Ecological problems and ecological restoration zoning of the Aral Sea

The Aral Sea was the fourth largest lake in the world but it has shrunk dramatically as a result of irrational human activities, triggering the "Aral Sea ecological crisis". The ecological problems of the Aral Sea have attracted widespread attention, and the alleviation of the Aral Sea ecological crisis has reached a consensus among the five Central Asian countries(Kazakhstan, Uzbekistan, Tajikistan, Kyrgyzstan, and Turkmenistan). In the past decades, many ecological management measures have been implemented for the ecological restoration of the Aral Sea. However, due to the lack of regional planning and zoning, the results are not ideal. In this study, we mapped the ecological zoning of the Aral Sea from the perspective of ecological restoration based on soil type, soil salinity, surface water, groundwater table, Normalized Difference Vegetation Index(NDVI), land cover, and aerosol optical depth(AOD) data. Soil salinization and salt dust are the most prominent ecological problems in the Aral Sea. We divided the Aral Sea into 7 first-level ecological restoration subregions(North Aral Sea catchment area in the downstream of the Syr Darya River(Subregion Ⅰ);artificial flood overflow area in the downstream of the Aral Sea(Subregion Ⅱ);physical/chemical remediation area of the salt dust source area in the eastern part of the South Aral Sea(Subregion Ⅲ);physical/chemical remediation area of severe salinization in the central part of the South Aral Sea(Subregion Ⅳ);existing water surface and potential restoration area of the South Aral Sea(Subregion Ⅴ);Aral Sea vegetation natural recovery area(Subregion Ⅵ);and vegetation planting area with slight salinization in the South Aral Sea(Subregion Ⅶ)) and 14 second-level ecological restoration subregions according to the ecological zoning principles. Implementable measures are proposed for each ecological restoration subregion. For Subregion Ⅰ and Subregion Ⅱ with lower elevations, artificial flooding should be carried out to restore the surface of the Aral Sea. Subregion Ⅲ and Subregion Ⅳ have severe salinization, making it difficult for vegetation to grow. In these subregions, it is recommended to cover and pave the areas with green biomatrix coverings and environmentally sustainable bonding materials. In Subregion Ⅴ located in the central and western parts of the South Aral Sea, surface water recharge should be increased to ensure that this subregion can maintain normal water levels. In Subregion Ⅵ and Subregion Ⅶ where natural conditions are suitable for vegetation growth, measures such as afforestation and buffer zones should be implemented to protect vegetation. This study could provide a reference basis for future comprehensive ecological management and restoration of the Aral Sea.

Ecological Restoration Technologies of Urban Artificial Landscape Lakes

Aiming at the problems of water pollution and ecological environment degradation in urban artificial landscape lakes,the ecological restoration technologies of artificial landscape lakes at home and abroad were studied to provide some reference for the ecological restoration of urban artificial landscape lakes in China.

Effects of Ecological Restoration of Mangrove Wetlands Using Native Mangrove Species to Replace Spartina alterniflora: A Case Study in Southern China

Within the expanse of China’s coastline, the invasive alien cordgrass species Spartina alterniflora has caused profound nationwide damage and has emerged as a critical factor contributing to the degradation of mangrove wetlands, especially in the study area in Beihai, Guangxi. However, current treatments for S. alterniflora remain less effective and limited research focuses on the preliminary changes after artificial plantation. A comprehensive approach combining physical interventions with biological control measures has been employed to eradicate smooth cordgrass and facilitate the restoration of native mangrove wetlands. The study involved the periodic monitoring of the growth conditions of mangroves and the biodiversity of avian and benthic organisms, conducted at three to four-month intervals following the artificial plantation with one-year-old seedlings and propagules of native mangrove species Rhizophora stylosa. Results indicated that through the allometric equation, the above-ground biomass of planted seedlings had a ~20 g increase in average but the growth conditions were not significant over an eight-month period. High percentage of important avian species underlined the potential of the study site to serve as a worthwhile habitat and notable seasonal variations were observed in the biodiversity of bird species. Biodiversity indices of bird and benthos species also followed a similar fluctuation and reached a peak in April 2023. This research underscores the initial lack of distinct improvements during the early stages of the ecological restoration project, thorough maintenance, long-term monitoring, holistic considerations on a larger scale would be imperative for ongoing projects in the future.

Ecological Restoration Technology and Carbon Reduction Paths of Abandoned Mines in Zoige Alpine Grassland Area

At first,the ecological restoration technology of abandoned mines is summarized,and the paths and models of mine ecological restoration in Zoige grassland area under the background of carbon neutrality are analyzed.Moreover,the problems and deficiencies in the current research on mine ecological restoration in Zoige grassland area are initially identified,and the future research trend is prospected to provide a reference for the path of carbon reduction by mine ecological restoration in Zoige grassland area and other alpine grassland areas in the future.

Ecological Remediation Measures for Non-point Source Pollution Based on Source-Sink Landscape Theory: A Case Study of Huanghou Basin

The growth of society and population has led to a range of water pollution issues.Among these,non-point source pollution assessment and treatment pose a particular challenge due to its formation mechanism.This has become a focal point and challenge in water pollution treatment research.The study area for this research was the Huanghou basin in Guizhou Province,southwest China.The land use type of the basin was analyzed using remote sensing technology,and water quality data was collected by distributing points throughout the basin,based on source-sink landscape theory.The distribution map of the basin’s source-sink landscape and the results of water quality data accurately and efficiently identified the areas with high risk of non-point source pollution in the western and southwestern residential and agricultural areas of the upper basin.Hence,a strategy of“increasing sinks and decreasing sources”was proposed.The strategy was implemented at both macro and micro levels to address non-point source pollution in the basin using ecological remediation techniques.The work to control karst rocky desertification should continue at a macro level.The rocky desertification area in the basin should gradually transform into grassland and forested land,while increasing the overall area of the sink landscape.Ecological restoration techniques,such as slope planting,riparian zone vegetation restoration,increasing plant abundance,and restoring aquatic plants,can effectively control non-point source pollution at the micro level.Compared to traditional control methods,this remediation strategy focuses on source and process control.It is more effective and does not require large-scale water pollution control projects,which can save a lot of environmental control funds and management costs.Therefore,it has greater research significance and application value.

Spatiotemporal Evolution of Ecological Quality in Alpine Freshwater Lake Nature Reserves in the Past 20 Years

The Caohai Nature Reserve is one of the three major plateau freshwater lakes in China.Since the 1950s,human activities such as land reclamation and population relocation have greatly damaged Caohai.A rapid evaluation of the spatiotemporal evolution trend of the ecological quality of the Caohai Nature Reserve is significant for the maintenance and construction of the ecosystem in this area.The research is based on the Google Earth Engine(GEE)remote sensing cloud computing platform.Landsat TM/OLI images from May to October in five time periods:2000-2002,2004-2006,2009-2011,2014-2016,and 2019-2021 were obtained to reconstruct the optimal cloud image set by averaging the images in each time period.By constructing four ecological indicators:Greenness(NDVI),Wetness(Wet),Hotness(LST),and Dryness(NDBSI),and using Principal Component Analysis(PCA)method to obtain the Remote Sensing Ecological Index(RSEI)for the corresponding years,the spatiotemporal variation of ecological quality in the Caohai Nature Reserve over 20 years was analyzed.The results indicate:①the mean value of RSEI increased from 0.460 in 2000-2002 to 0.772 in 2019-2021,a 67.83%increase,indicating a significant improvement in the ecological quality of the reserve over the 20 years;②from the perspective of functional zoning of the Caohai Nature Reserve,the ecological quality of the core area showed a degrading trend,while the ecological quality of the buffer zone and experimental zone significantly improved;③with the implementation of ecological restoration projects,the ecological quality of the reserve gradually recovered and improved from 2014 to 2021.The trend of RSEI value changes is well correlated with human interventions,indicating that the PCA-based RSEI model can be effectively used for ecological quality assessment in lake areas.

Protection and Restoration of Soil and Water Ecology to Achieve Harmonious Coexistence between Human and Nature

At present,the ecological environment crisis of global concern,such as climate warming and biodiversity loss,the fundamental reason is the change and destruction of the earth's soil and water ecology.Therefore,protecting and restoring the authenticity,diversity,cleanliness and integrity of soil and water ecology,we should coordinate and deal with the relationship between human beings and soil and water ecology,and realize the harmonious coexistence between human beings and nature from the three aspects of protecting natural soil and water ecology,protecting and restoring natural soil and water ecology,building and regenerating artificial soil and water ecology.

Comprehensive study on ecological restoration and land exploitation of mining subsidence in suburbs of Chinese mining cities

China has nearly a hundred mining cities derived from mining development.While mining development has brought about immense achievements in a city’s economic construction,it has also resulted in different levels of damage to the eco-environment of the mining city,leaving behind a lot of subsided wasteland and heavily confining the sustainable development and transformation there.How to restore and exploit the land and eco-environment disrupted by mining development in an effective way,therefore,has become a pressing challenge that Chinese mining cities are facing.In this paper,the planning and construction of Nanhu Eco-city in the suburb of Tangshan City is analyzed as an example.After characterizing the coal-mining subsided lands in Kailuan Tangshan Mine originated in different periods and under different geological mining conditions and evaluating their safety level,the authors try to demonstrate how eco-restoration and comprehensive land exploitation should be implemented by making the best use of available local resources to achieve "economy-society-environment" sustainability and coexistence in a mining city.

Ecosystem Development of Haizhou Bay Ecological Restoration Area from 2003 to 2013

Two Ecopath mass-balance models were implemented for evaluating the structure and function of Haizhou Bay Ecological Restoration Area ecosystem using 14 ecological indicators in two distinctive years(2003 and 2013). The results showed that the size of HZERA ecosystem became larger as total biomass was increased in last decade, especially in primary producer and zooplankton groups. Total system throughput increased from 7496.00 t km^(-2) yr^(-1) to 9547.54 t km^(-2) yr^(-1). The P/R(production/respiration) ratio decreased over the decade. Finn's cycling index and Finn's mean path length increased over the decade. No keystone species(KS) occurred during ten years; however, evidences of top-down control in 2003 and 2013 models were demonstrated by high KS value belonging to Lophius litulon group in food web. Drawing upon Odum's theory of ecosystem maturity, the structured, web-like ecosystem of 2013 model had developed into a highly mature system compared with that of 2003 model.

Application of Ecological Restoration and Sustainable Design Concept in Hong Kong Wetland Park

Wetland park has become an important content of urban landscape design in China, and it is urgent to explore the ways of ensuring scientifi c planning and design and successful implementation of the planning and design in the preparatory stage and the late habitat management and monitoring stage. Taking Hong Kong Wetland Park for example, this paper reviewed the successful design concepts and scientifi c management practices on the basis of sorting out its planning, construction, management and monitoring experience, to provide useful references for the planning, design and management of wetland park in other regions.

Study on the Ecological Restoration Techniques in Coal Mines——A Case Study of Mines in Huainan

Coal mining has brought serious damages to neighboring environment and ecosystem,and degradation of ecological environment has seriously influenced life of neighboring residents and sustainable development of coal industry.Destroyed ecological environment of mines in Huainan,Anhui Province was introduced in this study,ecological restoration principles,methods and procedures of mines were explored.The paper proposed that the harmonious development of economy,society and ecological environment must be considered in the ecological restoration.Combing with current situation of local mining areas,practical eco-restoration technical solutions were given by following ecological restoration principles to realize the sustainable development of mines.

PHENOMENON OF ESTABLISHING COENOSIUM IN DESERT AND THE ECOLOGICAL RESTORATION IN THE AREA AROUND THE OASIS

The area around the oasis, lying between the oasis and the natural desert and encirclesthe oasis is different from ecotone of the oasis and the desert, because it is not the trans-forming area betwen them, but it is ecological rift valley or ecological burst zone. The oasisbase will be shaked and the nature desert will be degenerative too. It is the crux of the envi-

Ecological Allocation of Plants in Ecological Restoration of the Danjiang River Basin

As the water source of central route of China's south-to-north water diversion project,the Danjiang River Basin shoulders a major historical mission.Therefore,it is imperative to perform ecological restoration for control of water and soil loss and improvement of the ecological environment.In this paper,based on the current status of research on ecological restoration at home and abroad,the layout principles of ecological restoration and functional traits of plants were analyzed.Afterwards,the principles and methods of plant selection in ecological restoration engineering were determined,and the ecological allocation plan of plants in ecological restoration for soil and water conservation in the Danjiang River Basin was proposed according to the specific conditions of the Danjiang River Basin.It provides reference for the ecological restoration and the sustainable development of the ecological environment in the Danjiang River Basin,and can also be used in other similar projects.

Seed movement of bare alkali-saline patches and their potential role in the ecological restoration in Songnen grassland, China

The dynamics of soil seed banks and seed movement was investigated in three bare alkali-saline patches in Songnen grassland, Northeast China, for exploring their potential role in the vegetation restoration of bare alkali-saline patches. The results showed that the seed banks and the seed movement in these patches were very similar to each other, and to some extent the seed movement was related to patch-side vegetation there. Seed movement across the soil surface of these bare alkali-saline patches was abundant and dominated by the seeds of pioneer species, such as Chloris virgata and Suaeda corniculata, which accounted for over 96% of these trapped seeds. In the contrast, soil seed banks of bare patches were extremely small, in different seasons, especially in May and June, even no any seed have been found, mainly due to lowest retaining capacity of surface soil to those abundant seed movement. Both soil seed banks and seed movement showed seasonal variation, and usually reached the maximum in October. Soil seed banks of bare alkali-saline patches, which were extremely small and difficult to recruit naturally, may inhibit speed of vegetation restoration. It is suggested that seed movement would be the potential seed source and play a potentially important role in the process of vegetation restoration of bare alkali-saline patches by enhancing the soft retaining capacity to seed movement.

Current Status and Control Measures of Ecological Restoration in Karst Rocky Desertification Area of Guizhou

[Objective] The aim was to analyze the current status and control measures of ecological restoration in Karst rocky desertification area of Guizhou.[Method] The current status and existing problems of ecological restoration in Karst rocky desertification area of Guizhou were studied firstly,and main control measures were put forward according to existing problems.[Result] At present,Karst rocky desertification area in Guizhou has suitable ecological environment,obvious control results and rich control experience,and there exist many problems like ambiguous concept of ecological restoration,biased control emphasis,single control measure and serious water shortage due to lagging engineering construction.Control measures mainly include combining natural restoration with artificial tending to speed up ecological restoration,reinforcing the restoration and rebuilding of development and construction project to prevent the deterioration of regional ecological environment,speeding up the construction of environmental friendly energy infrastructures to decrease the damage of vegetation by human activities,increasing industrial structure adjustment and greatly developing green industry and improving the investment in technological innovation to promote the rapid development of ecological restoration.[Conclusion] The study could provide scientific references for the ecological restoration in other Karst rocky desertification area in Southwest China.

Study on the Ecological Restoration Project of Dalian Lake

Choosing Dalian Lake as study area to implement ecological restoration project,the existing environmental problems in Dalian Lake were analyzed firstly,and then the project area in Dalian Lake was divided into wetland restoration and reconstruction area,forest wetland cultivation area and shallow wetland restoration and diversity conservation area,finally corresponding restoration measures were put forward according to various function areas,so as to improve the economic output of wetland and operability and sustainability of ecological restoration project,discuss harmonious development of lake ecological restoration and regional economy,and further provide references for wetland restoration project in Dianshan Lake and water environment control in Taihu Lake basin.

Experimental Research on the Application of Water Hyacinths to the Ecological Restoration of Water Bodies with Eutrophication

[Objective] The study aims to discuss the application of water hyacinths to the ecological restoration of water bodies with eutrophication through simulation experiments. [Method] In this study, water hyacinths were used to restore the simulated eutrophic water with green algae as the dominant algae species, and then the restoration effect of the simulated eutrophic water by water hyacinths was analyzed. [Result] In the simulation test without sediment, the peak chlorophyll concentration was 434.6 mg/m3 in the tank without water hyacinths, which decreased to 285 and 119 mg/m3 respectively in the tanks with 1 and 4 water hyacinths. In the experiment with sediment, compared with the control tank without water hyacinths, a 58% reduction in chlorophyll concentration could be observed in the tank with 4 water hyacinths planted (with a coverage of 51%). The results showed that water hyacinths could inhibit alga growth notably, but there was likely a density threshold (51% coverage), and no significant eco-restoration effect was observed in the simulated eutrophic water with too few water hyacinths planted. [Conclusion] The research could provide scientific references for the ecological restoration of eutrophic water bodies.

Effects of land use changes for ecological restoration on soil moisture on the Chinese Loess Plateau:a meta-analytical approach

Soil moisture is an important resource for plant growth on the arid and semi-arid Loess Plateau of China where the‘‘Grain for Green’’project was launched in 1999,but there has been no systematic evaluation of soil moisture from the effects of ecological restoration at a regional scale.We systematically assessed 63 published studies during 2000-2015,including 2050 observations at 68 sites on the Loess Plateau with the aim of determining soil moisture changes and the factors influencing those changes.We found that,after land use conversion,soil moisture decreased by 17%in the upper 100 cm soil layer and that tree plantations and shrub lands appeared to cause soil moisture depletion which became increasingly serious with soil depth.The decrease of soil moisture was significantly influenced by the planting species in all restoration types(tree plantations,shrub lands,and grasslands).We also found that tree plantations and grasslands converted from farmlands consumed more soil moisture than from wasteland(including bare land,abandoned land and wild grasslands).Artificial restoration led to significant soil moisture reduction,but natural restoration had little effect on soil moisture.Therefore,natural restoration should be an alternative restoration practice on the Loess Plateau.These results will provide helpful information for artificial afforestation and planning ecological restoration campaigns for policy makers on water-limited regions.

Effects of organic matter on the distribution of rare earth elements in red soil aggregates during ecological restoration

Rare earth elements(REEs)are widely applied in high-tech fields.However,their increasing presence in the food chain poses significant risks to human health.At present,little is known about the effects of organic matter on the distribution of ion-adsorbed REEs in soil aggregates during ecological restoration.Red soil derived from coarse-grained granite in Southern China is both prone to ecosystem degradation from soil erosion and rich in REEs.Understanding the distribution of REEs in soil aggregates undergoing ecological restoration is helpful to formulate effective measures for controlling the environmental migration of REEs.Four sites that had undergone different durations/degrees of ecological restoration were selected in the areas to analyze.REEs concentration of six different aggregates sizes(<0.25,0.25-0.5,0.5-1,1-2,2-5,and>5 mm)were analyzed and the enrichment coefficients were calculated in 4 sample sites of severe-degraded ecosystem in Changting County,Fujian Province,Southern China.The results showed that the total rare earth elements(TREEs)concentration in the aggregates increased from 213 mg kg^(-1) to 528 mg kg^(-1) with the extension of the ecological restoration time.At the initial stages of ecological restoration,there was no significant difference in the TREEs concentration among the six aggregates sizes.However,in the middle and late stages of restoration,the concentration of TREEs increased significantly with the decrease of aggregate size.The concentration of individual REEs showed three changing trends with sizes of aggregates during ecological restoration,respectively:1)no obvious regular change(S1),2)a V-shaped change trend(S2),and 3)increasing concentration with the decrease of aggregate size(S3 and S4).Ce and Eu showed a positive and negative anomaly in the soil aggregates,respectively.Moreover,the light rare earth elements(LREEs)were enriched,while the heavy rare earth elements(HREEs)were depleted during the initial stages,and the HREEs were enriched during the middle and late stages of restoration.The correlation coefficient between organic matter and REEs in aggregates was generally low;however,LREEs showed a stronger correlation with organic matter than that of HREEs during the initial stages of ecological restoration.The correlation between organic matter and HREEs gradually increased and even exceeded that of LREEs with on-going ecological restoration.The distribution of REEs concentration in degraded soil aggregates in Southern China showed obvious variability with the ecological restoration time.

Restoration and Rebuilding of Forestry Ecological System in Heilongjiang Province

The study on restoration and rebuilding of forestry ecological system was conducted on Xianfeng Forestry Farm (N45° 03′, E129° 45′), in Yilan county, Heilongjiang province. One thousand hectare sample land was established. The research summarized the comprehensive technique measures: to managed virgin forests perfectly, to promote forest reforestation by artificial treatment, to restore the secondary forest with patch pattern; and to restorc and foster felling land on artificial forest by means of natural pattern or close hillside to facilitate afforestation. The results showed that forest ecosystem function and quality were restored and rebuilt during ten years by utilization of these technique measures.