On average,we collected 35.31±6.66 locations usable for analyses,without a significant effect on bird body condition(n=13 tags retrieved).Data analyses highlighted rather limited home ranges exploited by birds(aver-age=2.50±0.55 ha),composed on average by 2.78±0.40 location nuclei.Our results also underscore:(1)a rather important home range fragmentation index(0.36±0.08);and(2)the use by birds of different types of small wetlands(wet ditches,small ponds or small waterholes),often exploited in addition to habitats encompassing nest locations.Conclusions:Our study reveals interesting GPS tracking possibilities for small plunge-diving birds such as the European Kingfisher.For this species,today classified as vulnerable in Europe,our results underline the importance of developing conservation and ecological restoration policies for wetland networks that would integrate small wet-lands particularly sensitive to global change.

Fluorescence Properties of Submerged Macrophytes in Nanjishan Wetland,Southern Poyang Lake

We used a FluorCam portable chlorophyll fluorescence imaging system to measure QY-max （the maximum light quantum yield, Fv/Fm, the largest light quantum efficiency of PS Ⅱ） of submerged plants in wetlands of Baisha Lake and Changhu Lake, Jiangxi Nanjishan Wetland National Nature Reserve, in winter 2013. Specifically, we measuredΦPS Ⅱ （PS Ⅱ actual quantum efficiency）, qP （photochemical quenching） and corresponding fluorescence images. Using the visual method and sampling sites method to obtain coverage, richness and abundance of submerged plants, and determined nutrient levels in water. The results show that the QY-max ofHydrilla verticillata andVallisneria natans in Baisha Lake ranged from 0.48 to 0.68 and 0.52 to 0.71, respectively; theΦPS Ⅱ of these two species ranged from 0.32 to 0.58 and 0.20 to 0.46, respectively. The two plants had similar photosynthetic efifciency. The QY-max ofNymphoides peltatum andV. natans in Changhu Lake ranged from 0.66 to 0.77 and 0.19 to 0.68, respectively; theΦPS Ⅱ of these two species ranged from 0.26 to 0.48 and 0.22 to 0.43, respectively. The observed higher photosynthetic efifciency of N peltatum suggests it is more likely to become the dominant species. In Baisha Lake, the frequency of occurrence of plants was：H. verticilata, 90%;V. natans, 93.3%;Najas minor26.7%, andPotamogeton francheti10%. In Changhu Lake, the frequency of N. pel-tatum was 86.7%,V. natans was 16.7%, andN. minor was 56.7%. The overal frequency of submerged plants living in Baisha Lake was much higher than that of submerged plants living in Changhu Lake, with different species dominating the two lakes. According to comprehensive analysis and comparison of trophic levels, biodiversity and photosynthetic fluorescence characteristics in the two lakes, eutrophication of Baisha Lake was higher than for Changhu Lake; andH. verticillata andV. natans were the dominant species, with similar photosynthetic activity. Conversely, in Changhu Lake,N. peltatum andV. natans were the dominant species, but the photosynthetic activity of N. peltatum was higher thanV. natans. Differences in eutrophication levels in different water bodies in the Nanjishan Wetland and differing ecological niches of submerged plant species are characteristic of this system.