紫茎泽兰入侵对林分土壤可萌发种子库特征及生物多样性的影响

为了探讨不同程度紫茎泽兰入侵对林地土壤可萌发种子库特征及生物多样性的影响,选择6种不同类型的林地开展了相关研究。采用野外调查植被类型及土壤萌发法进行研究,结果表明:紫茎泽兰的入侵提高了地表物种丰富度,所有样地中共含有31种植物,隶属21个科。各样地中可萌发植物种子量为1 959~37 218粒·m-2,并且主要分布在0~5 cm的土层中,紫茎泽兰的种子量占总量的65.1%,其数量可高达19 833粒·m-2。土壤种子的萌发高峰期主要在前20~40 d,并且双子叶植物居多,占萌发数量的83.3%以上。土壤种子库的物种多样性并不高,与地被植物的相似性较低,无紫茎泽兰入侵的林地也能检测到紫茎泽兰的种子。试验研究表明,紫茎泽兰具有长久性土壤种子库,其种子的数量在土壤种子库中处于绝对优势。

Gre minable Soil Seed Bank Traits and Species Diversity of the Forest Invaded by Eupatorium adenophorum (Sp reng.)

We studied the effect the forest of different degree invaded by Eupatoir um adenophorum( Spreng.) on germinable soil seed bank traits and species diversity with six types of forest.The forest vegetation of surface species richness were in-creased after invaded by E.a denophorum ( Spreng.) , and all seeds were affiliated to 31 species, 21 families.The germ-inable soil seeds in all samples were in 1 959-37 218 seeds/m2 , it mainly distributed in 0-5 cm soil layer, the amount of seeds ofE .adenophorum ( Spreng.) accounted for 65.1%of total number of species, and its seed number was up to19 833 seeds/m2 .Soil seeds germination peak at 20-40 d, and majority type was dicotyledon plants, accounts for more than83 .3% of the number of germination.The species diversity of soil seed bank was not high, and the similarity with vegetation was low, the forest that was not invaded by E.adenophorum ( Spreng.) could also be detected with seeds ofE .adenophorum ( Spreng.) .E.adne ophorum ( Spreng.)had a persistent soil seed bank , and its seeds number in the seed bank was in an absolutely dominant position.