东太湖3种沉水植物群落区底泥种子库与幼苗库

General seed banks and seedling banks of 3 dominant submerged macrophyte community in east Taihu Lake

底泥种子库在沉水植物恢复中具有重要作用。研究了东太湖3种优势沉水植物苦草（Vallisneria natamtsL．）、马来眼子菜（Potamogeton malaianusMiq）和做齿眼子菜（Potamogeton maackiantts）群落区的广义种子库和种子库采样区的幼苗库。2005年1月，在3种植物的优势群落区各随机采取泥样样方9个，25℃的培养箱内，光照周期L：D=12：12条件下，采用种子萌发法鉴定土壤种子库。研究结果显示，实验室内种子库在5个月内全部萌发完毕。3种沉水植物群落区的广义种子库大小分别为1003．33粒·m^-2，1446．67粒·m^-2和910粒·m^-2，优势利，植物的种子占相应区域种子库总量的97％以上。从种子库结构上看，苦草主要以无性繁殖为主，微齿眼子菜以有性繁殖为主，马来眼子菜则无性繁殖和有性繁殖同等重要。对比研究采样点区域植物群落当年植物幼苗的萌发情况，结果表明，幼苗库在数量上要远小于其相应的种子库的规模，幼苗库植物种类要多于相应的种子库，生物多样性也较种子库高，幼苗库与种子库的相似系数在0．33-0．67。

Sediment seed bank plays important role in macrophyte restoration in Lake. General seed banks and seedling banks of 3 kind of macrophyte cOlnlnunity dominated respectively by Vallisneria spiralis, Potarnogeton malaianus and Potamogeton maackianus in east Taihu Lake were studied. 9 sediment samples sampled randomly in each comlnunity area dominated respectively by 3 submerged lnacrophytes in January, 2005. Sediment community seed banks were identified ill culture hutch by method of seed germination in the condition of 25℃ and illumination period of 12 h.d^-1. The results .showed that the germination of all the seed banks was carried out in five months. The densities of the three community seed banks were respectively 1 003.33 seeds·m^-2, 1 446.67 seeds, m 2 and 910 seeds·m^-2, and dominant species in each area took up more than 97%. The structure of the general seed banks was different. For 14 spiralis, the proportion of vegetative propagation is higher than sexual propagation （seeds）, while for P maackianus, it is converse, and the vegetative propagation and sexual propagation is equally important for P malaianus. There were differences in the alnount and structure between the seed bank and seedling bank in the sampling area. The amount of seedling bank was much less than seed bank, while the quantity of species and species diversity of seedling bank were higher than seed bank. The similarity coefficient between seedling bank and seed bank is 0.33-0.67.