【作者】 谢志发；

【导师】 陆健健；

【作者基本信息】 华东师范大学 ， 生态学， 2007， 硕士

【摘要】 本文以长江河口潮滩湿地为例，分析研究外来种互花米草（Spartina alterniflora）盐沼内大型底栖动物群落的特征，结合环境因子，探讨二者的生态学关系，并对长江河口互花米草盐沼的生态系统服务价值进行评估。本研究关注互花米草对河口大型底栖动物群落的影响，调查分析了互花米草引入长江河口潮滩湿地后大型底栖动物群落的种类组成、丰度和多样性变化，探讨互花米草盐沼的正负生态效应。在学术上深入理解了河口生态系统的结构和过程，在应用上为互花米草盐沼湿地的评价、湿地生态建设提供依据。主要研究结论如下：1)互花米草盐沼的大型底栖动物群落的物种丰富度、多样性在长江河口不同生境中处于中间水平。大型底栖动物的种类组成与沉积物粒径、高程和植被特征呈显著相关（P＜0.05）。砂质光滩的大型底栖动物只有3种，丰度和多样性都低于粒径较细的其余生境。在旱柳沼泽，由于高程造成的大型底栖动物群落陆生化，和其他生境存在明显差异。盐沼和淤泥质光滩的底栖动物群落较为相似。本研究进一步证实了沉积物、高程和植被是长江河口潮滩湿地大型底栖动物群落的主要影响因素。同时，互花米草盐沼和芦苇盐沼的大型底栖动物群落种类组成、多样性特征具有较高的相似度（达60％）。2)沿着长江河口纵向梯度，互花米草盐沼的大型底栖动物群落的物种数和多样性从上游到下游呈逐渐增多的趋势，丰度主要受到沉积物粒径和互花米草高度的影响。研究发现，长江河口互花米草盐沼有大型底栖动物21种，主要种类为拟沼螺（Assiminea sp．）、背蚓虫（Notomastus latericeus）、尖锥拟蟹守螺（Cerithidea largillierli）、中国绿螂（Glauconome chinensis）、钩虾（Gammaridae sp．）等。食性功能群均以碎屑食者和植食者为主。大型底栖动物平均丰度为650.5±719.2ind．/m²。北湖的拟沼螺丰度很大，远高于其他样地底栖动物的平均丰度，造成统计结果中的标准差较大。丰度和物种多样性在夏季最高，冬季最低。大型底栖动物平均生物量为20.8±6.1g/m²，季相变化为夏季＞秋季＞春季＞冬季。生物环境匹配（BIO-ENV）分析表明沉积物粒径和盐沼高度是影响互花米草盐沼大型底栖动物群落丰度的主要因素。3)发育时间较长的互花米草盐沼比发育时间短的支持了丰度和多样性更高的大型底栖动物群落。大型底栖动物群落结构和多样性特征与盐沼的发育过程有密切联系。互花米草引入长江河口后，通过与芦苇竞争直接改变生境结构或间接影响水文地质等作用，明显地影响着大型底栖动物群落。互花米草盐沼发育初期，大型底栖动物群落以腹足类为主，丰度和多样性较低，物种丰富度（d=2.18）和多样性（H′=2.19）均低于芦苇盐沼（d=2.61，H′=2.29）。随着时间的推移，互花米草与本地生物逐渐形成互动和稳定的格局，大型底栖动物群落组成中多毛类的种类逐渐上升（由3种变为6种），物种总数和丰度也上升，从而逐步形成新的大型底栖动物群落，物种丰富度（d=2.70）和多样性（H′=2.48）逐渐上升并高于芦苇盐沼（d=2.19，H′=2.09）。但是从大型底栖动物群落的重新形成到稳定阶段，至少需要若干年的时间。4)计算了8类长江河口互花米草盐沼的生态系统服务功能的价值，为每年31757万元，单位面积价值为6.97万元．ha^-1．yr^-1，比长江口湿地的平均水平高出275％。其中促淤造陆和大气调节的价值最高，占到总价值的71％。其余依次为物质生产、消浪保滩、科学文化、营养物质循环、净化环境和生物多样性方面的价值。长江河口互花米草盐沼各项生态系统服务功能的单位面积价值均高于或等于长江口湿地的平均水平，特别是在促淤造陆、消浪保滩和大气调节方面。这表明互花米草可以作为河口地区优良的促淤保滩、调节物质循环的生态工程物种。与杭州湾南岸相比，长江河口地区互花米草盐沼的促淤造陆、物质生产、大气调节三个方面的单位面积价值较高，而环境净化和生物多样性方面则较低。这与两地的经济地理和互花米草的生长状况差异有关。互花米草盐沼在不同地区体现的各项生态系统服务功能具有不同的重要性。对于不同背景下的互花米草盐沼，应该采取不同的生态系统管理策略。综上所述，在长江河口潮滩湿地中，互花米草盐沼内大型底栖动物群落的物种丰富度、多样性处于中间水平，并且沿河口纵向梯度从上游到下游呈逐渐增多的趋势，丰度主要受沉积物粒径和互花米草高度的影响。互花米草盐沼发育初期，其大型底栖动物群落的物种丰度和多样性较低，特别是活动能力强的蟹类较少。但随着时间的推移，逐步形成新的大型底栖动物群落，其丰度和多样性逐渐上升并高于芦苇盐沼。互花米草盐沼具有较高的生态系统服务价值，也具有一定的负生态效应。互花米草生长和繁殖迅速，与本地种形成强烈竞争，从而改变了原有盐沼的生境和生物多样性等，特别是在一些高程较高、适宜贝类养殖的光滩扩展迅速，侵占贝类分布区，减少了一些湿地鸟类的栖息生镜。因此，在对待外来种互花米草时，应该辩证地看待互花米草的正负生态效应。对于不同背景下的互花米草盐沼，应该采取不同的生态系统管理策略。在需要发展滩涂养殖产业、保护水鸟栖息地的地区对互花米草盐沼进行控制，防止其过度扩张；在其他地区可科学发展互花米草盐沼，充分发挥其较高的生态系统服务价值，为人类生活和生产服务。更多还原

【Abstract】 In this paper, we took the tidal flats in the Yangtze Estuary as a case study. The community structure and biodiversity of macrobenthos in the exotic Spartina alterniflora salt marsh were studied. The relationship between environmental factors and macrobenthos were also analyzed. The ecosystem services value of S. alterniflora salt marsh was evaluated in the end.This study concentrated at the influence on estuarine macrobenthos impacted by S. alterniflora salt marsh, investigated the change of species composition, abundance and diversity of macrobenthos after the introduction of S. alterniflora to the Yangtze Estuary. The ecological effects of S. alterniflora salt marsh were analyzed. This study could deepen the study on estuarine ecosystem and process. It also helped to evaluate S. alterniflora, and to supply scientific foundation of applying S. alterniflora for ecological restoration.Major conclusions were as follow:1 The species abundance and diversity of macrobenthos in S. alterniflora salt marsh was at the mean level among different habitats. Species composition of macrobenthos were strongly related to sediment grain size, elevation and vegetation （P<0.05）. Only 3 species were recorded in sand flat while abundance and diversity were lowest among several habitats. Macrobenthos in Salix matsudana zone turned to be terricolous and differed from others because of elevation. Macrobenthos in mud flat was similar with which in salt marsh. The study demonstrated further that macrobenthos in the tidal flat wetlands of Yangtze Estuary were mainly affected by sediment, elevation and vegetation.. Macrobenthos in S. alterniflora and Phragmites australis salt marshes had the highest similarity （60%）.2 Along the environmental gradient, species numbers and diversity of macrobenthos in S. alterniflora salt marsh presented a trend of increasing gradually from the upper to the lower region of the Yangtze Estuary. 21 species were identified. Assiminea sp., Notomastus latericeus, Cerithidea largillierl, Glauconome chinensi, Gammaridae sp. were the dominant species. Functional groups were mostly composed ofdetritivorous group and phytohagous group. The average density of all macrobenthos was 650.5±719.2ind./m². High value of standard deviation of density was a result of abundant Assiminea sp. at BH. The density and diversity were the highest in summer while lowest in winter. The mean biomass of macrobenthos was 20.8±6.1 g/m². Seasonal dynamic of biomass was: summer > autumn > spring > winter. The BIO-ENV analysis showed that mean grain size of sediment and height of Spartina were the major factors which affected the abundance of macrobenthos in S. alterniflora salt marsh..3 Abundance and diversity of macrobenthos was higher in S. alterniflora salt marsh which had developed after a longer time than which a shorter time. Community structure and diversity of macrobenthos were closely related to the development of salt marsh. After being introduced into Yangtze Estuary, S. alterniflora influenced the macrobenthos by competing with Phragmites australis and changing the hydro-geological conditions. In the beginning of foundation of S. alterniflora salt marsh, macrobenthos were mainly composed of gastropod. The abundance and diversity were at a lower level while species richness （d=2.18） and diversity （H’=2.19） were both lower than in P. australis salt marsh （d=2.61, H’=2.29）. With the passage of time, species numbers of polychaeta increased （from 3 to 6） while species numbers and abundance of macrobenthos increased. A new pattern of macrobenthos was formed. Species richness （d=2.70） and diversity （H’=2.48） of macrobenthos were higher in S. alterniflora salt marsh than in P. australis salt marsh （d=2.19, H’=2.09）. But it would take a long period for the foundation of new community.4 8 classes of ecosystem services value of S. alterniflora salt marsh in Yangtze Estuary were analyzed. The value was 317 570 000 Yuan per year. The value per unit area was 697,000 6.97Yuan ha^-1.yr^-1, which was 275% more than the average value in the Yangtze Estuary. The services value from more to less was the value of land forming, atmosphere regulation, material production, wave dissipating, science culture, nutrient cycle, environment purification and biodiversity. The value of land forming and atmosphere were up to 71% of the total value. The ecosystem service values of S. alterniflora salt marshes per unit area were higher than or equal to the mean value in the Yangtze Estuary. This showed that S. alterniflora could be used as engineering species for ecological restoration. The value per unit area of land forming, material production and atmosphere regulation were higher in the Yangtze Estuary than in Hangzhou bay.While the value per unit area of environment purification and biodiversity and atmosphere regulations were higher in Hangzhou bay. This was resulted by difference of economic geography and biomass of S. alterniflora between two areas. Taking different use target into account, ecosystem services of S. alterniflora salt marsh might have different value. S. alterniflora salt marsh should be dealt with different ecosystem management ways.In conclusion, the abundance and diversity of macrobenthos in S. alterniflora salt marsh was at the mean level in the Yangtze Estuary, and presented a trend of increasing gradually from the upper to the lower region along the environmental gradient. The abundance was affected by mean grain size of sediment and height of Spartina. In the beginning of foundation of S. alterniflora salt marsh, the abundance and diversity of macrobenthos were at a lower level, especial for the crabs. With the time went by, a new pattern of macrobenthos community formed. The abundance and diversity increased gradually, even higher than in P. australis salt marsh. S. alterniflora salt marsh had a high value of ecosystem services. But we should envisage the negative effect impacted by S. alterniflora. It grows quickly, competes with the native species strongly and changes the habitats and biodiversity if the local salt marshes, especially in some mud flats fit for shellfish culture. S. alterniflora salt marsh decreased the habitats for shellfish and wetland birds. So, we should evaluate S. alterniflora in a dialectic opinion. S. alterniflora salt marsh should be dealt with different ecosystem management ways. We should control S. alterniflora in aquaculture area and wetland bird’s habitats and develop S. alterniflora salt marsh in a scientific model in other areas.更多还原