子午岭天然柴松林土壤种子库

Soil seed bank of Pinus tabulaeformis f.shekannesis natural forest in the Ziwuling mountains

采取子午岭天然柴松林地3个坡位与1个对照区共4个大样地54个小样方的土壤样品,通过室内种子萌发和地上植被调查相结合的方法对其种子库进行研究,以揭示其土壤种子库特征及与地上植被的关系。结果显示：1）土壤种子密度平均为1 496.7粒/m^2,最小为1 240.0粒/m^2,最大为1 785.0粒/m^2,荒山对照区为510.0粒/m^2;2）种子库的垂直分布格局显示,近90%的种子储存于枯枝落叶层和0-7.5 cm土层中;3）研究中共统计到植物种32种,分属于20科,其中多年生草本和常绿灌木种子比例最高,分别占种子库种子总数的48.3%和41.9%;4）不同坡位的物种丰富度指数介于2.523-3.082之间,而物种多样性指数介于1.458-1.781之间,其中中坡物种丰富度指数最大而多样性指数最小,上坡多样性指数和均匀度指数都最大;5）各坡位地上植被主要建群植物种中,除白颖苔草、大披针苔草、胡枝子、唐松草在对应坡位的土壤种子库中出现且分别占该坡位种子库的19.7%、2.1%和0.8%、1.7%和3.1%0、.4%外,其他建群种如榛子、子、地榆等在种子库中均未出现,种子库不能很好地反映地上植被组成,部分未出现物种与其自身萌发性质有关;6）土壤种子库中柴松种子所占比例约为0.6%（地上植被调查发现）,柴松林下有更新幼苗,约5-7粒/m^2,说明种子库具有潜在萌发能力,森林具备一定的自我更新能力。

The soil samples of 54 quadrates in 4 sample plots which included 3 plot on different position of slope and 1 plot of contrast in the Pinus tabulaeformis f.shekannesis natural forest of Ziwuling Mountains were collected.It was studied combing the germination methods in house and investigation in ground,in expectation of opening out the characters of soil seed bank and the relationship with the aboveground communities.The result showed： 1） The average soil seed density was 1 496.7 seed/m^2,the minimum density was 1 240.0 and the maximum density was 1 785.0 seed/m^2.The seed density in the comparison zone of barren hill was 510.0 seed/m^2.2） The vertical distribution pattern of seed bank showed that it is nearly 90% of seeds stored in litter layer and 0-7.5 cm upper layer of soil.3） 32 plant species were recorded which belonged to 20 families.Among them,perennial herbs and evergreen shrubs had the highest proportion in seed banks,which accounted for 48.3% and 41.9%.4） The species richness ranged from 2.523 to 3.082 and the species diversity ranged from 1.458 to 1.781 in the slopes.Among them,the middle slope had the maximum of the richness,and the minimum of the diversity,the upper slope had the maximum value of both the diversity and the evenness of the soil seed bank.5） The dominant plants of the aboveground communities on slope,such as Ostryopsis davidiana Decaisne,Cotoneaster acutifolius Turcz,Sanguisorba officinalis Linn and so on hadn＇t been recorded in the seed bank,except Carex rigescens（Franch） V.krecz,Carex lanceolata Boott,Lespedeza bicolor Turcz,and Thalictrum alpinum Linn accounted for 19.7%,2.1% ＆ 0.8%,1.7% ＆ 3.1%,and 0.4% of the soil seed bank in the corresponding slope.The plant species composition of soil seed banks did not closely reflect the composition of aboveground communities.Some plant species not emerged out owing to their own characters of germination.6） The proportion of Pinus tabulaeformis f.shekannesis seeds was about 0.6%.In the investigation of aboveground communities,it was discovered that there were a few seedlings of Pinus tabulaeformis f.shekannesis on the forest floor,and about 5-7 seed/m^2 which indicate that the seed banks have potential germination and the forest ever has some abilities of self-renewal.