三大沿海城市群滨海湿地的陆源人类活动影响模式

随着陆源人类活动对滨海湿地的干扰日益强烈,研究滨海湿地陆源人类活动影响规律对于滨海湿地资源管理和保护具有重要的现实意义.以我国三大沿海城市群(环渤海湾、长江三角洲、珠江三角洲)滨海湿地为研究对象,分别选取围海造地(直接因子)和流域污染物(营养盐、非点源无机污染物)输入(间接因子)表征1990-2000年间滨海湿地的陆源人类活动影响强度及规律.研究发现,虽然围海造地仍然以农业用地为主(＞50％),但城市建设用地比例随人口城市化率增高而增加,以珠江三角洲城市群最高;在环渤海湾和珠江三角洲城市群区域超过60％的滨海湿地面积受到高或中等污染物输入强度影响,长江三角洲城市群区域则有44.7％的滨海湿地面积处于中等污染物输入强度及以上.通过叠加围海造地和污染物输入双重陆源人类活动的综合影响强度表明,珠江三角洲城市群平均强度指数达到0.79,且处于中等及以上影响强度区域面积比例达到78％,均高于其他两个城市群滨海湿地区域.空间分析结果表明,陆源人类活动对滨海湿地的强影响区域多集中分布于河流人海口、较为发达城市滨海区以及海岸线附近.     

三江平原流域湿地景观破碎化过程研究

以流域为研究单元,利用历史图件和遥感数据资料及GIS技术,系统分析了该区典型流域50年来湿地景观的破碎化过程.结果表明,该区湿地景观破碎化在斑块个体和空间结构两方面变化极大.景观斑块个体变化主要表现为最大斑块、平均斑块面积不断缩小,斑块密度不断增大,斑块形状破碎化指数不断增大,景观内部生境面积破碎化指数不断上升;空间结构变化主要表现为湿地景观由初始基质景观逐渐变为河岸带景观;同时,随着农田面积逐渐扩大,隔离湿地斑体数量不断上升,隔离度不断增大;景观空间分布模式由“大陆-岛屿模式”向“卫星型模式”转变,最后变化为“完全隔离型模式”.导致该区湿地景观破碎化的主导因素是大规模的农业开发,反映了人类活动对湿地景观的巨大影响.     

黄河三角洲湿地生态系统的形成及其保护

通过对黄河三角洲新生湿地的野外调查,利用TM陆地卫星影像图的判读,结合黄河尾闾变动的历史资料分析,结果表明,黄河三角洲新生湿地是多泥沙的黄河淤积和海岸蚀退所形成.受区域气候、地貌、地质沉积、土壤、植被的相互作用和互相影响,形成4.5×105hm2的湿地,其中有6.84×104hm2的人工湿地.湿地生态类型随着黄河尾闾摆动和海退陆进程度而变化,自海洋向陆地依次为潮下带水生生态系统潮间带湿地生态系统潮上带盐生生态系统芦苇獐茅湿地生态系统草甸湿地生态系统陆上农田生态系统.该系统资源丰富,共有野生动物1524种,鸟类300种,鱼类1040种.石油开发和近年来黄河断流对湿地产生一定影响,应在开发利用中加强管理和保护     

Estimating phosphorus retention of existing and restored coastal wetlands in a tributary watershed of the Laurentian Great Lakes in Michigan,USA

Simulation modeling with uncertainty analysis was applied to the question of nonpoint source pollution control through extensive wetland restoration. The model was applied to the Quanicassee River basin, a tributary stream to Saginaw Bay on Lake Huron in northeastern Michigan, USA. An estimate of the role of the existing 695 ha of riverside and lake-side wetlands in the lower Quanicassee River basin suggests that they retain 1.2 metric tons of phosphorus per year (mt P/yr), or 2.5% of the total phosphorus load from the basin. A simple Vollenweider-type model of phosphorus retention by created wetlands, calibrated with 3-years of data from two wetland sites in Midwestern USA, was used to estimate the effect of major wetland restoration in the basin. For a wetland restoration project involving 15% of the Quanicassee River basin or 3,120 ha of wetlands, an estimated 33 mt P/yr could be retained, assuming a proper hydrologic connection between the wetlands and the river. This would represent a reduction of two-thirds of the existing phosphorus load to the Bay from the Quanicassee River basin. Large-scale wetland restoration appears to be a viable management practice for controlling phosphorus and other nonpoint source pollution from entering Saginaw Bay. It is an alternative that meets two major resource goals – developing wetland habitat and controlling pollution to the Great Lakes.     

黄河三角洲湿地生态系统的形成及其保护

通过对黄河三角洲新生湿地的野外调查,利用TM陆地卫星影像图的判读,结合黄河尾闾变动的历史资料分析,结果表明,黄河三角洲新生湿地是多泥沙的黄河淤积和海岸蚀退所形成.受区域气候、地貌、地质沉积、土壤、植被的相互作用和互相影响,形成4.5×10⁵hm²的湿地,其中有6.84×10⁴hm²的人工湿地.湿地生态类型随着黄河尾闾摆动和海退陆进程度而变化,自海洋向陆地依次为潮下带水生生态系统潮间带湿地生态系统潮上带盐生生态系统芦苇獐茅湿地生态系统草甸湿地生态系统陆上农田生态系统.该系统资源丰富,共有野生动物1524种,鸟类300种,鱼类1040种.石油开发和近年来黄河断流对湿地产生一定影响,应在开发利用中加强管理和保护.     

三江平原残存湿地斑块特征及其对物种多样性的影响

景观破碎化是当前一个突出的生态学问题,破碎斑块的大小和形状特征对物种多样性具有重要影响。选取三江平原别拉洪河流域为研究区,通过调查残存湿地斑块的面积、形状和植物物种丰富度,利用相关分析和回归分析等方法研究了残存湿地斑块特征及其对物种多样性的影响。研究结果表明:在强烈的人为活动干扰下,三江平原湿地破碎化严重,残存湿地斑块面积较小,斑块形状规则、边界简单。斑块形状指数、分维数、形状特征点数和斑块面积、物种丰富度均没有显著相关关系,而斑块面积、周长和周长面积比对物种丰富度具有显著影响。但是斑块周长和周长面积比均受面积的直接影响,所以斑块面积是决定物种丰富度的主要因素,这点需在湿地生物多样性保护中予以重视。虽然斑块形状特征点数是农业景观物种丰富度的一个很好预测指标,但是该指标不适用于形状规则的残存湿地斑块物种丰富度预测。另外,对于残存湿地斑块种-面积关系的机理还有待进一步研究。     

滨海湿地生态系统土壤微生物及其影响因素研究综述

土壤微生物是滨海湿地生态系统中不可或缺的关键组分,在土壤发育、物质循环和污染物净化等诸多土壤生态过程中发挥着重要作用,对滨海湿地生态系统的维持与健康具有重大影响。系统梳理了滨海湿地土壤微生物群落结构特征和多样性,综述了土壤理化性质、植被状况、水文因素、生物入侵、全球变化、湿地开垦、石油污染等因素对滨海湿地土壤微生物的影响。在此基础上,对今后的研究重点提出了4个方面的展望:(1)加强全球变化多因子交互作用下滨海湿地土壤微生物的响应机制;(2)强化滨海湿地土壤微生物与环境因子的互作机理;(3)深化滨海湿地水动力条件对土壤微生物的影响机制;(4)开展土壤微生物与滨海湿地生态系统物质循环综合研究。研究以期为滨海湿地生态系统的保护和修复提供参考。     

长沙城市斑块湿地资源的时空演变

利用GIS技术,对长沙市1955、1972和1990年地形图湿地数据及2007年长沙市湿地资源普查数据进行提取和分析,选取最具代表性的斑块湿地作为研究对象,从时间与空间、动态与静态、规模与填埋等视角,研究50年来城市斑块湿地生态系统各层次要素的时空演变过程和变化规律.结果表明:(1)时间层次上,长沙城市斑块湿地总面积呈现先增后减、总体增加的态势;斑块湿地面积变化幅度不断加大,速率逐步加快;(2)规模层次上,面积在32 hm2规模以下的斑块湿地呈增加态势,32 hm2规模以上斑块湿地呈减少态势;(3)动态空间层次上,被填埋斑块湿地的比例在建成区和郊区呈相反的演变结果;(4)静态空间层次上,斑块湿地密度在建成区范围和郊区范围演变结果相背.研究显示,伴随着城市化进程,不同时间尺度、不同规模尺度、不同空间属性、不同空间状态的城市斑块湿地常常呈现差异很大、甚至是截然相反的演变结果;无论是动态空间还是静态空间,建成区与郊区的空间分界线往往是城市斑块湿地演变态势的分水岭.     

1973-2013年黄河三角洲湿地景观演变驱动力

1973-2013年间,日益加剧的人类活动和愈发严峻的自然环境对黄河三角洲湿地景观形成巨大威胁。人与自然双重影响下黄河三角洲湿地发生了怎样的变化,哪些因素、多大程度上导致了这种变化的发生,科学解答这些问题对于加强黄河三角洲湿地保护具有重要意义。以Landsat卫星1973-2013年40a的9期影像为数据源,利用人工目视解译方法构建研究区景观数据库,在分析研究区景观特征的基础上,通过主客观相结合的方法,构建了能够反映黄河三角洲地区景观湿地化和人工化状态的表面湿地-人工状态指数(SWCSI)。结合黄河入海水沙、区域降水以及地方生产总值(GDP)、水产品产量和原盐产量,分别从区域尺度和像元尺度上,定量分析了过去40年黄河三角洲湿地景观演变的驱动力及其空间差异。研究表明:(1)过去40年来,黄河三角洲自然湿地面积不断萎缩,人工湿地增加,湿地总面积减小,黄河三角洲整体上呈现出人工化或湿地退化趋势,同时也存在明显的空间异质性:滨海地区以人工化和湿地退化趋势为主,黄河入海口地区以湿地化趋势为主,中西部和西南部传统农耕区基本无变化。(2)黄河三角洲湿地景观的人工化或湿地退化趋势是过去40年来黄河水沙减少、人类活动加剧共同作用的结果。区域尺度上,人类社会经济活动对黄河三角洲湿地景观演变起主导作用,黄河径流量和输沙量的作用明显弱于社会经济因素。像元尺度上,驱动因素的空间异质性是导致黄河三角洲湿地景观演变空间异质性的原因。湿地的发展主要归因于自然因素,以黄河水沙作用最为关键;湿地的人工化或退化过程以人类社会经济活动的强制改造为主导,但是否伴随黄河水沙变化的潜在影响,对特定区域而言应是确定的,但仍很难从像元尺度进行量化。     

Changes of Soil Particle Size Distribution in Tidal Flats in the Yellow River Delta

Background

The tidal flat is one of the important components of coastal wetland systems in the Yellow River Delta (YRD). It can stabilize shorelines and protect coastal biodiversity. The erosion risk in tidal flats in coastal wetlands was seldom been studied. Characterizing changes of soil particle size distribution (PSD) is an important way to quantity soil erosion in tidal flats.

Method/Principal findings

Based on the fractal scale theory and network analysis, we determined the fractal characterizations (singular fractal dimension and multifractal dimension) soil PSD in a successional series of tidal flats in a coastal wetland in the YRD in eastern China. The results showed that the major soil texture was from silt loam to sandy loam. The values of fractal dimensions, ranging from 2.35 to 2.55, decreased from the low tidal flat to the high tidal flat. We also found that the percent of particles with size ranging between 0.4 and 126 μm was related with fractal dimensions. Tide played a great effort on soil PSD than vegetation by increasing soil organic matter (SOM) content and salinity in the coastal wetland in the YRD.

Conclusions/Significance

Tidal flats in coastal wetlands in the YRD, especially low tidal flats, are facing the risk of soil erosion. This study will be essential to provide a firm basis for the coast erosion control and assessment, as well as wetland ecosystem restoration.     

Using ecotechnology to address water quality and wetland habitat loss problems in the Mississippi basin: a hierarchical approach

Human activities are affecting the environment at continental and global scales. An example of this is the Mississippi basin where there has been a large scale loss of wetlands and water quality deterioration over the past century. Wetland and riparian ecosystems have been isolated from rivers and streams. Wetland loss is due both to drainage and reclamation, mainly for agriculture, and to isolation from the river by levees, as in the Mississippi delta. There has been a decline in water quality due to increasing use of fertilizers, enhanced drainage and the loss of wetlands for cleaning water. Water quality has deteriorated throughout the basin and high nitrogen in the Mississippi river is causing a large area of hypoxia in the Gulf of Mexico adjacent to the Mississippi delta. Since the causes of these problems are distributed over the basin, the solution also needs to be distributed over the basin. Ecotechnology and ecological engineering offer the only ecologically sound and cost-effective method of solving these problems. Wetlands to promote nitrogen removal, mainly through denitrification but also through burial and plant uptake, offer a sound ecotechnological solution. At the level of the Mississippi basin, changes in farming practices and use of wetlands for nitrogen assimilation can reduce nitrogen levels in the River. There are additional benefits of restoration of wetland and riverine ecosystems, flood control, reduction in public health threats, and enhanced wildlife and fisheries. At the local drainage basin level, the use of river diversions in the Mississippi delta can address both problems of coastal land loss and water quality deterioration. Nitrate levels in diverted river water are rapidly reduced as water flows through coastal watersheds. At the local level, wetlands are being used to treat municipal wastewater. This is a cost-effective method, which results in improved water quality, enhanced wetland productivity and increased accretion. The problems in the Mississippi basin serves as an example for other watersheds in the Gulf of Mexico. This is especially important in Mexico, where there is a strong need for economical solutions to ecological problems. The Usumacinta delta-Laguna de Terminos regional ecosystem is an example where ecotechnological approaches offer realistic solutions to environmental problems.     

The ecological adaptability of <Emphasis Type="Italic">Phragmites australis</Emphasis> to interactive effects of water level and salt stress in the Yellow River Delta

Soil salinity and waterlogging are two major environmental problems in estuarine wetlands. To prevent the typical wetland plants from degradation by soil salinization and salt waterlogging and more effectively use the plants to provide wetland ecosystem services, we examined the ecological adaptability of Phragmites australis, a characteristic plant species in the Yellow River Delta, to the interactive effects of water level and salt stress. The results showed that P. australis adapts to salt and water table stressed environments through slowing down the growth rate, maintaining the tiller number, and adjusting the biomass allocation of different organs. The highest plant height and the largest leaf area were at 0 cm water table treatment; the 0.5 % NaCl treatment increased the aboveground biomass; higher water table increased the fibrous root biomass allocation, but largely decreased the leaf biomass. The exclusion of toxic inorganic ions such as Na⁺ and Cl^? and the accumulation of organic solutes are also important mechanisms to aid survival in saline wetlands. On average 35.1 % of Cl^? and 53.9 % of Na⁺ accumulated in belowground organs. The study could provide fundamental guidance for wetland restoration projects and wetland sustainable use in coastal zones such as the Yellow River Delta.     

基于CiteSpace的湿地恢复研究进展

由于人类活动、气候变化等影响,全球湿地退化不断加剧,关于湿地恢复的相关研究也越来越多,但缺乏系统的文献梳理,对研究领域的热点演变特征及发展趋势认识不足。基于文献计量学软件CiteSpace.5.5R2及中国知网(CNKI)和Web of Science核心数据库检索的文献数据,对湿地恢复领域的发文量、作者群、发文机构、文献共被引、高频关键词及突现等进行可视化分析。结果表明：(1)国内外关于湿地恢复研究的发文量总体上均呈现增长趋势,2008年之后发文量均显著提升,国内研究较国外晚了近10年,但发展迅速,国际影响力提升较快;(2)国外主要研究机构包括United States Geological Survey、Louisiana State University、University Florida、University Wisconsin等,均为美国机构,形成了以William JM-John WD、Zedler JB、Jos TA Verhoeven-Leon P M Lamers、Jeffrey WM等核心研究团队;国内以中国科学院、北京师范大学、中国林业科学研究院为主,形成了崔保...     

综合模型法评估黄河三角洲湿地景观连通性

景观连通性是区域生态系统功能完整的重要表征。连通性的评估对生态系统管理和保护规划有重要意义。综合常用的景观连通性评估模型,即最小耗费距离模型与电路理论模型,根据生态网络构建的一般范式,采取两种不同阻力面赋值方案,对黄河三角洲的湿地景观连通性进行评估,并对比分析了两种模型的基本原理、工作性能、分析尺度等。结果表明：最小耗费距离模型能够识别最优生态廊道,为景观连通性评估提供基本模式。电路理论则能扩展到潜在生态廊道和关键生态点的量化识别,能确定具有生态功能的“夹点”和障碍区的空间位置。综合两种模型,可以量化评估黄河三角洲湿地景观连通性,空间化三角洲湿地保护恢复的管理目标,即潜在廊道和关键生态节点,为区域生态系统功能评估和管理提供精准的数据支持。     

Use of seasonal freshwater wetlands by fishes in a temperate river floodplain

This study examined the use of freshwater wetland restoration and enhancement projects ( i.e . non-estuarine wetlands subject to seasonal drying) by fish populations. To quantify fish use of freshwater emergent wetlands and assess the effect of wetland enhancement ( i.e . addition of water control structures), two enhanced and two unenhanced emergent wetlands were compared, as well as two oxbow habitats within the Chehalis River floodplain. Eighteen fish species were captured using fyke nets and emigrant traps from January to the beginning of June, with the most abundant being three-spined stickleback Gasterosteus aculeatus and Olympic mudminnow Novumbra hubbsi . Coho salmon Oncorhynchus kisutch was the dominant salmonid at all sites. Enhanced wetlands, with their extended hydroperiods, had significantly higher abundances of yearling coho salmon than unenhanced wetlands. Both enhanced and unenhanced emergent wetlands yielded higher abundances of non-game native fishes than oxbow habitats. Oxbow habitats, however, were dominated by coho salmon. Fish survival in the wetland habitats was dependent on emigration to the river before dissolved oxygen concentrations decreased and wetlands became isolated and stranding occurred. This study suggests that wetland enhancement projects with an outlet to the river channel appear to provide fishes with important temporary habitats if they have the opportunity to leave the wetland as dissolved oxygen levels deteriorate.     

上海市湿地景观格局时空演变与驱动机制的量化研究

基于1980-2018年上海市历史遥感数据,定量研究上海市湿地景观格局变化及其驱动机制。为此,采用Fragstats 4.2.1计算了景观格局指数,并在数据处理系统软件平台使用灰色关联系统分析了湿地景观格局与社会、经济以及自然环境之间的灰色关联度。结果表明：（1）自1980以来,上海市湿地面积持续缩减,尤其水田损失最多。截至到2018年,上海市共损失了21.06×10⁴hm²的湿地,现存湿地面积为38.22×10⁴hm²,其中人工湿地占85%,自然湿地占15%。人工湿地以水田为主,自然湿地以河流湿地为主。水田和河流斑块平均面积总体上呈波动缩小趋势。河流湿地的形状复杂性最高,其总面积在年际间缓慢缩减,平均分形维度指数年际间波动持平。水田平均分形维度指数年际间波动上升,景观形状向复杂化趋势发展。（2）1980-2010年间,湿地景观破碎化程度总体加剧,最大斑块指数呈波动下降趋势。2010年后,景观破碎化局势向好,最大斑块面积扩大。1980-2015年间,蔓延度指数呈波动下降趋势,香农多样性指数呈波动上升趋势。2015年是蔓延度指数和香农多样性指数变化的转折点。水库坑塘斑块形状较简单,年际间变化小,而且具有结构的自相似性。（3）湿地景观格局受自然、人为双重因素影响。城市扩张导致人工湿地面积减少。自然湿地的演变则主要受气温和降雨的影响。自然因素往往在较大的时空尺度上控制着湿地的景观格局变化。但随着经济的迅速发展,在较短的时间尺度上,国家政策等人为因素对景观格局的影响力逐渐增强。未来,国家对城市湿地保护政策的实施可以使湿地景观格局向好的方向演化。     

A review of methodologies and success indicators for coastal wetland restoration

Coastal wetlands are considered to be amongst the most productive ecosystems and can provide invaluable ecological services. However, coastal wetlands are listed amongst the most threatened ecosystems suffering from anthropogenic activities. The loss or degradation of coastal wetlands has drawn a high level of attention to wetland restoration. Improvement of the structure and function of degraded, damaged and destroyed wetlands may be achieved through ecological restoration. Large numbers of restoration projects have been conducted worldwide based on different restoration goals and different methods. It is undoubtedly important to evaluate whether coastal wetland restoration is successful. However, coastal wetland restoration assessment has become challenging because of current disagreement on definitions and concepts of restoration evaluation. We reviewed the methodology of coastal wetland restoration and criteria for success evaluation, and then summarized the issues for current wetland restoration and success evaluation based on literature review. Moreover, we used an estuarine wetland affected by urbanization as a sample to demonstrate how to establish a success indicator system for guiding wetland restoration and evaluating the success of wetland restoration.     

长江黄河源区湿地分布的时空变化及成因

通过整理解译1969年航片、1986年、2000年、2007年以及2013年TM影像数据,对长江黄河源区的高寒湿地分布的时空变化特征进行分析,并结合气象观测数据和人类活动状况,运用主成分分析和灰色关联度法定量分析造成高寒湿地退化的气候因素和人为因素的贡献,并揭示了高寒湿地退化与各环境因子之间的关联性。结果表明:1969年—2013年间,江河源区的高寒湿地面积减少了19.16%,各湿地类型的斑块分离度不断增大;空间上,高寒湿地的退化区主要分布在长江源区的东北部以及黄河源区的北部地区,与该区域冻土的退化有显著的一致性;1969年以来,江河源区的气候呈气温显著上升、相对湿度降低以及降水量微弱增加的暖干化趋势,湿地的退化与气候变化在时间上有明显的同步性,其中气温升高是形成湿地退化格局的主要原因,降水量和相对湿度的变化会对湿地的变化产生重要影响,尤其是对河流和湖泊的影响更为显著;此外,载畜量的变化是影响湿地变化最重要的人为因素。     

不同恢复措施对南滇池湿地冬季水禽多样性的影响

恢复受损湿地生态功能是国家湿地公园建设中的重要内容,修复措施的选用会对恢复效果产生重要影响。滇池是国内重要候鸟越冬区,受长期围垦以及城市扩张的影响,湖滨区域破坏严重,近年来湿地公园建设为滇池湖滨带恢复带来了契机,但各种恢复措施的效果仍有待明确。2017年冬季以昆明南滇池国家湿地公园及临近湿地为研究区域,设置了人工重建湿地、人工恢复湿地、自然恢复湿地以及自然湖泊湿地4个对照样区,基于冬季水禽多样性进行了湿地恢复效果评价,并从景观生态学角度对结果进行了分析。结果表明：自然湖泊湿地具有最高物种丰富度,其次为自然恢复湿地、人工恢复湿地和人工重建湿地。以Simpson多样性指数评价,自然恢复湿地的水禽多样性最高（0.60±0.03）,其次为自然湖泊湿地（0.46±0.04）和人工恢复湿地（0.34±0.04）,人工重建湿地水禽多样性最低（0.17±0.03）,由此可见自然恢复措施效果优于人工恢复和人工重建。从景观格局上分析,水禽多样性与道路面积（r=-0.735,P<0.01）、景观形状指数（r=-0.461,P<0.01）和景观分离度指数（r=-0.661,P<0.01）负相关,这也表明人为干扰程度、景观形状以及破碎化程度均会对水禽造成重要影响。建议在国家湿地公园规划和建设中,降低非湿地类景观尤其是道路对整体湿地景观的分割作用,提高湿地斑块的连接性和完整性以满足水禽的空间需求,对于湖泊型的湿地公园应加强对湖滨带沼泽生境的营造,以满足涉禽的生存需求,从而增加区域的鸟类多样性。     

黄河三角洲重度退化滨海湿地盐地碱蓬的生态修复效果

采用翻地、施肥和芦苇碎屑培肥等土壤改良方法,利用盐地碱蓬在黄河三角洲重度退化区进行生态修复实验研究。结果表明:重度退化湿地土壤改良后,盐地碱蓬能够成功生长,3种改良方法均可有效的降低重度退化盐碱地的土壤含盐量,改良后的土壤Na离子含量均显著低于对照组,土壤脲酶和磷酸酶活性与对照相比有了显著的提高,表明改良后土壤肥力得到了改善。3种改良方法比较,培肥处理组土壤Na离子含量显著低于其他两种方法;盐地碱蓬生物量达到最高值,说明增加有机物的培肥方法可有效的改良重度退化盐碱湿地土壤,达到较为理想的生态修复预期效果。