陕北安塞退耕地持久土壤种子库与地上植被的对应关系

通过研究陕北安塞退耕3~31 a的阴阳坡10个样地的持久土壤种子库特征及其与地上植被的关系,分析持久土壤种子库在植被恢复中的作用。结果表明：调查样地持久土壤种子库由15个科36个物种组成,种子密度在1 908~12 617粒/m2之间,1年生物种占80%,随着退耕演替的进行,种子库中1年生物种比例呈下降趋势,多年生物种比例呈上升趋势,地带性物种在持久种子库中的比例也随退耕时间的延长而增加,物种数和种子库密度均随退耕演替先增大后降低;持久土壤种子库与地上植被的相似性较低,Serensen相似性系数为0.21~0.42;通过对适宜物种的确限度及土壤种子库大小的分析,认为该区退耕地的持久土壤种子库具有一定的植被恢复潜力。

Relationship between persistent soil seed bank and above-ground vegetation on abandoned farmland in An'sai of the North Shaanxi Province

In order to find the effects of persistent soil seed bank on the vegetation restoration on abandoned farmland in Hilly-gully area of Loess Plateau,investigation on the relationship between the persistent soil seed bank and the above-ground vegetation was taken.10 plots which abandoned for 3 to 31 years on different aspect were collected in this study.The result showed that there are 36 species belong to 15 families in the soil seed bank,the main species are annual,and also included some perennial and semi-shrub.The density of seed bank is between 1 908 seeds/m2 and 12 617 seeds/m2,and 80% is of annual.The proportion of annual declined with the time of rehabilitation,but the proportion of perennial and the typical species in this area increased with the time.The number of the species and the density increase firstly and then descend with the time.The serensen similarity index of above-ground vegetation and soil seed bank is 0.21-0.42.By the analysis of the fidelity of plants,all the preferential species in the area had the persistent soil seed bank,thus,it is considered that the persistent soil seed bank can help the vegetation restoration in part.