Spatiotemporal Evolution of Ecosystem Service Value in Caohai National Nature Reserve

Wetland ecosystems are important regulators of global climate change.Studying the spatiotemporal changes and driving mechanisms of their ecosystem service values(ESV)is beneficial for the sustainable development of wetlands.This paper uses the equivalent factor method,based on land use changes,to reveal the spatiotemporal evolution of the ecosystem service value in the Caohai National Nature Reserve(CNNR).The results show the following:①from 2000 to 2020,there was a significant decrease in the core zone s arable land area,with an increase in forest and water areas.Construction land mainly increased in the experimental area,and the grassland area showed a fluctuating change of first increasing and then decreasing;②in 2000,2010,and 2020,the ecosystem service value of the study area was 302 million,296 million,and 325 million yuan,respectively,showing a trend of fluctuating growth,with the value of wetland ecosystems playing a dominant role;③regulatory services are the main contributors to the ecosystem service value in the study area,with a contribution rate of 60%.Hydrological regulation is the ecosystem function with the highest value in wetland ecosystem services,contributing more than 35%to the ESV in all three periods;④in terms of spatial distribution,the core zone s ecosystem service value is dominant.Looking at the total ecosystem service value of the region,the core zone>the experimental area>the buffer zone.In terms of ESV per unit area,the core zone(89000 yuan/hm^(2))is significantly higher than the buffer zone(39100 yuan/hm^(2))and the experimental area(15800 yuan/hm^(2)).The study can provide a basis for research and spatial management of ecosystem services in wetland ecosystems and nature reserves.

Quantitative Evaluation on Wetland Ecosystem Service Function in Chao Lake

[Objective] The aim was to better reveal the type of ecosystem service function of wetlands in Chao Lake and provide references for protection and man- agement, restoration and rebuilding of local wetland ecosystem. [Method] The val- ues of ecosystem function was estimated by market value method, opportunity cost approach, replacement cost method, shadow engineering approach, travel cost method, hedonic pricing method and contingent value method. [Result] With wetland ecosystem service function value totals 4.968 billion yuan, the value of eco-environ- ment regulation and maintenance was the highest, followed by the value of cultural and social function. The value of material production was the least. The values of sub-functions can be concluded by comparison of service function va}ue and pro- portions, as follows： flood mitigation 〉water purification 〉water conservation 〉 tourism＆leisure〉material production〉scientific research and education〉water supply〉 biodiversity maintenance〉regulation on atmosphere constituents. [Conclusion] The re- search performed quantitative evaluations on ecosystem service function values of wetlands in Chao Lake and is of significance for specific development and protec- tion of local wetlands.

Nitrogen cycling of atmosphere-plant-soft system in the typical Calamagrostis angustifolia wetland in the Sanjiang Plain,Northeast China

The nitrogen （N） distribution and cycling of atmosphere-plant-soil system in the typical meadow Calamagrostis angustifolia wetland （TMCW） and marsh meadow Calamagrostis angustifolia wetland （MMCW） in the Sanjiang plain were studied by a compartment model. The results showed that the N wet deposition amount was 0.757 gN/（m^2·a）, and total inorganic N （TIN） was the main body （0.640 gN/（m^2·a））. The ammonia volatilization amounts of TMCW and MMCW soils in growing season were 0.635 and 0.687 gN/m^2, and the denitrification gaseous lost amounts were 0.617 and 0.405 gN/m^2, respectively. In plant subsystem, the N was mainly stored in root and litter. Soil organic N was the main N storage of the two plant-soil systems and the proportions of it were 93.98% and 92.16%, respectively. The calculation results of N turnovers among compartments of TMCW and MMCW showed that the uptake amounts of root were 23.02 and 28.18 gN/（m^2·a） and the values of aboveground were 11.31 and 6.08 gN/（m^2·a）, the re-translocation amounts from aboveground to root were 5.96 and 2.70 gN/（m^2·a）, the translocation amounts from aboveground living body to litter were 5.35 and 3.38 gN/（m^2·a）, the translocation amounts from litter to soil were larger than 1.55 and 3.01 gN/（m^2·a）, the translocation amounts from root to soil were 14.90 and 13.17 gN/（m^2·a）, and the soil （0-15 cm） N net mineralization amounts were 1.94 and 0.55 gN/（m^2·a）, respectively. The study of N balance indicated that the two plant-soil systems might be situated in the status of lacking N, and the status might induce the degradation of C. angustifolia wetland.

Growth pattern of reed in Caogang Lake,Huanghuaihai Plain,China

The researches about reed growth were mainly concentrated on seasonal dynamics, investigation of reed resource, and comparison of different ecotypes of reed. By means of fractal geometric theory of non linear science, the fractal character of growth pattern of reed, for the purpose of quantitatively exploring the mechanism of reed growth was studied. The way to calculate fractal dimension of reed growth is box dimension (BD) and information dimension (ID). The results showed that the difference between two samplings in May and those among three samplings in June and later were not remarkable for both BD or ID. It was noted that the difference between samplings in and after May is significant. It was demonstrated that the fractal dimension of size distribution of reed ranged from 0 6235 to 0 8761 The distribution pattern could be statistically divided as two significant periods: the size of reed is quite well distributed at the beginning of reed growth (fractal dimension>0 8), but is irregular in the middle and later growth season (fractal dimension<0 7). These results are benefit to reach the goal of rational use of reed resources and to protect the biodiversity in wetland ecosystem.

CLOBAL CHARM OF THE CHANGJIANG RIVER DELTA

Based on the theory of geo-economy,under the new situation of global economy,information network and China’s entry into WTO,also with the holding of APEC (in 2001) and the International Exposition in the near future,the Changjiang (Yangtze) River Delta is striding toward the spectacular international multi-polar situation and becomes one of core regions with high-speed development. Facing the ocean and world all along,leading the progressive tides of the age and scintillating the splendor of the nation,she does advance with time. Through a long period of irrigation projects construction and intensive operation of lands in previous agricultural society,the artificial wetland ecosystem with a positive cycle had ever been formed in this region. At present,environmental pollution and urban expansion resulted from post-industrialization are being rectified. The delta will be the paradigm of industrial and agricultural modernization along the sustainable development road. With the rapid development of urbanization,she has been one of the regions with the highest density population and high urbanization level. Taking the Changjiang River estuary and the Hangzhou Bay as two parts,she is continuously strengthening and adjusting her interior structure,expanding mothball space and constructing the oriental modern "logistics center" to link the whole world. The butterfly-style urban system of the Changjiang River Delta is flying,probably engendering earthshaking "butterfly effect".

Quantifying land degradation in the Zoige Basin,NE Tibetan Plateau using satellite remote sensing data

Considerable efforts have been dedicated to desertification research in the arid and semi-arid drylands of central Asia. However,there are few quantitative studies in conjunction with proper qualitative evaluation concerning land degradation and aeolian activity in the alpine realm. In this study,spectral information from two Landsat-5 TM scenes(04.08.1994 and 28.07.2009,respectively) was combined with reference information obtained in the field to run supervised classifications of eight landscape types for both time steps. Subsequently,the temporal and spatial patterns of the alpine wetlands/grasslands evolutions in the Zoige Basin were quantified and assessed based on these two classification maps. The most conspicuous change is the sharp increase of ~627 km^2 degraded meadow. Concerning other land-covers,shallow wetland increases ~107 km^2 and aeolian sediments(mobile dunes and sand sheets) have an increase of ~30 km^2. Considering the deterioration,an obvious decrease of ~440 km^2 degraded wetland can be observed. Likewise,decrease of deep wetland(~78 km^2),humid meadow(~80 km^2) and undisturbed meadow(~88 km^2) were determined. These entire evolution matrixes undoubtedly hint a deteriorating tendency of the Zoige Basin ecosystem,which is characterized by significantly declined proportion of intact wetlands,meadow,rangeland and a considerable increase ofdegraded meadow and larger areas of mobile dunes. In particular,not only temporal alteration of the landcover categories,the spatial and topographical characteristics of the land degradation also deserves more attention. In the alpine rangelands,the higher terraces of the river channels along with their slopes are more liable to the degradation and desertification. This tendency has significantly impeded the nomadic and agriculture activities. The set of anthropozoogenic factors encompassing enclosures,overgrazing and trampling,rodent damaging and exceedingly ditching in the wetlands are assumed to be the main controlling mechanisms for the landscape degradation. A suite of strict protection policies is urgent and indispensable for self-regulation and restoration of the alpine meadow ecosystem. Controlling the size of livestock,less ditching in the rangeland,and the launching of a more strict nature reserve management by adjacent Ruoergai,Maqu and Hongyuan Counties would be practical and efficacious in achieving these objectives.

Wetland Economic Valuation Approaches and Prospects in China

Ecosystem services valuation seeks to increase the social relevance of ecosystem characteristics, the underlying biological mechanisms that support services, by making the contribution of ecosystems to human well-being explicit. Economic valuation can help management by clarifying the full range of benefits and costs of proposed management actions. In the past two decades, economic valuation of wetland ecosystem services has become one of the most significant scientific priorities for wetland protection. In this paper, we provide an overview of ecosystem services, and summarize the main interdisciplinary approaches to measure and value wetland ecosystem services. We identified four main methodological gaps preventing progress on wetland valuation of ecosystem services in China, which are: 1) confusion on terminology like intermediate and final ecosystem services, 2) lack of ecological production functions to link ecosystem characteristics to final ecosystem services, 3) static valuation making it difficult to evaluate the trade-offs and synergies among ecosystem services, and 4) lack of clear guidance on relating ecological compensation programs to conservation targets. Overcoming these gaps is important to inform wetland compensation mechanisms and conservation policies. We propose future research on wetland ecosystem services in China should be focused on: 1) defining final ecosystem services based on beneficiary preferences and underlying biophysical mechanisms, 2) establishing wetland monitoring programs at specific sites to collect data on final ecosystem service indicators and ecosystem characteristic metrics to create ecological production functions for economic valuation and rescaling techniques, and 3) incorporating wetland ecosystem service values into decision-making processes to inform wetland management.

Cutting of Phragmites australis as a lake restoration technique： Productivity calculation and nutrient removal in Wuliangsuhai Lake, northern China

Reed is one of the most frequent and dominant species in wetlands all over the world, with common reed （Phragmites australis （Cav.） Trin. ex Steud.） as the most widely distributed species. In many wetlands, P. australis plays a highly ambivalent role. On the one hand, in many wetlands it purifies wastewater, provides habitat for numerous species, and is a potentially valuable raw material, while on the other hand it is an invasive species which expands aggressively, prevents fishing, blocks ditches and waterways, and builds monospecies stands. This paper uses the eutrophic reed-swamp of Wuliangsuhai Lake in Inner Mongolia, northern China, as a case to present the multiple benefits of regular reed cutting. The reed area and aboveground biomass production are calculated based on field data. Combined with data about water and reed nutrient content, the impact of reed cutting on the lake nutrient budget （N and P） is investigated. Currently, at this lake around 100,000 tons of reed are harvested in winter annually, removing 16% and 8% of the total nitrogen and phosphorus influx, respectively. Harvesting all available winter reed could increase the nutrient removal rates to 48% and 24%, respectively. We also consider the effects of summer harvesting, in which reed biomass removal could overcompensate for the nutrient influx but could potentially reduce reed regrowth.

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.

Surface Water and Groundwater Interactions in Wetlands

Wetland ecosystems are critical habitats for various types of wild lives and are important components of global ecosystem. However, with climate change and human activities, wetlands are facing with degradation. Surface water and groundwater(SW-GW) interactions play an essential role in matter and energy cycling in wetlands, and therefore affect the evolution and health of wetlands. But the role of groundwater in wetland ecosystems has been neglected or simplified. In this paper, we reviewed how surface water interacts with groundwater, and made a systematic summarization of the role of SW-GW interactions(such as maintaining water balance and biological diversity and removing pollution) in wetland ecological functions. We also reviewed the methods to investigate, simulate and quantify SW-GW interactions and related reactions. Finally, we illustrated how climate change and human activities affect SW-GW interactions and therefore affect wetland functions. We highlight the importance of groundwater in wetlands and the urgency to intensify the research in integrated multidisciplinary monitoring and simulation methods, dominant variables and thresholds and integrated water resources management of SW-GW interactions, and further aim to stimulate better protection and restoration of wetlands all over the world.

Production and emission of phosphine gas from wetland ecosystems

Phosphine is a part of an atmospheric link of phosphorus cycle on earth, which could be an important pathway for phosphorus transport in environment. Wetland ecosystems are important locations for global biogeochemical phosphorus cycle. In this study, production and emission fluxes of free phosphine from four wetlands types in southern China were observed in different seasons. The results showed that the concentration of phosphine liberated from wetlands was at pg/m^3·ng/m^3 level. The emission concentrations of different wetlands followed the sequence： paddy field （51.83 ± 3.06） ng/m^3 〉/marsh （46.54 ± 20.55） ng/m^3 〉 lake （37.05 ± 22.74） ng/m^3 〉〉 coastal wetland （1.71 ± 0.73） ng/m^3, the positive phosphine emission flux occurred in rice paddy field （6.67 ± 5.18） ng/（m^2.hr） and marsh （6.23 ± 26.9） ng/（m^2.hr）, while a negative phosphine flux of （-13.11 ± 35.04） ng/（m^2.hr） was observed on the water-air interface of Lake Taihu, suggesting that paddy field and marsh may be important sources for phosphine gas in atmosphere, while lake may be a sink of atmospheric phosphine gas during the sampling period. Atmospheric phosphine levels and emission flux from Yancheng marsh and rice paddy field varied in different seasons and vegetational zones. Both diffusion resistance in aqueous phase and temperature were dominating factors for the production and transportation of phosphine to atmosphere.

EMERGY analysis for sustainability evaluation of the Baiyangdian wetland ecosystem in China

t This study presents a quantitative and ecological benefit evaluation of the Baiyangdian wetland in China between the years 2000 and 2006.Methods of EMERGY analysis were applied to illustrate the wetland ecosystem,to evaluate the economic and environmental inputs and consequent yields,and to assess the sustainability of the Baiyangdian wetland.The indicators for the integrated ecological and economic system,such as EMERGY yield ratio(EYR)(7.51),EMERGY investment ratio(EIR)(4.52),environmental loading ratio(ELR)(2.92),EMERGY exchange ratio(0.41),and EMERGY sustainable indicator(ESI)(2.57)were calculated,compared,analyzed,and discussed.The non-renewable investment in Baiyangdian was greater than renewable investment,leading to the unsustainable development of the system.High EYR indicated that the Baiyangdian integrated system had created huge profits for its people,while ELR and ESI revealed that human behavior has been a heavy burden on the environment,and countermeasures should be taken by the Chinese government to relieve and resolve these problems.Potential management methods were also proposed in this paper.

Balanced nitrogen economy as a flexible strategy on yield stabilizing and quality of aquatic food crops in wetland ecosystem

In wetland ecosystem, nitrogen along with other elements and its management is most imperative for the production of so many aquatic food, non-food and beneficial medicinal plants and for the improvement of soil and water characteristics. With great significant importance of INM (integrated nutrient management) as sources, emphasizing on management on nitrogen as a key element and its divergence, a case study was undertaken on such aquatic food crops (starch and protein-rich, most popular and remunerative) in the farmers' field of low-lying 'Tal' situation of New Alluvial Zone of Indian subtropics. The study was designed in factorial randomized block design, where, three important aquatic food crops (water chestnut (Trapa bispinosa Roxb.), makhana (Euryale ferox Salisb.) and water lily (Nymphaea spp.) as major factor and eleven combinations of organic and inorganic sources of nutrients as sub-factor was considered in the experiment. It revealed from the results that the production of fresh kernels or nuts of water chestnut (8.571 ha-1), matured nut yield of makhana (3.06 t ha-1) and flower stalks of water-lily as vegetables (6.38 t ha-1) including its nutritional quality (starch, protein, sugar and minerals) was remarkably influenced with the application of both organic (neem oilcake @ 0.2 t ha-1) and inorganic sources (NPK @ 30:20:20 kg ha-1 along with spraying of NPK @ 0.5% each over crop canopy at 20 days interval after transplanting) than the other INM combinations applied to the crops. Among the crops, highest WCYE (water chestnut yield equivalence) exhibited in makhana due to its high price of popped-form in the country, which is being exported to other countries at now. Sole application of both (organic and inorganic sources) with lower range did not produce any significant outcome from the study and exhibited lower value for all the crops. Besides production of food crops, INM also greatly influenced the soil and water characterization and it was favourably reflected in this study. The physico-chemical characteristics of soil (textural class, pH, organic carbon, organic matter, ammoniacal nitrogen, nitrate nitrogen, available nitrogen, phosphorus and potassium) are most important and contributed a significant improvement due to cultivation of these aquatic crops. Analysis of such wet bodies represented the water characteristics (pH, BOD, COD, CO3 =, HCO3-, NO3- N, SO4-S and Cl-) were most responsive, adaptable and quite favourable for the cultivation of these crops in this vast waste unused wetlands for the mankind without any environmental degradation.

A critical review of policies and legislation protecting Tanzanian wetlands

Introduction:The benefit of wetlands for reducing poverty depends on the effectiveness of governance systems that influence peoples’behaviour in the wise use of wetlands.Objectives:This article critically analyses the current poverty reduction strategies,agrarian policies and economic investments governing wetland usage,especially in Tanzania,with regard to their impact on sustainable Ramsar wetlands management.Methodology:It analyses the management structure,domestic policies and legal framework relating to the protection of wetlands in Tanzania in accordance to the wise use concept of the Ramsar Convention.Outcomes:Tanzanian legal provisions for wetland protection are uncoordinated and too limited in their coverage and scope to sufficiently address the destruction of wetland ecosystems.There is no comprehensive national legal framework to guide sustainable management of Ramsar wetlands in Tanzania as laid out by the Ramsar Convention,which the country ratified in the year 2000.Conclusion:Without a sound legislative and policy-making framework,Tanzanian wetlands and their diverse ecosystem services will continue to degenerate with current strategies of increasing agribusiness and other developmental projects or economic investments.This paper provides critical baseline information to inform decision makers to develop appropriate policy and laws,which promote the wise use of wetlands in Tanzania.