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全球范围内有植被定植的海岸带栖息地(红树林、盐沼和海草床)是巨大的沉积物有机碳碳库，同时也是自然生态系统中最密集的碳汇之一，在全球碳循环中发挥着重要作用。针对江苏盐城海岸盐沼湿地沉积物有机碳的研究，区域上的稀疏性和偏向性限制了其作为区域碳汇能力的可靠估计。本研究采用47个100 cm深沉积柱样的现场调查数据，探讨了江苏盐城海岸盐沼湿地沉积物有机碳含量、密度和储量特征。结果表明，0～100 cm深度沉积物有机碳平均含量和平均密度分别为1.68%和23.07 kg/m3，不同盐沼群落沉积物有机碳含量和密度存在一定的差异，其中有机碳平均含量大小排序依次为互花米草>芦苇>盐地碱蓬，有机碳密度排序为芦苇>互花米草>盐地碱蓬。总体而言，3种盐沼群落沉积物有机碳含量的垂向变化趋势与有机碳密度变化趋势具有一致性，芦苇和互花米草表聚性明显。沉积物有机碳含量与其理化性质有关，互花米草群落沉积物有机碳含量具有明显的粒度控制效应，而其他群落不显著。3种盐沼湿地类型0～100 cm深度沉积物总碳储量约为6195.27×103Mg C。研究成果揭... 相似文献
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文章依据2021年9月黄河口盐沼湿地沉积物调查数据，分析了沉积物粒度、容重、有机碳分布特征，并对黄河口盐沼湿地沉积物碳密度及碳储量进行评估。结果显示，黄河口盐沼湿地沉积物类型以粉砂为主，部分层次为砂质粉砂和黏土质粉砂；4种植被类型中，不同深度的沉积物容重差异性不大，互花米草和盐地碱蓬分布区容重整体大于柽柳和芦苇分布区；互花米草、盐地碱蓬、芦苇和柽柳分布区沉积物中有机碳含量分别为0.199%、0.200%、0.184%和0.161%,互花米草和盐地碱蓬分布区底质中有机碳含量较芦苇和柽柳分布区偏高，这与互花米草和盐地碱蓬分布区含有更多的黏土组分有关；计算得出，黄河口盐沼湿地沉积物总碳储量为33.47万t,其中互花米草分布区为14.31万t,芦苇分布区为12.05万t,柽柳分布区为5.27万t,盐地碱蓬分布区为1.84万t。 相似文献
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基于GF-1 WFV影像的黄河口湿地植被盖度估测及分析 总被引：2，自引：0，他引：2
植被盖度是植被生长状况的重要定量指标，而目前开展的植被盖度遥感估测工作主要集中在陆地区域，对河口湿地植被盖度遥感估测工作比较少见。本文基于国产GF-1 WFV遥感影像开展了黄河口湿地植被盖度估算，并结合植被类型、土壤盐度和植被指数分布状况开展了植被盖度分布特征分析，得到如下结论:（1）基于GF-1 WFV卫星影像的NDVI、SRI、SAVI、MSAVI和DVI 5种植被指数，分别建立植被盖度估测模型，其中基于NDVI、SRI、MSAVI和DVI 4种植被指数建立的多变量线性回归模型估测精度最好，其决定系数（R2）最大，为0.904，均方根误差RMSE最小，为0.14；（2）植被盖度估算模型的精度与植被盖度本身有一定的关系，其中各植被盖度回归模型中，盖度大于0.8时估算精度要优于盖度小于0.6的区域，RMSE最大相差0.04；（3）以潮滩碱蓬和潮滩芦苇为主的植被覆盖区属于低植被盖度区，盖度位于0.03~0.5，盐度在1.5 g/L左右；芦苇草甸、互花米草和柽柳灌丛植被覆盖区属于高植被盖度区，盖度位于0.8~1.0，其中芦苇草甸土壤盐度小于1.2 g/L，柽柳灌丛土壤盐度在1.4~2.0 g/L，在高盖度植被区混生有中等盖度的植被，盖度在0.5~0.8，土壤盐度在1.8 g/L左右。 相似文献
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以杭州湾南岸为例，探讨互花米草（Spartina alterniflora）潮滩底质的粒度及其分布特征。结果表明杭州湾南岸互花米草潮滩底质由黏土质粉砂、粉砂、粉砂质砂和砂质粉砂组成；从杭州湾口向湾内，互花米草潮滩底质中值粒径逐渐变粗，分选性变好；从低潮滩向高潮滩，互花米草潮滩底质的中值粒径逐渐变小，分选性变差。互花米草盐沼的形成使得潮滩底质粒度及其分布特征产生明显改变。 相似文献
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江苏海岸带盐沼潮滩在小尺度下的沉积变化过程 总被引：1，自引：0，他引：1
在小尺度范围内,潮滩沉积的研究一般都是基于几个站位或断面进行短时日的调查和监测来获取数据,或多或少地存在数据的连续性不足等问题。基于此,本文在潮滩地貌典型的江苏平原海岸选取了约160 000 m2的盐沼潮滩作为研究对象,在多年的野外连续观测下,分析了人类围垦活动对盐沼潮滩沉积过程及变化的影响。结果表明：人类围垦活动（如堤坝建设等）对潮滩沉积和盐沼植被覆盖的变化有重要影响。围垦堤坝修建之前,研究区向陆一侧为盐沼植物（现为养殖池）,向海一侧为光滩,岸线形态比较平直。在2006年围垦堤坝修建后,研究区变为“凹岸”型的人工岸线,沉积环境变得更有利于泥沙的淤积。根据2007-2012年对滩面高程的野外观测,在风暴潮的影响下,潮滩最大淤积率高达23 cm/a。盐沼植被在泥沙快速淤积的基础上不断发育生长,盐沼植物覆盖面积不断扩张。同时外部的沙嘴也在不断增长,潮汐风浪侵蚀携带沙嘴外部泥沙进入盐沼滩地,盐沼植物在泥沙的覆盖下,出现萎缩退化,覆盖面积减少,但是对潮滩上的泥沙而言还是不断堆积增厚。柱状样岩芯的粒度垂向剖面特征也记录了盐沼潮滩沉积环境的变化。小尺度下盐沼潮滩沉积表现出的阶段性变化规律,揭示出合理的围垦活动有利于堤坝前的潮滩淤积和盐沼植被的扩张。 相似文献
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互花米草作为黄河三角洲外来入侵物种, 2010年开始爆发式蔓延, 2020年面积最大时可超6 000 hm2,对潮间带生物多样性造成了严重影响。自2020年起,黄河三角洲自然保护区开始大规模的互花米草整治与盐地碱蓬生态修复工作。互花米草具有较强的消浪、缓流、促淤、固滩能力,短期内、大范围的植被去除,可能导致波流和沉积动力环境的突变。基于现场观测数据和考虑植被作用的浪、流、沙耦合数值模型,研究分析了互花米草整治和盐地碱蓬修复对黄河三角洲湿地动力过程的影响,重点关注风暴作用下黄河三角洲潮滩湿地的防灾减灾能力和沉积效应变化。研究结果表明,互花米草可有效抵御极端风暴潮,最大风暴潮位衰减率可达15 cm/km。互花米草整治将导致湿地防灾减灾能力显著下降,堤前风暴潮峰值可抬升10～30 cm,同时潮间带的泥沙捕集能力大幅下降。受限于植被密度、高度,盐地碱蓬完全修复后湿地衰减风暴潮、捕集泥沙的能力显著低于原互花米草湿地。研究建议,互花米草整治工程应考虑短期内植被去除导致的近岸风暴潮抬升、侵蚀加剧等潜在风险。 相似文献
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不同的水动力条件及种源高程会影响盐沼植物定植初期的种子扩散活动，导致盐沼不同的扩张格局，进而影响其对潮滩防护工程补充保护的作用。以崇明东滩优势先锋种——海三棱藨草(Scirpus mariqueter)作为研究对象，基于无网格数值模拟方法，研究不同波高(0.01 m~0.11 m)、水深 (0.3 m~2.5 m)、种源所处高程(1.3 m~3.1 m)等条件对定植初期种子扩散活动的影响。结果表明：种子在海陆方向和沿岸方向上的扩散距离与波高呈高度正相关，且当波致切应力达到一定值时，种子在两方向上均存在扩散距离突变现象；种子在海陆方向和沿岸方向上的扩散距离与水深呈显著负相关，且随水深增大种源扩散前端位置离岸距离减小；此外，种子在海陆方向和沿岸方向上扩散距离与种子所处高程均呈负相关。研究结果解释了盐沼植物种子扩散活动的机制，从而为以种子为生态修复材料，以“机会窗口”为概念的生态修复工程提供科学解释。 相似文献
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绿色海堤是传统结构工程与海岸生态系统共同组合而成的新型海堤, 用以应对未来海面上升、风暴加剧给低地海岸防护带来的挑战。需解决的问题主要有海岸生态系统消浪过程及生态系统在海堤体系中的配置方式。理论分析、现场观测、物模数模所获结果表明, 海岸生态系统确有显著的消浪功能: 1) 陆架泥区消浪, 其机制以再悬浮和浮泥运动为主, 底部摩擦为次; 2) 潮滩下部的粉砂细砂滩底部摩擦和推移质运动共同造成波能耗散, 而上部的泥滩则以再悬浮和悬沙输运为主; 3) 在盐沼、红树林、海草床等由植被构成的生态系统, 植物通过形态阻力、茎秆运动来阻滞水流、耗散波能, 其效能高于沉积物床面对波能的耗散; 4) 生物礁主要有珊瑚礁和牡蛎礁, 其消能作用主要通过床面摩擦和波浪破碎, 效能较高, 尤其是在风暴期间。生态系统如何成为海堤的有机组成部分, 尤其是侵蚀型海岸的生态位修复和绿色海堤整体设计, 还需进一步研究相关的科学问题: 与硬质工程结合的盐沼-牡蛎礁的适应性生物学; 未来环境变化条件下生态系统的稳定性; 绿色海堤生态系统空间配置及其与风暴事件的时间尺度匹配; 基于均衡剖面理论的海堤形态优化。 相似文献
9.
互花米草对泉州湾盐沼表层沉积物输运的影响 总被引：1，自引：0，他引：1
海岸盐沼是海岸湿地系统的重要组成部分，具有很强的环境调节功能．互花米草（Spartina alterniflora）的引种对海岸盐沼的沉积动力产生很大影响．粒度分析结果表明，互花米草盐沼边缘与沉积物平均粒径为6．7φ的等值线分布一致．现场观测表明，互花米草对流速具有明显的阻滞作用，使得光滩流速明显大于互花米草内的流速；在互花米草滩内，随着离盐沼边缘距离、植被高度、植株直径的不同，涨落潮流速也表现出不同的变化趋势．粒径趋势分析结果显示，互花米草盐沼边缘的表层沉积物由光滩向盐沼内输运，潮水沟的存在对沉积物的输运格局具有显著影响．对比分析表明落潮后期的水动力条件控制着研究区内表层沉积物的净输运方向． 相似文献
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11.
为探讨盐度对碱蓬生理指标和反射光谱的响应,以滨海湿地盐地碱蓬(Suaedasalsa)为研究对象,采用自然光照盆栽试验方法研究8种盐度(0(对照,CK)、5、10、15、20、25、30和35)对碱蓬幼苗的生理指标(株高、鲜质量、干质量、叶绿素含量、可溶性总糖和蛋白质质量比)和反射光谱的响应。研究结果表明:盐度对碱蓬植株生理指标存在显著响应,低中盐度(0～25)对植株生长有促进作用,而高盐度(30～35)对植株生长起到抑制作用;25盐度下,碱蓬株高、鲜质量、干质量、叶片叶绿素含量、可溶性总糖质量比均高于其他盐度和对照组;不同盐度处理下的碱蓬植株蛋白质质量比均高于对照组;盐度对碱蓬反射光谱存在明显响应,碱蓬在绿光和近红外波段的反射率随着盐度的增加而逐渐减小;通过相关分析判断出碱蓬株高、鲜质量、干质量、叶绿素含量、可溶性总糖和蛋白质质量比的诊断波段,分别是547、555、548、556、546和2 300 nm。碱蓬高光谱特征指数MTCI、MNDVI1、DCNI、TCARI/OSAVI和R546在不同盐度下存在明显差异,可作为盐分胁迫的高光谱响应诊断指标。分析盐度对碱蓬生理指标和反射光谱的响应,可为深入研究碱蓬对退化滨海湿地生态修复具有重要参考意义。 相似文献
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联合国环境署(1990)在题为“海相环境的状况”的报告中指出,世界人口约一半集中在海岸地区,因而这些地区人口压力巨大,同时受到污染、风暴潮、地面沉降的威胁,以及高地灌溉水资源枯竭的影响;在低地海岸、河滩和湿地,海平面的上升将会给沿岸城市的工农业生产及人民生活带来极其严重的后果。而盐沼-潮沟体系则是淤泥质海岸缓冲、削减波浪-潮流能量的重要地貌系统,对海岸的保护起着至关重要的作用。潮沟常常贯穿盐沼与泥坪(或沙坪),成为沟通盐沼-泥坪体系物质能量交换的纽带;在淤涨型淤泥质海岸上,细颗粒泥沙被涨潮流沿潮沟输送到盐沼上,结果使盐沼不断向海淤进。而当海平面上升时,盐沼-潮沟系统功能又发生改变,成为削减潮汐能量的“装置”。Pethick(1980,1992)研究了英国Norfolk盐沼潮沟水流的特征,并提出了流速的预报模型;Healey等(1981)在观测中发现了一些与模型不符的情况。本文从地貌和动力方面研究了江苏淤泥质海岸弶港盐沼风车河潮沟的地貌演变与动力演化的关系,以及水动力与地貌因素之间的相互响应机制。 相似文献
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TANG Yijie FANG Zhanqiang CHEN Kang ZHANG Zaiwang ZHONG Yanting AN Dong YANG Xiongbang LIAO Baowen 《海洋学报(英文版)》2012,31(5):115-125
The study aims to compare the differences of macrofauna communities of wetlands at 3-year-forest- age, 5-year-forest-age Sonneratia apetala artificial mangroves, 5-year-forest-age Kandelia candel ar- tificial mangroves with the same restoration background, and the naked tidal flat in the Qi’ao Island Mangrove Nature Reserve of Zhuhai, Guangdong Province. The results show that there were signif- icant structural differences in macrofauna communities among four kinds of habitats. The increase of biomass and species diversity of macrofauna at 3-year-forest-age S. apetala artificial mangroves was obviously faster than that at 5-year-forest-age K. candel artificial mangroves whose average tree height was close to that of 3-year-forest-age S. apetala artificial mangroves. The BIOENV analysis shows that it was related to the rapid growth of S. apetala, which rapidly changed the light level and shading conditions in the forests. The 5-year-forest-age S. apetala artificial mangroves had lower macrofauna species diversity but higher density and biomass than K. candel artificial mangroves with the same forest age. This was due to the rapid changes of physical and chemical properties of habitat soil by the ecological restoration of S. apetala artificial mangroves as well as the changed food sources possibly caused by the leaf-litter of such non-indigenous mangrove species S. apetala. However, further survey should be conducted on whether there are any negative ecological impacts of large-scale cultivation of S. apetala on macrofauna communities, so as to evaluate correctly S. apetala’s role in the restoration of coastal mangrove ecosystems. 相似文献
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基于卫星遥感的潮滩植被、高程、潮沟空间关系探讨-以崇明东滩为例 总被引：3，自引：1，他引：2
The analysis of vegetation-environment relationships has always been a study hotspot in ecology. A number of biotic, hydrologic and edaphic factors have great influence on the distribution of macrophytes within salt marsh.Since the exotic species Spartina alterniflora(S. alterniflora) was introduced in 1995, a rapid expansion has occurred at Chongming Dongtan Nature Reserve(CDNR) in the Changjiang(Yangtze) River Estuary, China.Several important vegetation-environment factors including soil elevation, tidal channels density(TCD),vegetation classification and fractional vegetation cover(FVC) were extracted by remote sensing method combined with field measurement. To ignore the details in interaction between biological and physical process,the relationship between them was discussed at a large scale of the whole saltmarsh. The results showed that Scirpus mariqueter(S. mariqueter) can endure the greatest elevation variance with 0.33 m throughout the marsh in CDNR. But it is dominant in the area less than 2.5 m with the occurrence frequency reaching 98%. S. alterniflora has usually been found on the most elevated soils higher than 3.5 m but has a narrow spatial distribution. The rapid decrease of S. mariqueter can be explained by stronger competitive capacity of S. alterniflora on the high tidal flat. FVC increases with elevation which shows significant correlation with elevation(r=0.30, p0.001). But the frequency distribution of FVC indicates that vegetation is not well developed on both elevated banks near tidal channels from the whole scale mainly due to tidal channel lateral swing and human activities. The significant negative correlation(r=–0.20, p0.001) was found between FVC and TCD, which shows vegetation is restricted to grow in higher TCD area corresponding to lower elevation mainly occupied by S. mariqueter communities. The maximum occurrence frequency of this species reaches to 97% at the salt marsh with TCD more than 8 m/m2. 相似文献
15.
Since the 1980s, the coastal wetlands in Korea have been rapidly degraded and destroyed mainly due to reclamation and landfills
for coastal development. In order to recover damaged coastal environments and to develop wetland restoration technologies,
a 4-year study on ecological the restoration of coastal vegetated ecosystems was started in 1998. As one of a series of studies,
a small-scale experiment on salt marsh restoration was carried out from April 2000 to August 2001. The experiment was designed
to find effective means of ecological restoration through a comparison of the changes in environmental components and species
structure between two different experimental plots created using sediment fences, one with and one without small canals. Temporal
variation in surface elevation, sedimentary facies, and benthic species were measured seasonally in each plot and in the adjacent
natural reference sites. Monthly exposure occurred from 330 cm to mean sea level, which represents the critical tidal level
(CTL) at which salt marsh plants colonize. Vegetation, especially Suaeda japonica, colonized the site the following spring and recovered to a similar extent in the natural marshes 16 months later. The sedimentary
results indicated that the sediment fences had effects on particle size and sediment accumulation, especially in the plot
with small canals. This experiment also showed that tidal height, especially that exceeding the CTL, is an important factor
in the recovery of the benthic fauna of salt marshes. From these results, we suggested that designs for the restoration of
salt marsh ecosystems must consider the inclusion of a tidal height exceeding CTL, as this may allow reconstruction of the
previous natural ecosystem without artificial transplanting. 相似文献
16.
Graham P. Wilson Angela L. Lamb Melanie J. Leng Silvia Gonzalez David Huddart 《Estuarine, Coastal and Shelf Science》2005,64(4):685-698
Microfossil analysis (e.g. diatoms, foraminifera and pollen) represents the cornerstone of Holocene relative sea-level (RSL) reconstruction because their distribution in the contemporary inter-tidal zone is principally controlled by ground elevation within the tidal frame. A combination of poor microfossil preservation and a limited range in the sediment record may severely restrict the accuracy of resulting RSL reconstructions. Organic δ13C and C/N analysis of inter-tidal sediments have shown some potential as coastal palaeoenvironmental proxies. Here we assess their viability for reconstructing RSL change by examining patterns of organic δ13C and C/N values in a modern estuarine environment. δ13C and C/N analysis of bulk organic inter-tidal sediments and vegetation, as well as suspended and bedload organic sediments of the Mersey Estuary, U.K., demonstrate that the two main sources of organic carbon to surface saltmarsh sediments (terrestrial vegetation and tidal-derived particulate organic matter) have distinctive δ13C and C/N signatures. The resulting relationship between ground elevation within the tidal frame and surface sediment δ13C and C/N is unaffected by decompositional changes. The potential of this technique for RSL reconstruction is demonstrated by the analysis of part of an early Holocene sediment core from the Mersey Estuary. Organic δ13C and C/N analysis is less time consuming than microfossil analysis and is likely to provide continuous records of RSL change. 相似文献
17.
18.
米草属植物Spartina angilica和Spartina alterniflora引种后江苏海岸湿地生态演化的初步探讨 总被引：14，自引：2，他引：14
选取江苏王港潮滩的盐蒿滩、大米草滩及互花米草滩,分析这三类滩面的地面以上生物量、初级生产力、动物洞穴参数和沉积物粒度,探讨大米草和互花米草引种区的湿地生态系统相对于盐蒿滩的变化.分析结果表明,互花米草滩的生物量远大于盐蒿滩和大米草滩;单位面积上动物洞穴数量相近,但洞穴大小有一定差异,互花米草滩动物洞穴稍大,数量也相对较多,这可能与初级生产力的提高有关.表层底质的粒径以互花米草滩为最细,盐蒿滩最粗,这种分布状况与互花米草引种前不同,说明互花米草促进了细颗粒物质的堆积.互花米草的引种在江苏海岸具有促淤和提高初级生产力的作用,而它对湿地生态系统的结构和功能的影响需要进一步研究. 相似文献