Soil Cellulase Activity and Fungal Community Responses to Wetland Degradation in the Zoige Plateau,China

Four soil types(peat, marsh, meadow, and sandy) in the Zoige Plateau of China are associated with the severity of wetland degradation. The effects of wetland degradation on the structure and abundance of fungal communities and cellulase activity were assessed in these 4 soil types at 3 depths using DGGE(Denatured Gradient Gel Electrophoresis), q PCR(Quantitative Real-time PCR),and 3,5-dinitrosalicylic acid assays. Cellulase activity and abundance of the fungal community declined in parallel to the level of wetland degradation(from least to most disturbed). DGGE analysis indicated a major shift in composition of fungal communities among the4 soil types consistent with the level of degradation.Water content(WC), organic carbon(OC), total nitrogen(TN), total phosphorus(TP), available nitrogen(AN), and available phosphorus(AP) were strongly correlated with cellulase activity and the structure and abundance of the fungal community.The results indicate that soil physicochemical properties(WC, OC, TN, TP, AN, and AP), cellulase activity, and diversity and abundance of fungal communities are sensitive indicators of the relative level of wetland degradation. WC was the major factorinvolved in Zoige wetland degradation and lower WC levels contributed to declines in the abundance and diversity of the fungal community and reduction in cellulase activity.     

A METHOD TO ESTIMATE PALEOTEMPERATURE FROM ENVIRONMENTAL PROXIES IN LAKE SEDIMENTS——A STUDY ON ZOIGE BASIN IN EASTERN TIBETAN PLATEAU, CHINA

Seeking for an effective method to probe further the relation among Tibetan Plateau, climatic events, and natural environmental changes in the Zoige Basin, we proposed a physical model for the reconstruction of climate and environment and a preliminary application was conducted on the 45 m (about 200 ka BP), upper part of Core RM (310 m long) drilled in the Zoige Basin (33°57’N, 102°21’E), on the eastern Tibetan Plateau. The results showed that: a) in the Zoige region, the maximum temperature in the period equivalent to Stage 7 in the deep-sea stable oxygen record was 2.7°C higher than that at present; b) Stage 6 temperature was 4.3°C lower than that at present; c) Stage 5 peak temperature was 5.2°C higher that that at present; d) Stage 4 average temperature should have been 2–3°C lower than that at present; and e) Stage 3 temperature differences within the period were more than 4°C. It was found that during Stage 6 (140–160 ka BP) the environment in the Zoige Basin was extraordinary, representing a transition period from warm-dry and cold-wet to warm-wet and cold-dry environmental conditions due to the uplift that occurred on the Tibetan Plateau at this period. Project 49803001 supported by NSFC and also funded by National and CAS Tibet Research Project (G1998040800).     

若尔盖高原湿地景观与环境要素的DCCA多元相关分析

以9个指标反映若尔盖高原湿地生境的环境特征,在ArcGIS 9.2平台下进行随机样方布设,采用DCCA排序方法定量分析湿地景观与环境要素之间的关系。结果表明：(1)排序前2轴累计解释了湿地景观与环境要素关系的79.4％,表明其具有有效的目标研究显示度;(2)沿地形指数所近似表达的水分状况梯度,研究区各景观类型具有明显的...     

A water movement study in Lianzhou Bay,Guangxi Province,China

This study investigates the physical conditions (water depth, current speed, salinity, temperature) in Lianzhou Bay, a shallow coastal bay in southern China, during two expeditions in the dry and wet seasons of 2011. Based on these expedition data, basic hydrodynamic parameters like Brunt-Väisälä Frequency, Richardson Number, Rossby radius, and Resonance Period are calculated. The results show that Lianzhou Bay is characterized by comparatively small quantity of freshwater input and weak stratification. Strong tides, which are spatially uniform within the bay, cause turbulent mixing. Residence time of the water is shorter in winter due to a stronger coastal current in that season. Consideration of the water movement may help to reduce the harmful ecological impact of aquaculture waste water discharge.     

Tourist Behaviors in Wetland Park： A Preliminary Study in Xixi National Wetland Park, Hangzhou, China

Public education as well as tourism and leisure are the two important functions of national wetland park, and tourist behaviors act as the guiding factor in the national wetland park construction and management. As the first national wetland park in China, Xixi National Wetland Park, located in Hangzhou City, Zhejiang Province, will give constructive instructions to the construction and management of other wetland parks and ecotourism resorts. This paper analyzed the tourist behaviors in Xixi National Wetland Park. By the observation, in-depth interview and questionnaire, the results show that tourists in wetland parks are different from those in the other common destinations, and they are also different from those strict eco-tourists. In fact, the tourists in wetland park have unique characteristics, such as the intense perception to the functions of wetland ecosystem and the environment impact behaviors. Those tourists are preferred to natural landscapes in their motivations and expectations. Wetland landscapes are the main image to those tourists in the Xixi National Wetland Park. Tourist expectation, experience and satisfaction are all critical factors for the success of the planning and management in national wetland parks. Based on the results, some measures for the sustainable development of wetland parks, including to optimize wetland theme landscape and tourism products, to improve tourist facilities and services, to enhance quality of visitor experiences, and to implement total quality management based on tourist characteristics, are given to national wetland park ecotourism.     

Responses of soil inhabiting nitrogen-cycling microbial communities to wetland degradation on the Zoige Plateau,China

The wetlands on the Zoige Plateau have experienced serious degradation, with most of the original marsh being converted to marsh meadow or meadow. Based on the 3 wetland degradation stages, we determined the effects of wetland degradation on the structure and relative abundance of nitrogen-cycling (nitrogen-fixing, ammonia-oxidizing, and denitrifying) microbial communities in 3 soil types (intact wetland: marsh soil; early degrading wetland: marsh meadow soil; and degraded wetland: meadow soil) using 454-pyrosequencing. The structure and relative abundance of nitrogen-cycling microbial communities differed in the 3 soil types. Proteobacteria was the predominant phylum in most soil samples but the most abundant soil nitrogen-fixing and denitrifying microbial bacteria differed at the class, order, family, and genus levels among the 3 soil types. At the genus level, the majority of nitrogen-fixing bacterium sequences related to Bradyrhizobium were from marsh and marsh meadow soils; whereas those related to Geobacter originated from meadow soil. The majority of ammonia-oxidizing bacterium sequences related to Nitrosospira were from marsh (except for the 40-60 cm layer), marsh meadow and meadow soils; whereas those related to Candidatus Solibacter originated from 40-60 cm layer of marsh soil. The majority of denitrifying bacterium sequences related to Candidatus Solibacter and Anaeromyxobacter were from marsh and meadow soils; whereas those related to Herbaspirillum originated from meadow soil. The distribution of operational taxonomic units (OTUs) and species were correlated with soil type based upon Venn and Principal Coordinates Analysis (PCoA). Changes in soil type, caused by different water regimes were the most important factors influencing compositional changes in the nitrogen-fixing, ammonia-oxidizing, and denitrifying microbial communities.     

Effects of terracing and agroforestry on soil and water loss in hilly areas of the Sichuan Basin,China

Soil erosion in hilly areas of the Sichuan Basin is a serious concern over sustainable crop production and sound ecosystem. A 3-year experiment was conducted using the method of runoff plots to examine the effects of terracing and agroforestry in farmland systems on soil and water conservation of slope fields in the hilly areas in Jianyang County, Sichuan Province, Southwestern China. A power function （Y = aX^b） can statistically describe the relationship between water runoff （Y） and rainfall （X）. The regression equation for the treatment of sloping terraces with crops （Plot 2） is remarkably different from that for the treatment of sloping terraces with grasses and trees （Plot 1） and the conventional up- and down-slope crop system （Plot 3） regarding equation coefficients, while regression equations are similar between Plot 1 and Plot 3. Water runoff amount and runoff coefficient of slope fields increased by 21.5-41.0 % and 27.5 - 69.7 % respectively, compared to those of sloping terraces, suggesting that terracing notably reduced the water runoff in the field. In the case of sloping terraces, lower amount of water runoff was observed on sloping terraces with crops than on sloping terraces with grasses and trees. Sediment yields on the slope fields in the normal year of rainfall distribution were notably higher （34.41 - 331.67 % and 37.06-403.44 % for Plot 1 and Plot 2, respectively） than those on sloping terraces, implying that terracing also plays a significant role in the reduction in soil erosion. It is suggested that terracing with crops is significantly effective for soil and water conservation in cultivated farmland, while the conventional practice of up- and down- slope cultivation creates high rates of water runoff and soil sediment transport. Terracing with grasses and fruit trees shows a less reduction in water runoff than terracing with crops, which was observed in the 3-year experiments.     

Effects of Climatic Change on Evapotranspiration in Zhalong Wetland, Northeast China

1 Introduction As a result of persistent increase in carbon dioxide in the atmosphere since the 1950s, global and regional climate features, such as temperature and precipitation, have ob- viously changed (Yu et al., 2002). The General Circulation Models (GCMs) provide potential climate scenarios by studying the effects of carbon dioxide on the temperature. Tickell (1993) predicted that the mean temperature will increase by 1℃ till the year 2050 and by 3℃ at the end of the 22th century. S…     

Niches of dominant fish in the waters surrounding the Taishan Islands,China

An index of relative importance (IRI) was employed to screen for dominant fish in the waters surrounding the Taishan Islands, China, using data from four seasonal trawl surveys undertaken between 2012 and 2013. Niche breadth and niche overlap were measured using the Feinsinger and Morisita-Horn indices, respectively, and the characteristics and seasonal variations in the niches of dominant fish were assessed via non-metric multidimensional scaling (NMDS) and cluster analysis. A total of 80 fish species, including 16 dominant species, were recorded. Only Amblychaeturichthys hexanema was dominant in all seasons. According to niche breadth values and NMDS, the 16 dominant species were grouped into the following three types: (1) wide niche breadth species, including Cynoglossus macrolepidotus, A. hexanema, and Trypauchen vagina, among others; (2) medium niche breadth species, including Setipinna taty and Johnius belangerii; and (3) narrow niche breadth species, including Atrobucca nibe and Coilia mystus. Most species with a wider niche breadth were demersal fish with a lower swimming capability and even distribution. The niche breadth of migrating fish was narrower than that of settled fish. At a given spatial scale, fish with stronger swimming capabilities had a narrower niche breadth. Niche overlap, which is associated with niche specialization, ranged from 0.000 to 0.886 and had an annual mean value of 0.314. In summer and autumn, niche overlap was relatively high within species of the Sciaenidae family and within species of the Gobiidae in autumn. Differences in thermophily, feeding habits, food organism abundance/distribution and predator-prey relationships affected the niche overlap of fish in this area. Cluster analysis revealed that species with the narrowest niche breadth and lowest niche overlap values usually displayed lower aggregation and greater distribution differences compared with other species.     

A study on the water area changes in the North China plain by using remote sensing technology

Study results on changes of rivers, lakes and coastlines have great significance for water resource exploitation, land use planning, industry, and agriculture. Recognition of traces of changed water areas can be done more quickly and correctly by processing multitime and multi-type remote sensing data and image matching and enhancement with computer and optical equipments than by using conventional methods. Features of water area changes in ancient times can be recoverd by comparing Landsat data and airphotos with historical records. Remote sensing technique is very efficient for monitoring short-term quantitative changes of water areas. Systematic analysis of the remote sensing data of this region shows that river changes have become less frequent, that the area of lakes has decreased year by year, and that the coast line at the river mouth has continually moved seaward. Huanghe river activity caused changes of water areas here in ancient times. But human activities have been playing an increasingly important role in modern times.     

Assessing the effects of oyster/kelp weight ratio on water column properties: an experimental IMTA study at Sanggou Bay,China

Journal of Oceanology and Limnology - Integrated Multi-Trophic Aquaculture (IMTA) is an effective method for sustainable aquaculture as species from different trophic levels could reduce negative...     

Value Assessment of Wetland Ecosystem Services in the Da Hinggan Mountains,China

This study examined regional differences in ecosystem services for the Da Hinggan Mountains(DHM),China.A correction index was constructed based on ten-year aver...     

高邮凹陷断层控油气作用的多样性

在探讨高邮凹陷断层发育时期和分布特点的基础上,结合油气分布特点,分析了断层在油气成藏中的作用类型,并探讨了其作用机理。依据断层在油气生成、运移、聚集和分布环节中的作用,把断层分为控源断层、供烃断层、改向断层、成圈断层和调整破坏断层。控源断层控制有效烃源岩展布和生烃时期的早晚,高邮凹陷控源断层下降盘为有效烃源岩分布区,而且西部地区早于东部地区生烃;供烃断层控制油气主运移通道的走势,其陡断面和凸断面为高邮凹陷断裂带油气的主运移通道;改向断层影响油气的富集层位和油气富集区的位置,其对高邮凹陷油气分布的影响存在"分散"和"富集"两种效应;成圈断层控制圈闭的类型及分布;调整破坏断层导致圈闭充满程度和原油物性的改变,高邮凹陷调整破坏断层为盐城期和三垛期活动断层。高邮凹陷断层的多期性和多样性导致断层体系中各断层封闭性在时空上的差异性和多变性,从而形成对油气控制的多面性和复杂性。     

Evaluating mountain water scarcity on the county scale: a case study of Dongchuan District,Kunming, China

Mountain water, which contributes 50% to 90% to the lower reaches of the watershed, has a considerably low utility efficiency. The water accessibility could be a quantitative measure of water scarcity in the mountains. It can be used effectively for emergency water shortage planning and water resource management. In the present study, Dongchuan District, a typical county in the Hengduan Mountains in Yunnan province of Southwest China, was selected as the study area, and the minimal cumulative resistance(MCR) model was used to simulate the least-cost path(LCP) from 1255 point features of natural villages, as well as 12,368 dryfield centroids, to their respective surrounding river systems, which serve as a source for emergency drinking water and irrigation during droughts. The average length of the LCP for each administrative village was calculated to represent the accessibility to water sources for agricultural production and daily life in these mountain villages. The distribution of population and dryfields, as well as other geographic elements, were analyzed to classify the degree of water scarcity in these villages. The results indicate that the area facing the highest risk of water shortage for agricultural irrigation is located in northern Dongchuan, in particular along the two sides of the Xiaojiang Valley, and that the area with the highest risk of water shortage for daily life needs is located along the Xiaojiang Valley.     

Seasonal and Spatial Variability of Water Quality and Nutrient Removal Efficiency of Restored Wetland: A Case Study in Fujin National Wetland Park,China

To investigate the spatio-temporal and compositional variation of selected water quality parameters and understand the purifying effects of wetland in Fujin National Wetland Park(FNWP), China, the trophic level index(TLI), paired samples t-test and correlation analysis were used for the statistical analysis of a set of 10 water quality parameters. The analyses were based on water samples collected from 22 stations in FNWP between 2014 and 2016. Results initially reveal that total nitrogen(TN) concentrations are above class V levels(2 mg/L), total phosphorus(TP) concentrations are below class Ⅲ levels(0.2 mg/L), and that all other parameters fall within standard ranges. Highest values for TN, pH, and Chlorophyll-a were recorded in 2016, while the levels of chemical oxygen demand(COD_(Mn)) and biochemical oxygen demand(BOD5) were lowest during this year. Similarly, TN values were highest between 2014 and 2016 while dissolved oxygen(DO) concentrations were lowest in the summer and TP concentrations were highest in the autumn. Significant variations were also found in Secchi depth(SD), TN, CODMn(P 0.01), TP, and DO levels(P 0.05) between the inlet and outlet of the park. High-to-low levels of TN, TP, and TDS were found in cattails, reeds, and open water(the opposite trend was seen in SD levels). Tested wetland water had a light eutrophication status in most cases and TN and TP removal rates were between 7.54%–84.36% and 37.50%–70.83%, respectively. Data also show no significant annual changes in water quality within this wetland, although obvious affects from surrounding agricultural drainage were nevertheless recorded. Results reveal a high major nutrient removal efficiency(N and P). The upper limits of these phenomena should be addressed in future research alongside a more efficient and scientific agricultural layout for the regions in and around the FNWP.     

Stable isotopes of water as a tracer for revealing spatial and temporal characteristics of groundwater recharge surrounding Qinghai Lake,China

Studying spatial and temporal characteristics of regional groundwater recharge will guide the scientific management and sustainable development of regional water resources.This study investigated stable isotopes(δ¹⁸O and δ² H) of precipitation,groundwater,river water and lake water during 2019-2020 in Qinghai Lake Basin to reveal the spatial and temporal characteristics of groundwater recharge.The local meteoric water line was simulated using ordinary least squares regressi...     

A STUDY ON THE FLORISTIC PLANT GEOGRAPHY OF XISHA ISLANDS, SOUTH CHINA

邢福武，李泽贤，叶华谷，陈炳辉，吴德邻ＡＳＴＵＤＹＯＮＴＨＥＦＬＯＲＩＳＴＩＣＰＬＡＮＴＧＥＯＧＲＡＰＨＹＯＦＸＩＳＨＡＩＳＬＡＮＤＳ，ＳＯＵＴＨＣＨＩＮＡ￥ＸｉｎｇＦｕｗｕ；ＬｉＺｅｘｉａｎ；ＹｅＨｕａｇｕ；ＣｈｅｎＢｉｎｇｈｕｉ；ＷｕＤｅｌｉｎ（...     

Driving forces and their effects on water conservation services in forest ecosystems in China

Identifying the driving forces that cause changes in forest ecosystem services related to water conservation is essential for the design of interventions that could enhance positive impacts as well as minimizing negative impacts. In this study, we propose an assessment concept framework model for indirect-direct-ecosystem service (IN-DI-ESS) driving forces within this context and method for index construction that considers the selection of a robust and parsimonious variable set. Factor analysis was integrated into two-stage data envelopment analysis (TS-DEA) to determine the driving forces and their effects on water conservation services in forest ecosystems at the provincial scale in China. The results showed the following. 1) Ten indicators with factor scores more than 0.8 were selected as the minimum data set. Four indicators comprising population density, per capita gross domestic product, irrigation efficiency, and per capita food consumption were the indirect driving factors, and six indicators comprising precipitation, farmland into forestry or pasture, forest cover, habitat area, water footprint, and wood extraction were the direct driving forces. 2) Spearman’s rank correlation test was performed to compare the overall effectiveness in two periods: stage 1 and stage 2. The calculated coefficients were 0.245, 0.136, and 0.579, respectively, whereas the tabulated value was 0.562. This indicates that the driving forces obviously differed in terms of their contribution to the overall effectiveness and they caused changes in water conservation services in different stages. In terms of the variations in different driving force effects in the years 2000 and 2010, the overall, stage 1, and stage 2 variances were 0.020, 0.065, and 0.079 in 2000, respectively, and 0.018, 0.063, and 0.071 in 2010. This also indicates that heterogeneous driving force effects were obvious in the process during the same period. Identifying the driving forces that affect service changes and evaluating their efficiency have significant policy implications for the management of forest ecosystem services. Advanced effectiveness measures for weak regions could be improved in an appropriate manner. In this study, we showed that factor analysis coupled with TS-DEA based on the IN-DI-ESS framework can increase the parsimony of driving force indicators, as well as interpreting the interactions among indirect and direct driving forces with forest ecosystem water conservation services, and reducing the uncertainty related to the internal consistency during data selection.     

Landscape pattern evolution processes of alpine wetlands and their driving factors in the Zoige Plateau of China

Zoige Plateau wetlands are located in the northeastern corner of the Qinghai-Tibet Plateau.The landscape pattern evolution processes in the Zoige Plateau and their driving factors were identified by analyzing the dynamic changes in landscape modification and conversion and their dynamic rates of alpine wetlands over the past four decades.The results showed that the landscape conversion between wetlands and non-wetlands mainly occurred during the period from 1966 to 1986.The marsh wetland area converted from lake and river wetlands was larger because of swamping compared to other wetland landscapes.Meanwhile,the larger area of marsh wetlands was also converted to lake wetlands more than other types of wetlands.The modification processes mainly occurred among natural wetland landscapes in the first three periods.Obvious conversions were observed between wetland and nonwetland landscapes(i.e.,forestland,grassland,and other landscapes) in the Zoige Plateau.These natural wetland landscapes such as river,lake and marsh wetlands showed a net loss over the past four decades,whereas artificial wetland landscapes(i.e.,paddy field and reservoir and pond wetlands) showed a net decrease.The annual dynamic rate of the whole wetland landscape was 0.72%,in which the annual dynamic rate of river wetlands was the highest,followed by lake wetlands,while marsh wetlands had the lowest dynamic rate.The integrated landscape dynamic rate showed a decreasing trend in the first three periods.The changes in wetland landscape patterns were comprehensively controlled by natural factors and human activities,especially human activities play an important role in changing wetland landscape patterns.     

Evaluation of tidal stream energy and its impacts on surrounding dynamics in the Eastern Region of Pingtan Island,China

Using an improved FVCOM numerical model, combined with the momentum-sinking scheme based on the structural characteristics of specific turbines, this study analyzed the temporal and spatial distributions of tidal energy resources before and after the deployment of tidal turbines near Pingtan Island, China. Considering factors such as the distribution of tidal stream energy, bathymetry, topography, and the design parameters of the turbines, an appropriate location for a demonstration tidal turbine was selected and the corresponding energy resource was evaluated. Several sites with strong tidal streams were considered: south of the northern cape, east of the southern cape, and the southern end of Haitan Bay. The former was thought most suitable for the deployment of a tidal energy turbine, with projected power generation for approximately 470 h per month. The average power of this demonstration was about 2.4 k W, and the annual electricity output was approximately 17.47 MWh. The intervention of the turbine device had little influence on the near-field tidal stream or water level. The tidal stream was reduced slightly in the area south of the northern cape, although the ef fect weakened further from the turbine. Conversely, the velocity increased slightly on both sides of the demonstration site. The dif ference in current speed with and without the turbine was greater at slack tide than still tide. The influence of turbine operation on water level was minor. The method adopted in this study can be considered a reference for the selection of sites for the demonstration of tidal stream energy. However, the method is unable describe the dynamic characteristics of the turbulent flow surrounding the deployed turbines, which has an important role regarding the optimal designs of the turbine blade and pile foundations. Therefore, we will continue to work to improve this model in future research.