不同封育年限宁夏荒漠草原土壤种子库研究

A Study on soil Seed Bank in Desert Steppe of Different Enclosing Years in Ningxia

针对宁夏天然草原实施禁牧封育的现状,采用种子萌发法对不同封育年限的荒漠草原土壤种子库进行了研究。结果表明:种子萌发主要集中在0-5cm土层中,6-10cm土层种子萌发较少,0-5cm土层中,随封育年限的增加,一年生草本植物逐渐减少,多年生草本植物增加,半灌木或灌木逐渐增加;在垂直分布上,随土层深度的增加单位面积的种子数量减少;土壤种子库的密度随封育时间的增加而增加;在0-5cm土层中,封育使土壤种子库的物种多样性和丰富度明显增加;在0-5cm土层和6-10cm土层中,土壤种子库和地上植被的相似性都较低,在0-5cm土层,随封育年限的增加土壤种子库与地上植被的相似性程度逐渐增加。

According to the present situation of Ningxia natural grassland enclosure,the method of seed germination was used to study soil seed bank in desert steppe of different enclosing years.The result shows： seed germination mainly occurred in 0-5 cm soil,seed germination in 6-10 cm soil was less.In 0-5 cm soil,annual herbs gradually reduce,the perennial herbs increase,half shrubs or shrubs increase gradually with the increase of the enclosing year.In vertical distribution,along with the increase of soil depth,the seeds decreased in the number of unit area.The density of the soil seed bank increased with increase of enclosing year.In 0-5 cm soil,enclosing made the species diversity of the soil seed bank and abundant degree increase.In 0-5 cm and 6-10 cm soil,the soil seed bank and the similarity of above-ground vegetation are low.In 0-5 cm soil layer,with the increasing of enclosing year,soil seed banks and the similarity degree of above-ground vegetation increase gradually.