A study on wetland classification model of remote sensing in the Sangjiang plain   总被引：1，自引：0，他引：1  

ZHANG Shu qing  ZHANG Shi kui  ZHANG Jun yan 《中国地理科学(英文版)》2000,10(1):68-73

1　ＩＮＴＯＤＵＣＴＩＯＮＷｅｔｌａｎｄｃａｎｐｅｒｆｏｒｍｅｎｏｒｍｏｕｓｆｕｎｃｔｉｏｎｓｉｎｒｅ ｓｏｕｒｃｅａｎｄｅｎｖｉｒｏｎｍｅｎｔａｄｊｕｓｔｍｅｎｔ ,ａｎｄｉｔｉｓｏｎｅｏｆｔｈｅｉｍｐｏｒｔａｎｔｅｃｏｌｏｇｉｃａｌｅｎｖｉｒｏｎｍｅｎｔｓｔｈａｔｈｕｍａｎｂｅ ｉｎｇｓｒｅｌｙｏｎ .Ｉｎｔｅｒｎａｔｉｏｎａｌｃｏｍｍｕｎｉｔｉｅｓｈａｖｅａｌｒｅａｄｙｐａｉｄ ｇｒｅａｔａｔｔｅｎｔｉｏｎｔｏｔｈｅｗｅｔｌａｎｄｒｅｓｅａｒｃｈ ,ａｎｄｓｏｍｅｆｏｒｅｉｇｎｅｒｓｈａｖｅｄｏｎｅ…  相似文献   

Assessment on the commonweal values of wetlands   总被引：2，自引：1，他引：1  

CUI Li-juan  PAN Li-li  Zhang Yan-bo 《中国地理科学(英文版)》2000,10(4):371-376

1THECOMPOSITIONOFWETLANDS'COMMONWEALVALUESThematterflow,energyflowandinformationflowgeneratedfromnaturalcapitalofwetlandsformecosystemcommonwealvalues.Theflowsaswellasartificialcapitalandlaborcapitalcommonlygeneratehumanitywelfare(COSTANZAetal.,1997).Generallyspeaking,thevaluesofwetlandsmaybedividedintothreetypes:directproductionvalues,valuesbroughtwithbiologicalfunctionsofwetlandsecosystem,andattributivevaluesaspartofsocialmakeup(BARBIER,1997).Thesevaluescannotallbeembod…  相似文献   

Habitat changes in coastal wetlands associated to hydrological changes in the watershed     

M.F. Carreño  M.A. Esteve  J. MartinezJ.A. Palazón  M.T. Pardo 《Estuarine, Coastal and Shelf Science》2008

In recent decades wetlands associated with the Mar Menor lagoon (SE Spain) have undergone several hydrological and biological changes as a consequence of increased water inputs from agricultural drainage off the watershed. Changes in the vegetal communities were studied by means of supervised classification of Landsat images, and TM and ETM+ sensors during the period 1984–2000, and a series of land cover maps was created. Changes in the wetland area during this period were analysed and a good fit was found with the total area of irrigated lands in the watershed. The series of land cover maps also allowed the study of the internal composition of the vegetal communities in each wetland. Important changes were detected, with an expansion of reedbeds and a significant reduction in the area occupied by priority habitats according to the Habitats Directive.  相似文献   

Topsoil morphology indicates bio-effective redox conditions in Venice salt marshes     

Friederike Lang  Moritz von der Lippe  Susanne Schimpel  Tiberio Scozzafava-Jaeger  Wolfgang Straub 《Estuarine, Coastal and Shelf Science》2010

Visual traces of iron reduction and oxidation are linked to the redox status of soils and have been used to characterise the quality of agricultural soils. We tested whether this feature could also be used to explain the spatial pattern of the natural vegetation of tidal habitats. If so, an easy assessment of the effect of rising sea level on tidal ecosystems would be possible. Our study was conducted at the salt marshes of the northern lagoon of Venice, which are strongly threatened by erosion and rising sea level and are part of the world heritage “Venice and its lagoon”. We analysed the abundance of plant species at 255 sampling points along a land–sea gradient. In addition, we surveyed the redox morphology (presence/absence of red iron oxide mottles in the greyish topsoil horizons) of the soils and the presence of disturbances. We used indicator species analysis, correlation trees and multivariate regression trees to analyse relations between soil properties and plant species distribution. Plant species with known sensitivity to anaerobic conditions (e.g. Halimione portulacoides) were identified as indicators for oxic soils (showing iron oxide mottles within a greyish soil matrix). Plant species that tolerate a low redox potential (e.g. Spartina maritima) were identified as indicators for anoxic soils (greyish matrix without oxide mottles). Correlation trees and multivariate regression trees indicate the dominant role of the redox morphology of the soils in plant species distribution. In addition, the distance from the mainland and the presence of disturbances were identified as tree-splitting variables. The small-scale variation of oxygen availability plays a key role for the biodiversity of salt marsh ecosystems. Our results suggest that the redox morphology of salt marsh soils indicates the plant availability of oxygen. Thus, the consideration of this indicator may enable an understanding of the heterogeneity of biological processes in oxygen-limited systems and may be a sensitive and easy-to-use tool to assess human impacts on salt marsh ecosystems.  相似文献   

Sedimentation within and among mangrove forests along a gradient of geomorphological settings     

María Fernanda Adame  David Neil  Sara F. Wright  Catherine E. Lovelock 《Estuarine, Coastal and Shelf Science》2010

Coastal wetlands provide important ecological services to the coastal zone, one of which is sediment retention. In this study we investigated sediment retention across a range of geomorphological settings and across vegetation zones comprising coastal wetlands. We selected six coastal wetlands dominated by mangroves over a gradient from riverine to tidal settings in Southeast Queensland, Australia. Each site was comprised of three distinct vegetation communities distributed as parallel zones to the coast line: seaward fringe mangroves, landward scrub mangroves and saltmarsh/ cyanobacteria mat of the high intertidal zone. We measured suspended sediment retention and sedimentation rates. Additionally, in order to assess the origin of sediment transported and deposited in the mangroves, glomalin, a novel terrestrial soil carbon tracer, was used. Our results show a mean average sedimentation of 0.64 ± 0.01 mg cm⁻² spring tide⁻¹, which was variable within sites, regardless of geomorphological setting. However, geomorphological setting influenced spatial patterns of sediment deposition. Riverine mangroves had a more homogeneous distribution of sediments across the intertidal zone than tidal mangroves, where most sedimentation occurred in the fringe zone. Overall, the fringe zone retained the majority of sediment entering the coastal wetland during a tidal cycle with 0.90 ± 0.22 mg cm⁻² spring tide⁻¹, accounting for 52.5 ± 12.5% of the total sedimentation. The presence of glomalin in suspended sediments, and thus the relative importance of terrigenous sediment, was strongly influenced by geomorphological setting, with riverine mangroves receiving more glomalin in suspended solids than tidal mangroves. Glomalin was also differentially deposited within the vegetation zones at different geomorphological settings: primarily at the fringe zone of tidal mangroves and within the scrub zone of riverine mangroves. The differences we observed in the spatial distribution of sedimentation and the difference in the origin of the sediment deposited in riverine and tidal mangroves are likely to have an impact on ecological processes.  相似文献   

滨海湿地生态旅游资源评价研究   总被引：1，自引：0，他引：1  

庄晨辉  李闽丽  张惠光  陈星 《亚热带资源与环境学报》2007,2(1):81-87

在研究旅游资源评价与湿地资源评价已有成果的基础上,提出滨海湿地生态旅游资源评价及评价指标选取的基本原则,并从客观实际出发,应用层次分析法(AHP),从生态环境、旅游资源和旅游开发三方面着手,构建了滨海湿地生态旅游资源评价体系,并据此进行计算机处理、排序和检验,提出滨海湿地生态旅游资源等级指标及赋分标准,为科学评价滨海湿地生态旅游资源提供依据.  相似文献   

盐城滨海湿地景观变化分段研究     

闫文文  谷东起  吴桑云  明洁 《海岸工程》2011,30(1):68-78

在ERDAS、ArcGIS等软件支持下,利用3S技术将1期研究区植被分布图和3期遥感影像,提取出4期盐城滨海湿地景观分布图,并对这4期的湿地景现属性数据进行分段对比,即按照控制研究区湿地景观分布的不同影响因素,将研究区从北向南分为3段区域进行对比分析.结果表明:盐城滨海湿地在1980-2008年期间,自然景观,包括河口...  相似文献   

Analysis of growing season carbon and water fluxes of a subalpine wetland in the Canadian Rocky Mountains: Implications of shade on ecosystem water use efficiency     

Dylan M. Hrach  Richard M. Petrone  Adam Green  Myroslava Khomik 《水文研究》2022,36(1):e14425

Mountain regions are an important regulator in the global water cycle through their disproportionate water contribution. Often referred to as the “Water Towers of the World”, mountains contribute 40%–60% of the world's annual surface flow. Shade is a common feature in mountains, where complex terrain cycles land surfaces in and out of shadows over daily and seasonal scales, which can impact water use. This study investigated the turbulent water and carbon dioxide (CO₂) fluxes during the snow-free period in a subalpine wetland in the Canadian Rocky Mountains, from 7 June to 10 September 2018. Shading had a significant and substantial effect on water and CO₂ fluxes at our site. When considering data from the entire study period, each hourly increase of shade per day reduced evapotranspiration (ET) and gross primary production (GPP) by 0.42 mm and 0.77 g C m^?2, equivalent to 17% and 15% per day, respectively. However, the variability in shading changed throughout the study, it was stable to start and increased towards the end. Only during the peak growing season, the site experienced days with both stable and increasing shade. During this time, we found that shade, caused by the local complex terrain, reduced ET and potentially increased GPP, likely due to enhanced diffuse radiation. The overall result was greater water use efficiency during periods of increased shading in the peak growing season. These findings suggest that shaded subalpine wetlands can store large volumes of water for late season runoff and are productive through short growing seasons.  相似文献