引江济汉工程是从长江荆江河段龙洲垸引水至汉江高石碑镇兴隆河段的大型输水工程，该工程可能引起长江中下游地区环境因子及植被特征变化。为揭示这种变化，在引江济汉工程正式分流前，对长江中游河漫滩种子库进行调查研究。以长江中游较为典型江段中的石首芦苇站河漫滩、岳阳七弓岭河漫滩及九江沙洲村河漫滩为研究对象，利用种子萌发法结合野外植被群落调查，研究长江中游河漫滩种子库的种类组成及种子库与地表植被的关系。结果表明，（1）种子库种子密度九江（6541±5534）seeds∙m-2>岳阳（3840±2948）seeds∙m-2>石首（1981±1818）seeds∙m-2，其中九江与岳阳、石首差异显著（P<0.05），而岳阳与石首差异不显著；物种数为九江（39）>石首（35）>岳阳（30），禾本科与菊科植物种类较多，且一年生物种明显多于多年生物种；所有萌发物种中有19个物种为3个位点共有，19个共有种皆为3个位点中的优势种，但在不同位点，不同优势种的种子密度与分布频率差异很大。（2）种子库与地表植被的物种相似性都较低，岳阳（0.25）>九江（0.173）>石首（0.127），其中石首与岳阳种子库物种数高于地表植被物种数，而九江反之；3个位点种子库的Shannon多样性指数与Plelou均匀度指数均高于地表植被；石首与九江种子库Simpson优势度指数高于地表植被，而岳阳反之；3个位点种子库Shannon、Plelou、Simpson指数的变化趋势与地表植被的变化趋势一致，表现为石首、九江高而岳阳低的特征。%Water transfer project from Yangtze River to Hanjiang River is a large-scale water diversion project that begins from Longzhouyuan of Jingjiang Reach of Yangtze River to Xinglong Reach of Gaoshibei Town, belonging to one of the middle and lower reaches of Hanjiang River regulation project. It has no doubt that the project will lead changes of water quality, sediment loads, water level and so on, which in turn will result in the alterations of the biological components of natural. Soil seed bank can affect species composition, spatial structure and succession dynamics of vegetation. So it is necessary to investigate the seed bank of middle reach of Yangtze River before carrying out the "Water transfer from Yangtze River to Hanjiang River" project, which aims at offer the basic data for researching effects of large hydrographic engineering on the vegetation successions of flood plains. The study takes Reed station flood plain of Shishou City, Qigong Ridge flood plain of Yueyang City and Shazhou Town floodplain of Jiujiang City in different river links of middle reaches of Yangtze River as research objects, studying on the species composition, spatial distribution and the relationships between the seed bank and vegetation by seed germination methods in combination with field vegetation community survey. The results are as follows, (1) In seed bank density comparison: Jiujiang (6541±5534) seeds∙m-2>Yueyang (3840±2948) seeds∙m-2>Shishou (1981±1818) seeds∙m-2, seed bank density in Jiujiang is significantly differ from Yueyang and Shishou (P<0.05), but Yueyang and Shishou are not. In germination species, Jiujiang (39)>Shishou (35)>Yueyang (30), Gramineae and Composite plants are the main species, and annual species significantly more than the perennial species. 19 species are common and cover all the advantage species in all these three regions, but the seed density and distribution frequency of them in different sites are varies considerably. (2) The species similarity of seed bank and vegetation is very low, Yueyang (0.25)>Jiujiang (0.173)>Shishou (0.127). The seed bank species of Shishou and Yueyang is higher than vegetation, and Jiujiang opposite. The Shannon diversity index and Plelou evenness index of seed bank are higher than vegetation. The Simpson dominance-index of seed bank of Shishou and Jiujiang is higher than vegetation, and Yueyang opposite. The Shannon diversity index, Plelou evenness index and Simpson dominance-index were the same trend at different site, V-shaped.
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