松嫩平原碱化草甸两个群落土壤种子库动态

Dynamics of soil seed banks of two alkalized meadow communities in Songnen Plain of China

对松嫩平原碱化草甸中星星草+羊草群落和星星草群落土壤种子库组成的季节动态进行了研究。结果表明:在4—9月,2个群落的土壤种子库均以多年生草本植物为主,星星草+羊草群落共出现12种,而星星草群落为10种,并均以星星草占最大比例,分别为66·8%～92·9%和75·3%～97·7%。种子库相似性系数在6月最大。星星草+羊草群落种子库密度在7月份最大,为(26560·0±7256·9)粒·m-2,星星草群落在8月最大,为(25590·0±6443·7)粒·m-2;而2个群落的物种多样性指数和均匀度指数则分别在7月和8月最小。

The study on the seasonal dynamics of soil seed banks of two alkalized meadow communities, i. e. , Puccinellia tenuiflora and P. tenuiflora ＋ Leymus chinensis in Songnen Plain showed that from April to September, the soil seed banks were dominated by the seeds of perennial herbaceous species, with 10 species in P. tenuiflora community and 12 species in P. tenuiflora ＋ L. chinensis community, and P. tenuiflora seeds occupied a great proportion, being 75.3%-97.7% in P. tenuiflora community and 66. 8%--92. 9% in P. tenuiflora ＋ L. chinensis community. The seed banks of the two communities had the highest similarity in June. P. tenuiflora community had the maximal density of seed bank （25590. 0 ＋ 6443.7 seeds· m^-2） in August, while P. tenuiflora ＋ L. chinensis community had it （26560. 0 ＋7256. 9 seeds·m^-2） in July. The indices species diversity and evenness of the two communities were the minimum in July and August, respectively.