Coastal Zone Of China Research Articles

Effects of Organic Pollutants on the Bacterioplankton Community in Hangzhou Bay

Hangzhou Bay suffers from intensive anthropogenic disturbances and a huge amount of terrestrial inputs, and thus has become one of the most seriously contaminated coastal zones in China. There is evidence that microbes play a dominant role in pollutant biodegradation and serve as biomarkers for pollution levels. However, it remains unclear how the bacterioplankton communities respond to organic contaminants. To fill this knowledge gap, we collected surface water samples (0.5 m below the surface layer) from 13 sites across Hangzhou Bay and 8 control sites across its adjacent offshore areas. Using Illumina sequencing based on analysis of the bacterial 16S rRNA gene, we explored the effects of increasing organic pollution levels on the bacterioplankton community compositions (BCCs). The results revealed that the organic pollution level (A) in Hangzhou Bay (13.2±1.6) was significantly (P<0.001) higher than in the control zone (5.4±3.0). The distribution and diversity of bacterioplankton communities were significantly distinct between the two zones. The dominant bacterioplankton lineages in Hangzhou Bay were γ-Proteobacteria (24.4%±5.5%), α-Proteobacteria (16.5%±7.7%), and Planctomycetes (13.9%±8.6%), whereas those in the adjacent zones were Cyanobacteria (20.1%±7.5%), Bacteroidetes (18.4%±1.5%), Actinobacteria (17.5%±4.2%), γ-Proteobacteria (16.6%±1.2%), and α-Proteobacteria (14.3%±1.7%). Multivariate regression tree (MRT) analysis showed that the bacterioplankton community diversity was primarily affected by suspended particulates (SP), nitrite, oil, and organic pollutants, which respectively explained 22.0%, 6.5%, 6.0%, and 5.5% of the variance in diversity. Redundancy analysis (RDA) illustrated that the bacterioplankton community distribution was controlled by organic pollutants, COD, Chla, TN, nitrate, and salinity, which cumulatively governed 71.0% of the variation in BCCs. Organic pollutants alone controlled 6.5% variance, which was higher than any other single factor. Additionally, 35 sensitive species were identified via the indicator value method and their relative abundances were significantly associated (P<0.05 in each case) with the organic pollution level, thereby indicating their potential for evaluating coastal pollution. Collectively, our work demonstrates that BCCs are sensitive to coastal pollution and provides biomarkers for elevated pollution levels.

Spatiotemporal evolution of carbon sequestration vulnerability and its relationship with urbanization in China's coastal zone

Carbon sequestration plays a vital role in maintaining the stability of global climate and the carbon cycle, but is undergoing significant changes due to urbanization. This study proposes the concept of carbon sequestration vulnerability (CSV), and explores the spatiotemporal evolution of CSV and its relationship between urbanization in China's coastal zone from 2000 to 2010. The study results provide a scientific basis for government management and policy-making. The results showed that the average amount of CSV in 2000 and 2010 was 0.301 and 0.279, respectively, in China's coastal zone and exhibited obvious spatial heterogeneity. Land urbanization had better interpretation strength for CSV than population and economic urbanization indexes, and could explain the 10-year change in CSV well in China's coastal zone. In China's coastal zone from 2000 to 2010, CSV response to land urbanization was proven to be positive and linearly increasing, and the slope of the linear relationship was 0.4214, cities with high land urbanization level have higher CSV; likewise, the change in land urbanization level had a significant positive and linear relationship with the change in CSV, and the slope of the linear relationship was 0.5031. When the city's land urbanization level increased by <6.8% over ten years, the CSV declined, and conversely, the CSV rose. For the goal of reduce CSV of cities, government and policy-makers should focus on land urbanization and it is possible to realize the goal by controlling land urbanization below 6.8% every ten years.

Fluxes of carbon dioxide and methane across the water–atmosphere interface of aquaculture shrimp ponds in two subtropical estuaries: The effect of temperature, substrate, salinity and nitrate

While aquaculture pond is a dominant land use/cover type and a distinct aquatic ecosystem in the coastal zones of China and southeast Asia, their contributions to the fluxes of greenhouse gases (GHGs) have only been poorly quantified. Fluxes of CO2 and CH4 in the shrimp ponds with different salinities were simultaneously measured in situ using the floating chamber technique in two different subtropical estuaries, namely, the Min River Estuary (MRE) and Jiulong River Estuary (JRE). The average CO2 and CH4 fluxes in the shrimp ponds over the observation periods varied from −2.09 to 3.37mmol CO2 m−2h−1 and from 0.28 to 16.28mmol CH4 m−2h−1, respectively, with higher fluxes being detected during the middle stage of aquaculture. The temporal variation of CO2 and CH4 fluxes in both estuaries ponds closely followed the seasonal cycle of temperature. Higher CH4 emissions were observed in MRE ponds than in JRE ponds because of the lower water salinity and N-NO3− concentrations as well as a greater supply of carbon substrates. Our findings suggested that shrimp ponds were CH4 emission “hotspots” in the subtropical estuaries of China. Based on a new global warming potential model, we conservatively estimated an anuual GHG emission rate of approximately 63.68Tg CO2-eq during the culture period from aquaculture ponds across the subtropical estuaries of China. Our results demonstrate the importance of aquaculture ponds as a major GHG source and a contributor to climate warming in the subtropical estuarine regions of China, and call for effective regulation of GHG emissions from these ponds for climate mitigation in future.

生境异质性及源株密度对互花米草入侵力的影响

PDF HTML阅读 XML下载 导出引用 引用提醒 生境异质性及源株密度对互花米草入侵力的影响 DOI: 10.5846/stxb201803300702 作者: 作者单位: 华东师范大学,华东师范大学,华东师范大学,华东师范大学,华东师范大学,华东师范大学,华东师范大学 作者简介: 通讯作者: 中图分类号: 基金项目: 国家重点研发计划项目（2016YFC1201100，2017YFC0506000）；上海市科委科研计划项目（17DZ1201902，18DZ1204802）；河口海岸学国家重点实验室科研业务费（SKLEC-DWJS201802）；浦东新区科技发展基金（PKJ2016-C03） Effects of habitat heterogeneity and ortet density on the invasiveness of Spartina alterniflora Author: Affiliation: East China Normal University,East China Normal University,East China Normal University,East China Normal University,East China Normal University,East China Normal University,East China Normal University Fund Project: The National Key R&D Program of China (2016YFC1201100，2017YFC0506000)，Scientific research project project of Shanghai Municipal Science and Technology Commission (17DZ1201902)，the State Key Lab of Estuarine and Coastal Research (SKLEC-DWJS201802) 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:外来物种互花米草（Spartina alterniflora）被引种到我国海岸带后，已带来一系列生态危害，严重影响了入侵地生态系统结构和功能，深入了解其入侵机制是实施有效控制的基础和理论依据。长江口的滩涂湿地是我国典型的异质潮滩，拥有多种生境。为了探究异质潮滩环境中互花米草初始源株对其入侵力的影响，研究通过野外移栽实验，模拟不同源株密度，探讨潮滩湿地生境异质性及源株密度对互花米草定居、生长和扩散的影响。结果表明：1）生境异质性及源株密度均对互花米草存活率、株高及种群增长率有极显著影响（P < 0.01）。2）至生长季末，植被区内互花米草存活率、株高均显著高于前沿光滩（P < 0.05）。此外，淤泥质潮滩植被区内互花米草株高、种群增长率也显著高于粉砂质潮滩植被区（P < 0.05）。3）互花米草入侵植被区不受源株密度的限制，但随源株密度增加，互花米草种群增长率显著降低（P < 0.05），而株高无显著差异（P > 0.05）；在光滩区，只有高源株密度才可入侵成功。4）异质生境的冲淤动态、淹水时间和淹水深度是影响互花米草存活和生长的主要环境因子。丰富了河口湿地互花米草入侵力的机理研究，也为我国开展互花米草防控及海岸带保护、修复和管理提供了科学依据，具有重要的理论和实践意义。 Abstract:After being introduced into China's coastal zone, the exotic species, Spartina alterniflora, has resulted in a series of ecological risks and seriously influenced the structure and function of the native ecosystem. Understanding the invasion mechanisms of S. alterniflora is the theoretical basis for its effective control. The estuarine wetland in the Yangtze Estuary, China, is a typical heterogeneous tidal flat with a variety of habitats. In this study, the effects of habitat heterogeneity and ortet density on the colonization, growth, and dispersal of S. alterniflora were studied using field experiments. The results were as follows:1) habitat heterogeneity and ortet density have significant effects on the survival rate, plant height, and population growth rate of S. alterniflora (P < 0.01); 2) at the end of the growing season, the survival rate and height of S. alterniflora in the vegetation area were significantly higher than that in the mudflat (P < 0.05). In addition, the height and population growth rate of S. alterniflora in the muddy tidal flat were significantly higher than that in the silty tidal flat (P < 0.05); 3) the invasion of S. alterniflora in the vegetation area was not limited by ortet density. The growth rate of the S. alterniflora population in vegetation area decreased significantly with increased ortet density (P < 0.05), but the plant height had no significant difference (P > 0.05). In addition, only the higher density S. alterniflora rhizomes could invade the mudflat successfully; 4) the sediment disturbance regimes, flooding time, and flooding depth are the key environmental factors that affected S. alterniflora survival and growth. This study enhances the understanding of S. alterniflora invasive mechanisms in coastal wetlands, and provides a scientific basis for the control of S. alterniflora, as well as the protection, restoration, and management of the coastal zone in China. 参考文献 相似文献 引证文献

Spatial and temporal trends of short- and medium-chain chlorinated paraffins in sediments off the urbanized coastal zones in China and Japan: A comparison study

To examine the impacts of urbanization and industrialization on the coastal environment, and assess the effectiveness of control measures on the contamination by chlorinated paraffins (CPs) in East Asia, surface and core sediments were sampled from the urbanized coastal zones in China and Japan (i.e., Pearl River Delta (PRD), Hong Kong waters and Tokyo Bay) and analyzed for short-chain (SCCPs) and medium-chain CPs (MCCPs). Much higher concentrations of CPs were found in the industrialized PRD than in adjacent Hong Kong waters. Significant correlation between CP concentration and population density in the coastal district of Hong Kong was observed (r2 = 0.72 for SCCPs and 0.55 for MCCPs, p < 0.05), highlighting the effect of urbanization. By contrast, a relatively lower pollution level of CPs was detected in Tokyo Bay. More long-chain groups within SCCPs in the PRD than in Hong Kong waters and Tokyo Bay implied the effect of industrialization. Comparison of temporal trends between Hong Kong outer harbor with Tokyo Bay shows the striking difference in historical deposition of CPs under different regulatory situations in China and Japan. For the first time, the declining CP concentrations in Tokyo Bay, Japan, attest to the effectiveness of emissions controls.

Position precision evaluation of ZY-3 satellite image in the coastal zone of China

With China's coastal zone as the research area,6 ZY- 3 sensor corrected products were chosen for evaluation,which covered Qingdao of Shandong,Yancheng of Jiangsu and Wenzhou of Zhejiang from north to south. The authors used high accuracy GPS points to evaluate the autonomous positioning precision in comparison with SPOT5 images. Then DOMs were generated with high accuracy GPS points as ground control points( GCPs)and national 1∶ 50 000 DEM products,and the influences of the quantity and distribution of GCPs were analyzed.The results show that the average autonomous positioning precision of ZY- 3 panchromatic image and that of multispectral image are 19. 6 m and 23. 0 m,respectively. The autonomous positioning precisions of ZY- 3panchromatic image and multispectral image are better than the precision of SPOT5 images. With 1 GCP at the four corners,the positioning precision of DOM is less than 2 pixels. With 4 GCPs,the positioning precision of DOM is about 1 pixel. With 2 landside corner GCPs,the positioning precision of DOM is less than 3 m. With 3 landside GCPs,the positioning precision of DOM is lower than that of 2 landside GCPs,especially at the seaside. The results show that,with a few GCPs,ZY- 3 DOM can reach high accuracy and satisfy the need of coastal zone remote sensing survey.

Spatial-temporal characteristics of land use intensity of coastal zone in China during 2000–2010

Based on remote sensing and GIS techniques, land use maps in 2000, 2005 and 2010 in China’s coastal zone were produced, and structural raster data of land use were further generated to calculate land use intensity comprehensive index (LUICI) for analyzing land use spatial-temporal characteristics at 1 km scale. Results show that: 1) from the perspective of spatial patterns of landforms at a macro scale, there is a significant difference in land use intensity between the north and the south of China’s coastal zone. Hotspots of changes mainly concentrated in metropolitan areas, estuaries and coastal wetlands; 2) elevation is an important factor that controlling land use spatial patterns at local scale. Land use intensity is much higher within areas below the elevation of 400 m and it decreased significantly as the elevation increasing; 3) there is a significant land-ocean gradient for land use intensity, which is low in island and near-shore areas, but high in the regions that 4–30 km far away the coastline because of much intensive human activities; however, in recent decades land use intensity had been promoted significantly in low near-shore area due to extensive sea reclamations; 4) significant differences of land use intensity were also found among provincial administrative units. A rising trend of land use intensity was found in provincial-level administrative units from 2000 to 2010. To sum up, elevation, land-ocean gradient, socio-economic status and policy are all influencing factors to the spatial patterns and temporal variations of land use intensity in China’s coastal zone.

Ecological risk caused by land use change in the coastal zone: a case study in the Yellow River Delta High-Efficiency Ecological Economic Zone

China's coastal zone plays an important role in ecological services production and social-economic development; however, extensive and intensive land resource utilization and land use change have lead to high ecological risk in this area during last decade. Regional ecological risk assessment can provide fundamental knowledge and scientific basis for better understanding of the relationship between regional landscape ecosystem and human activities or climate changes, facilitating the optimization strategy of land use structure and improving the ecological risk prevention capability. In this paper, the Yellow River Delta High-Efficiency Ecological Economic Zone is selected as the study site, which is undergoing a new round of coastal zone exploitation and has endured substantial land use change in the past decade. Land use maps of 2000, 2005 and 2010 were generated based on Landsat images by visual interpretation method, and the ecological risk index was then calculated. The index was 0.3314, 0.3461 and 0.3176 in 2000, 2005 and 2010 respectively, which showed a positive transition of regional ecological risk in 2005.

A comprehensive risk analysis of coastal zones in China

Although coastal zones occupy an important position in the world development, they face high risks and vulnerability to natural disasters because of their special locations and their high population density. In order to estimate their capability for crisis-response, various models have been established. However, those studies mainly focused on natural factors or conditions, which could not reflect the social vulnerability and regional disparities of coastal zones. Drawing lessons from the experiences of the United Nations Environment Programme (UNEP), this paper presents a comprehensive assessment strategy based on the mechanism of Risk Matrix Approach (RMA), which includes two aspects that are further composed of five second-class indicators. The first aspect, the probability phase, consists of indicators of economic conditions, social development, and living standards, while the second one, the severity phase, is comprised of geographic exposure and natural disasters. After weighing all of the above indicators by applying the Analytic Hierarchy Process (AHP) and Delphi Method, the paper uses the comprehensive assessment strategy to analyze the risk indices of 50 coastal cities in China. The analytical results are presented in ESRI ArcGis10.1, which generates six different risk maps covering the aspects of economy, society, life, environment, disasters, and an overall assessment of the five areas. Furthermore, the study also investigates the spatial pattern of these risk maps, with detailed discussion and analysis of different risks in coastal cities.

Human settlement and regional development in the context of climate change: a spatial analysis of low elevation coastal zones in China

Low elevation coastal zone (LECZ) in China is densely populated and economically developed, which is exposed to increasing risks of hazards related to climate change and sea level rise. To mitigate risks and achieve sustainable development, we need to better understand LECZ. As the first step, in this paper we define the extent of the LECZ in China, and analyze the spatial distribution of LECZ and its population, using a geographic information system software (ArcGIS) to combine elevation models and population data sets. Our findings show that, overall, this zone covers 2.0 % of China’s land area but contains 12.3 % of the total population, which is the largest population living in LECZ in the world. There are large regional variations in the distribution of both LECZ and LECZ population, with half of the LECZ within 30 km from the coastline, and Jiangsu Province having the largest LECZ area and population. The LECZ is also concentrated in three major economic zones in China, which accounts for 54 % of LECZ and three quarters of all LECZ population in China. The impact of future climate change on China’s LECZ is exacerbated by rapid economic and population growth, urbanization and environmental degradation. Coordinating development in coastal and inland China, enhancing adaptive capacity and implementing integrated risk management for LECZ are needed to reduce the risks related to climate change and to achieve sustainable development.

Existing Form and Causes of Bay Facies Organic Sand

Recent years, massive projects construct in coastal zone in china , but soil in these coastal areas often contain organic matter.And the high levels of organic matter reduced soil strength which consolidated by concrete mixing pile.This paper take the organic sand as the research object,analysis the formation of such organic sand by electron microscopy scanning and indoor experiments.

Study on Coastal Zone Sustainable Development and its Application

Rapid industrialization and urbanization development had brought a serious challenge for coastal zone in China. A coastal management model had been set up for coastal zone, the coordination degree and coordinated development model were adopted to analyze the development trend. The results show that the gap between the environment comprehensive efficiency index and economic efficiency index is getting bigger and bigger for Bohai Bay coastal zone.

The Design and Research of the Information Management System of Geological Hazards in China Coastal Zone based on ArcEngine

The study was based on the development platform of Visual Basic 6.0.The secondary development of GIS was progressed by ArcEngine 9.3 component library of ESRI,analyzing the actual demand of geological hazards information management in China coastal zone.The information management system of geological hazards in China coastal zone was established.The system had the functions including the query and management of spatial data and attribute data,space statistical analysis,thematic maps drawing and hazard assessment,data conversion and output,etc.It provided the integrated services for geologic hazard prediction,forecast and prevention.

Clustering Analysis of Hydrologic Type in Coastal Zone

By the analyzing of Q cluster and characteristic factor matrix, coastal hydrological types and their distributions are found by selecting 7 characteristic factors in 26 districts of the China coastal zone. In the view of environmental hydrology and marine engineering, the distribution types of coastal zone are mainly divided into sedimentary coast (including sandy coast, muddy coast, strongly hydrodynamic coast) and rocky coast (including massive bedrock coast, grit bedrock coast, bank slope and platform coast). The formation, development and evolution of the coastal zone are mainly controlled by the land geologic actions, particularly by tectonism and hydraulic condition, and the ocean geologic actions only take part in the modification of the coastal features. The topography and lithology are mainly controlled by distribution of land water flow in coastal zone.

High wintertime particulate matter pollution over an offshore island (Kinmen) off southeastern China: An overview

Both the Yangtze River Delta (YRD) and the Pearl River Delta (PRD), the two most rapidly developing areas in eastern China, have suffered from serious air pollution, and thus, numerous investigations were devoted to studying these problems. Other areas in eastern China have received less attention despite similar rapid development in their industries and economy. In this study, we analyzed air‐quality data from Kinmen Island (24°27′26″N, 118°19′36″E) located off Fujian Province and between the two above‐mentioned deltas. Our results clearly show that the study area is experiencing serious air quality deterioration. Particularly, high levels of suspended particulate matter (PM) were observed during winter, when the northeasterly monsoon prevails. For example, concentrations of wintertime PM10 (particles ≤ 10 μm in diameter) frequently exceeded 100 μg/m3 in the last three years. In addition to the air‐quality data analysis, aerosol samples were collected between 22 November 2007 and 6 March 2008 and subjected to chemical analyses of various species. Our findings show that the three principal PM components include organic, mineral, and sulfate species with moderate to minor fractions of nitrate, sea salt, elemental carbon, and trace metal oxides. The high PM levels observed over the island may be partly attributed to the transport from a mixed‐type industrial area located ∼40 km northeast of Kinmen. Our study could partially fill the air quality data gap between the YRD and PRD regions, and highlight the alarming fact that air pollution has gradually expanded along eastern China's coastal zone.

Assessing water renewal of the northern coastal zone in China using a variable fuzzy pattern recognition model

An integrated indexes system for assessing water renewal of the northern coastal zone is developed; and rough sets theory is used to eliminate the redundancy in the indexes system. Then a variable fuzzy pattern recognition model is selected to evaluate the state of water renewal, which involves fuzzy information and interval numbers of classification standard values for evaluation. The indexes system and evaluation model are illustrated in water renewal evaluation of Dalian City. The results of the recent ten years show that natural renewal is much lower than social renewal. The evaluation result of the planning year implies that measures including increasing efficiency of water consumption, increasing use of reclaimed water amounts, desalinated water and seawater, and use of trans-basin water work are effective for improving social renewal; furthermore, water use of trans-basin work is the most sensitive factor influencing social renewal, and other measures including use of reclaimed water, water-saving of urban living, use of seawater for industry, water-saving of agriculture and water-saving of industry are in sequence of sensitivity.

Assessment of coastal management options by means of multilayered ecosystem models

This paper presents a multilayered ecosystem modelling approach that combines the simulation of the biogeochemistry of a coastal ecosystem with the simulation of the main forcing functions, such as catchment loading and aquaculture activities. This approach was developed as a tool for sustainable management of coastal ecosystems. A key feature is to simulate management scenarios that account for changes in multiple uses and enable assessment of cumulative impacts of coastal activities. The model was applied to a coastal zone in China with large aquaculture production and multiple catchment uses, and where management efforts to improve water quality are under way. Development scenarios designed in conjunction with local managers and aquaculture producers include the reduction of fish cages and treatment of wastewater. Despite the reduction in nutrient loading simulated in three different scenarios, inorganic nutrient concentrations in the bay were predicted to exceed the thresholds for poor quality defined by Chinese seawater quality legislation. For all scenarios there is still a Moderate High to High nutrient loading from the catchment, so further reductions might be enacted, together with additional decreases in fish cage culture. The model predicts that overall, shellfish production decreases by 10%–28% using any of these development scenarios, principally because shellfish growth is being sustained by the substances to be reduced for improvement of water quality. The model outcomes indicate that this may be counteracted by zoning of shellfish aquaculture at the ecosystem level in order to optimize trade-offs between productivity and environmental effects. The present case study exemplifies the value of multilayered ecosystem modelling as a tool for Integrated Coastal Zone Management and for the adoption of ecosystem approaches for marine resource management. This modelling approach can be applied worldwide, and may be particularly useful for the application of coastal management regulation, for instance in the implementation of the European Marine Strategy Framework Directive.

Morphodynamic responses to the deep water harbor development in the Caofeidian sea area, China's Bohai Bay

Vast bay-type tidal inlets can be found along the coastal zones of China. They are generally suitable for deep water channels and large harbors because of the presence of large water depth and good mooring conditions. The deep channel, in front of the head of Caofeidian Island in Bohai Bay, China, is a typical bay-type tidal inlet system. The tidal current, a type of reverse flow, makes the key contribution to maintain the deep water depth. The co-action of waves and tidal currents is the main dynamic force for sediment motion. Waves have significant influence on the sediment concentration. Based on the characteristics of waves, tidal currents, sediment and seabed evolution in Caofeidian sea area, a 2D mathematical model for sediment transport under influence of waves and tidal currents is developed to study the development schemes of the Caofeidian Harbor. The model has been verified for spring and neap tides, in winter as well as in summer of 2006. The calculated tidal stages, flow velocities, flow directions and sediment concentrations at 15 stations are in good agreement with the observations. Furthermore, the calculated data on pattern and magnitude of sedimentation and erosion in the related area agree well with the observations. This model has been used to study the effects of the reclamation scheme for Caofeidian Harbor on the hydrodynamic environment, sediment transport and morphological changes. Attentions are paid to the project inducing changes of flow velocities and morphology in the deep channel at the south side of Caofeidian foreland, in the Laolonggou channel and in various harbor basins. The conclusions can provide the important foundation for the protection and use of bay-type tidal inlets and the development of harbor industry.

Impacts of an alien species ( Spartina alterniflora) on the macrobenthos community of Jiangsu coastal inter-tidal ecosystem

Spartina alterniflora, a species vegetating on inter-tidal flats that was introduced from the eastern coast of United States, has become a hot topic, focusing on its invasion within local species in the coastal zone of China. Impacts of S. alterniflora on the inter-tidal macrobenthos community in the Jiangsu coastland are addressed by comparing the macrobenthos characteristics in a mudflat and in a four-year-old Spartina salt marsh that had earlier been a mudflat. During the period October 2002–July 2003, we studied the distribution pattern and diversity of macrobenthos, and discussed their correlation with environmental factors caused by Spartina vegetation. The results showed that a total of 43 macrobenthos species were found, mainly consisting of Mollusca, Crustacea, and Annelida. Ten macrobenthos species were found in the Spartina salt marsh, and 36 species were found in the mudflat. Life forms and functional groups of macrobenthos in the Spartina salt marsh were obviously distrinct from that of the mudflat. The study showed that macrobenthos diversity in the Spartina salt marsh decreased, and the community structure altered obviously, whereas the biomass showed no differences in different seasons. Statistical analysis demonstrated that seasonal change of macrobenthos diversity in the Spartina salt marsh negatively related to content of sediment organic matter, total N, bulk density, height and biomass of Spartina vegetation, and positively related to the density of Spartina. All these differences suggested the obvious effects of the Spartina vegetation on the Jiangsu inter-tidal benthic macroinvertebrate ecology. Furthermore, the investigation also showed that the niche of the native macrobenthos living in the mudflat has been transferred down, seaward, due to the invasion of Spartina in our study site.

Potential of Multitemporal ERS-2 SAR Imagery for Land Use Mapping in Coastal Zone of Shangyu City, China

Abstract Scarce land resources and growing population are compelling issues for intensively developing coastal zones in China. During the past 30 years, many coastal tidelands have been enclosed for cultivation and development. To plan and implement large-scale reclamation programs in coastal zones, timely and reliable information concerning the nature, extent and physicochemical characteristics of the coastal saline soils land is essential. Because extracting useful information from optical remote sensing imagery is often hampered by the presence of clouds and wet weather, in this study we used multitemporal European remote sensing satellite (ERS)–2 PRI synthetic aperture radar (SAR) images only for coastal land use mapping. The SAR multitemporal backscattering characteristics of main land use categories were first investigated after pseudocolor synthesizing of three temporal SAR images, extracting dikes and partitioning the study area into six subzones according to the reclamation years. Next, an iterat...