【作者】 安传光；

【导师】 赵云龙；

【作者基本信息】 华东师范大学 ， 动物学， 2011， 博士

【摘要】 长江河口湿地是全球50个对环境变化敏感的区域之一。大型底栖动物在河口生态系统营养关系中占据着承上启下的关键位置,其多样性与分布格局的改变会引起初级生产者以及高级消费者相应的种群及群落的变化。此外,大型底栖动物还调节着河口生态系统的许多生态功能,其群落结构的改变影响河口沉积物稳定性及物质输送等重要的物理、化学和地质过程。因此研究大型底栖动物的群落特征、分布格局,不仅有助于了解底栖动物类群对潮间带的作用,而且可为了解河口潮间带生态系统功能以及其它生物对河口潮间带的利用提供基础资料。大型底栖动物群落特征是河口生态学的基础,但至今长江口潮间带大型底栖动物尚缺少全面系统的研究。同时,近年来长江口受人类活动干扰频繁,迫切需要了解长江口湿地生态系统的底栖动物群落特征,以应对河口受损湿地、生态修复提供基础资料。因此,本文从陆缘潮间带和岛屿潮间带较为全面地分析了大型底栖动物的群落特征,并探讨了潮间带湿地修复过程中大型底栖动物的演替规律等。主要研究结果如下：1.长江口大型底栖动物群落特征本次调查的地域范围基本涵盖了长江口主要的陆缘和岛屿的潮间带。包括崇明岛、北港北沙、九段沙及南汇陆缘滩涂四部分。2006年6月和10月对崇明岛潮间带进行了大型底栖动物调查,设置了21个采样断面,采集到大型底栖动物72种,隶属于5门、41科。6月的密度和生物量分别为166.20ind/m2和99.28g/m2,10月的密度和生物量分别为136.81ind/m2和83.04g/m2,多样性指数H’、J和D的值分别为1.851±0.528、0.306±0.098和0.622±0.141。优势种有无齿相手蟹(Sesarma dehaani)、天津厚蟹(Helice tientsinensis)、谭氏泥蟹(Ilyrplax deschampsi)、河蚬(Corbicula fluminea)、中国绿螂(Glauconome chinensis)、绯拟沼螺(Assiminea latericea)、拟沼螺(Assiminea sp、尖锥拟蟹守螺(Cerithidea largillierli)等。近年来崇明岛围垦较少,潮间带的高程较高,因此,生活在崇明岛的潮间带上部的半陆生蟹类繁盛,对生物量贡献大,如无齿相手蟹分别占6月和10月总生物量的32.35%和43.64%。经聚类分析,崇明岛潮间带的底栖动物可以分为南部群落、东滩群落和北部群落,这与三个群落差的盐度、沉积物和植被差异较大有关。南部群落底栖动物群落种类组成简单,半陆生的无齿相手蟹为优势种；北部群落的种类组成较复杂,该区域的盐度高、沉积物颗粒细,泥螺(Bullacta exarata)和彩虹明樱蛤(Moerella iridescens)是部分断面低潮带的优势种；东滩是盐度变化最剧烈的区域,沉积物颗粒较粗,大型底栖动物种类较多、群落结构复杂。2007年5月、6月和7月对北港北沙潮间带进行了大型底栖动物调查,共设置8个采样断面。北港北沙的高程低,仅在大潮时露出水面,无高等植物分布。由于缺少底栖动物栖息和繁育的场所,大型底栖动物尚处于演替的初级阶段,种类组成简单,有14种,隶属于4门4纲12科。其密度、生物量平均值仅为0.25ind/m2和0.22g/m2,H’J、D和AMBI的平均值总平均值分别为0.667、0.667、0.255和1.122。北港北沙的沉积物不稳定,不适宜双壳纲动物繁殖,也不适合腹足纲动物生存,因此缺少腹足纲动物,并缺少双壳纲仔体。这也说明盐沼植物对维持大型底栖动物多样性有重要意义。2009年5月、7月、10月和12月对九段沙潮间带进行了大型底栖动物调查,共设置8个采样断面。九段沙是处于自然演替中的沙洲,也是上海惟一未被围垦和开发的沙洲。底栖动物种类组成复杂,有82种,隶属于5门49科。全年平均密度和生物量分别为405.80 ind/m2和87.70g/m2。虽然丰水季节九段沙的盐度相对较低,但它受外海海水入侵的几率很高。分布有很多对低盐环境适应能力极强的海水种。如在九段沙东滩出现高密度的四角蛤蜊(Mactra veneyformis)群落,并且有紫彩血蛤(Nuttalia obscurata)和文蛤(Meretrix petechialis)的分布。九段沙潮间带底栖动物密度主要受制于拟沼螺、微小螺(Elachisina sp.)、钩虾(Eohaustorius cheliferus)和中国绿螂的影响；生物量主要受制于无齿相手蟹、缢蛏(Sinonovacula constricta)、焦河篮蛤(Potamocorbula ustulata)和四角蛤蜊(Mactra veneyformis)的影响。江亚南沙潮间带首次发现密度极高的短腿水叶甲(Donacia frontalis)分布。2006年9月和2007年5月对陆缘滩涂进行了大型底栖动物调查,共设置31个采样断面。陆缘滩涂是受人类活动干扰最多的区域,围垦和污染对其产生了重大影响。在大多数区域,陆缘滩涂的高中潮滩几乎丧失殆尽,仅有少量自然滩涂被留存下来。大型底栖动物有67种,隶属于4门36科。春、秋季陆缘滩涂大型底栖动物的密度和生物量分别为：712.81 ind/m2和123.44 g/m2,761.65 ind/m2和115.63 g/m2。高等植物分布区是底栖动物数量、生物量和多样性最高的区域,而陆缘滩涂的高等植物分布带宽度往往只有几十米。围垦使高中潮滩湿地的丧失,使大量在潮间带上部生存的物种栖息地丧失,影响较大的有相手蟹和厚蟹等半陆生种类。人工设施的大量存在,导致硬相潮间带生物的繁盛。此区域底栖动物优势种主要有中间拟滨螺(Littorinopsis intermedia)、齿纹蜒螺(Nerita yoldi)、牡蛎(Crassostrea sp.)和白脊藤壶(Balanus uliginousus)。底栖动物的组成结构的变化,对生态影响尚需要进一步探讨。总而言之,长江口潮间带大型底栖动物的分布规律与高程、盐度、植被、沉积物组成成分密切相关。崇明岛、陆缘滩涂、九段沙的高程、盐度较高、植物群落完整,大型底栖动物的物种数、密度、生物量和多样性指数较高；北港北沙高程低、无高等植物、盐度较低、沉积物颗粒粗,因此北港北沙的相关指标都显著低于其他调查区域。2.人类活动与大型底栖动物群落分布特征的关系本次调查在长江口潮间带设置了68个断面,在2006年6月至2009年12月期间对每个断面进行了2至4次调查取样。共鉴定出大型底栖动物110种,隶属于6门75科。节肢动物最多,有35科63种；软体动物次之,有27科39种；环节动物再次之,有10科18种。节肢动物门、软体动物门和环节动物门的大型底栖动物种类繁多,腔肠动物门、纽形动物门和星虫动物门都仅有一种。按栖息环境的底质特征,软相潮间带类型有65科91种,硬相潮间带类型有7科16种。以往历史资料记录的大型底栖动物都在60种左右,与之相比本文的研究结果丰富了大型底栖动物的物种资料。有些种类在长江口属新分布种,也有些记录种未能采集到标本。中国耳螺(Ellobium chinensis)、紫游螺(Neritina violacea)、紫彩血蛤等均首次在长江口潮间带发现。大型底栖动物种类的增加主要是调查范围扩大的结果。本研究选取在长江口潮滩分布最广泛的无齿相手蟹来分析潮间带大型底栖动物的生物残毒。结果表明：无齿相手蟹对铜等生命活动所需的金属的富集能力很强,对非必须的铅、汞、铬、砷的富集能力弱。崇明岛无齿相手蟹的油类、铜、DDT、铅、镉、砷和铬在部分站位超标,显示出这些区域污染较重,附近水体污染导致了的有毒物质积累。陆缘滩涂的无齿相手蟹的砷、镉、铅和石油类含量偏高,杭州湾沿岸的部分断面铅、镉超标,毗邻排污口是造成超标的主要原因。与历史资料相比,崇明东滩的无齿相手蟹体内的铅、锌、铜残留量均有所增加,但南汇样品的重金属铜、铅残留量有所减少。本文以南汇围垦潮间带为研究对象,用时空替代的方法对南汇围垦区域内的底栖动物进行了跟踪调查。围垦对底栖动物的种类组成、分布、优势种、多样性指数等造成了长期的负面影响。围垦区内大型底栖动物群落迅速衰退,并在有水源的区域演替为湖泊常见的摇蚊群落；围垦区外,大型底栖动物集中分布于几十米宽的促淤堤内,水下建筑区聚集了泥沙质潮间带所没有的类群,如齿纹蜒螺等。长江口外来物种互花米草的扩散,改变了长江口滩涂植被、底栖动物的分布,以及种群数量等,影响到长江口崇明岛和九段沙保护区的生态功能的发挥。控制和减少互花米草势在必行。本研究对互花米草进行割除并用水淹的办法控制互花米草群落,试图恢复芦苇群落。在植被的恢复过程中,大型底栖动物群落也随之发生演替。结果显示,水淹没后的高潮带,底栖动物的种类组成简单化。半陆生或两栖生活的底栖动物将大量减少、甚至绝灭,生活在水体底部的摇蚊幼虫、河蜾赢蜚等繁盛。因此,根据实地调查结果,建议在芦苇植被恢复过程中,应局部保留高潮带区域,以便有足够的空间和底栖动物种质资源迅速恢复修复湿地内的底栖动物群落。总之,从大型底栖动物角度,可以了解九段沙潮间带底栖动物保存较为完好,九段沙潮间带是维护长江口湿地生态系统功能较好的区域之一,陆缘潮间带是开发程度最高的区域,人为的因素对潮间带底栖动物的影响极为严重,作为新生沙洲的北港北沙处于演替的早期阶段。同时崇明岛潮间带和陆缘潮间带受环境污染和围垦的影响,湿地底栖动物的恢复需要的时间周期较长。更多还原

【Abstract】 The wetland of the Yangtze estuary is one of the fifty most sensitive areas to the global climate change. The macrobenthic communities are important dynamic center in the wetland ecosystem of the estuary tidal zone. The changes of macrobenthic communities biodiversity and spatial distribution often influent primary producer and consumer populations. In addition, macrobenthic communities regulate ecological functions of estuary ecosystem. For example, the population fluctuations of the marobentic communities influences many important physical, chemical and geologic processes, such as the stability of sediments and transfer. In order to fully understand the functions of macrobenthic communities to wetland ecosystem of tidal zone and to understand the utilization of the estuary wetland, the community characters of macrobenthic communities should be extensively studied. In this present study, the distribution of macrobenthic communities and the influent factors in the Yangtze estuary intertidal zone were investigated, including investigation of the macrobenthic community distribution in large scale, the environmental factors and residual toxicity in this area. The major conclusions of this research are listed as below:1. Macrobenthic community distribution chracter in the intertidal zone of the Yangtze estuary.This survey covers the main the pericontinental and islands intertidal zone of the Yangtze estuary, including Chongming Island, the main pericontinental zone of Shanghai City, Jiuduansha shoals and Beigangbei shoals.From June to October in 2006,21 sections were set for investigation of macrobenthic fauna in intertidal zone of Chongming Island. In this investigation, totally 72 species were collected, which belong to 41 families of 5 phyla. The density and biomass were 166.20ind/m2 and 99.28g/m2 in June,136.81ind/m2 and 83.04g/m2 in October. The biodiversity values of H’, J and D were 1.851±0.528,0.306±0.098 and 0.622±0.141. The dominant species were Sesarma dehaan, Helice tientsinensis, Ilyrplax deschampsi, Corbicula fluminea, Glauconome chinensis, Assiminea latericea, Assiminea sp., Cerithidea largillierli et. al.. The altitude of intertidal zone is relatively high due to having not dike in Chongming Island for more then ten years. The hemi-terrestrial crabs in the upper intertidal zone were prosperous, which lead to the increasing total biomass in most sections. The biomass of Sesarma dehaan took 32.35% or 43.64% of total biomass respectively in June and October. According to the cluster analysis results, the macrobenthic communities could be divided to three groups, communities in south of Chongming Island, Chongming Dongtan wetland communities and communities in north of Chongming Island.The three areas are different in the salt, sediment and plants. In the south of Chongming Island, the species compositions of macrobenthic communities were simple. The biomass of Sesarma dehaani took more than half of total biomass. In the north of the isoland, the macrobenthic communities showed complicated compostions due to the brackish and fine sediments. Bullacta exarata and Moerella iridescens dominated the low mudflat. In the Chongming Dongtan region, due to fluctuated salt and coarse sediments, the macrobenthic species were also abundant.From May to July of 2007,8 sections were set in every month for investigation of macrobenthic fauna of Beigangbei shoals. The altitude of Beigangbeisha shoal is very low. It is higher than water only during spring tides. No vascular plant was distributed yet. Since lacking living and breeding area, the macrobenthic communities showed simple composition. Only 14 species were founded in the present study. The density was 0.25ind/m2, the biomass was 0.22g/m2, and the average biodiversity values of H’, J, D and AMBI were 0.667, 0.667,0.255 and 1.122, respectively. The unstable sediment is not suitable for bivalves breeding, nor for survive of gastropoda. These data suggest that plant is extremely important to maintain macro benthic community diversity.In May, July, October and December of 2009,8 sections were set for macro benthic communities research in Jiuduansha shoals. The Jiuduansha shoal was the only island that has not been dike and utilized by human in the Yangtze estuary. It is reserved for migratory birds. The macrobenthic community composition was complex.82 species were collected, which belong to 49 families of 5 phyla. The density and biomass were 405.80ind/m2 and 87.70g/m2 respectively. In Jiuduansha shoal, vascular plants are widely distributed and macro benthic communities show complicated compositions. Salty varied seasonally. The abundance and biomass were lower in October 2009 than in other months, the migratory birds may prey too many macrobenthos. For example, Mactra veneyformis was abundance in east Jiuduansha, Nuttalia obscurata and Meretrix petechialis were found. The density was mainly controlled by Assiminea sp., Elachisina sp., Eohaustorius cheliferus and Glauconome chinensis; the biomass was controlled by Sesarma dehaani, Sinonovacula constricta, Potamocorbula ustulata, and Mactra veneyformis. In the intertidal zone of Jiangya South shoal, densely distributed Donacia frontalis were observed and it is the first time that this species was found distributed in the Yangtze estuary.From September 2006 to May 2007,31 sections were set in the pericontinental zone of Shanghai for macro benthic communities research. In this investigation, totally 67 species were collected which belong to 36 families of 4 phyla. The density and biomass were 712.81 ind/m2 and 123.44 g/m2 in spring,761.65 ind/m2and 115.63 g/m2 in autumn. The pericontinental intertidal zone was the most artificially influenced area in the present investigation, including dike and pollution. High intertidal zone was almost lost and only very narrow intertidal zone was rested. The vascular plants distributed zone was narrow, in which macro benthic community of the highest species number, biomass and biodiversity should be distributed. The decreasing intertidal zone led to that macrobenthos lose their habits especially in high interdidal zone, such as the hemi-terrestrial crabs. By contrast, macrobenthos species as Littorinopsis intermedia, Nerita yoldi, Crassostrea sp. and Balanus albicostatus are widely distributed.To conclude, the distribution of macrobenthos in the intertidal zone of the Yangtze estuary was related to altitude, salt, plant, contaminants, sediments. The intertidal zones of Chongming Island, the pericontinental zone of Shanghai City and Jiuduansha shoals have relatively higher altitude and salinity, and posses complete plant communities. In these areas, the macrobenthic species number, density, biomass and diversity index values are relatively higher. Whereas, the intertidal zone of Beigangbei shoals have low altitude and salinity, coarse sediments and lack vascular plant. Therefore, the values of macrobenthic communities in the intertidal zone of Beigangbei shoals are significantly lower other regions.2. Human activities and the distribution of macrobenthic communityFrom June of 2006 to December of 2009, totally 68 sections were set for investigation of macrobenthic fauna in intertidal zone of the Yangtze River estuary. Along each section,3 sample sites were set from the high to the low tidal zone and each section was sampled 2-4 times. In this investigation, totally 122 species were collected which belong to 71 families of 6 phyla. Arthropoda were the richest in species number, including 61 species of 32 families. 38 molluscas species were recorded, which belong to 26 families.18 annelid species were found, which belong to 10 families. Among the 122 total species,91 species which belong to 65 families were found distributed in soft-sediment area, as mudflats or sandflats.16 species which belong to 7 families were found only distributed in hard-sediment area. The species records are largely increased in number compared to the around 60 species of the history data. Some species without previous record were acquired in this investigation. Ellobium chinensis, Neritina violacea and Nuttalia obscurata were first record in the Yangtze rive. However some species with previous record were not acquired in this investigation. The species number increasing is mainly due to the increased sampling area in the present study.Residual toxicity in certain macrobenthic species was analysized.The results showed that concentrations of Zn, Cd, Pb and petroleum were highly accumulated in Sesarma dehaani of the Hangzhou Bay. The accumulations of heavy metals, Pb, Cd and As were high also in Chongming Island. Sesarma dehaani accumulated more heavy metals which are essential for life than those are unessential, for an example, the essential Cu and Zn is more accumulated than the unsessential Pb, Hg and As.The value of accumulation in Sesarma dehaani of petroleum, Cu, Pb, Cr, Cd and DDT, was high in Chongming Island. This showed that the pollution is severe in Chongming Island and is dangerous for migratory birds. Previous report showed that the Pb and Cd in Chongming Island and Pb in Jinshan was high in the mud snail. Compared with previous data, the accumulations of Pb, Zn and Cu in Dongtan wetland have been slightly increased. By contrast, the accumulations of Cu and Pb have been slight decreased. The value of residual toxicity display declined trend from Chongming Island, Fengxian, Jinshan, Baoshan to Nanhui.In September of 2004,2006 and 2008,3 sections and 15 sampling sites, totally 75 sample plots, were set up in intertidal zone of Nanhui district of Shanghai for qualitative and quantitative investigation of marobenthos. Ecological quantitative observation approaches were utilized in our present studies to evaluate the effects of diked wetland on macrobenthic communities. As conclusion, dike showed negative effect for macro benthic species, distribution and dominant species in long run. The macro benthic communities degenerate quickly, and Chironomid larve appeared and Chironomid community was even gradually formed in the pools. The concentrated distribution of macrobenthos was in tens of meters wide area between the bank and the groyne. On the underwater constructions lived some macrobenthos which never appeared in the mudflat or sandflat, such as Nerita yoldi.Spartina alterniflora invasion in the Yangtze estuary tidal flat affect ecology functions of Chongming Dongtan and Jiuduansha Island reservation area. Limit and reduce the distribution of Spartina alterniflora are necessary. In this experiment, Spartina alterniflora was removed by submergence. After the remove Spartina alterniflora, Phragmites australis resettled and during the plant recovery, a succession of macrobenthic communities was recruited. The results showed that the macrobenthic communities were simplified after the submergence, since macrobenthos survived only in the intertidal flats. However, Diptera larvae and Corophium sinensis are prosperous.更多还原