【摘要】 土壤种子库对岩溶山地退化植被恢复具有重要意义。采用萌发法,比较了重庆典型岩溶山地处于不同生态演替序列的自然林地、次生林地、灌草坡、坡耕地、人工林、弃耕撂荒地等土地利用系统的土壤种子库分布特点。喀斯特山地各植被类型的土壤中贮藏着丰富的种子,每个40cm×25cm×15cm土柱内储藏有227.4~454.8粒种子,土壤种子集中分布在土壤表层(0~5cm),乔灌种子主要分布于0~5cm土壤层。土地利用强度越大,木本植物种子越少,草本植物种子越多,且以农田杂草为主,土地利用方式的变化(如陡坡开垦)是对次生植被及其种子库的主要威胁;坡度、溶沟、溶隙等土壤分布环境和土壤水分等也对喀斯特山地的种子密度产生影响,这就使得种子密度在不同地点及植被类型间相差很大,生境异质性是种子库分布模式的决定因子。更多还原

【Abstract】 Soil seed banks have a important significance to the degraded vegetation restoration of karst mountains. Using germina- tion method, the distribution of soil seed bank of different land use systems such as natural forest, secondary forest, shrub-herb land, sloping cropland and fallow wasteland which located in different ecological evolve sequence were studied in Chongqing representa- tive karst mountains. The results showed that there were abundant seeds stored in soils under different karst vegetations. There were 227.4~454.8 seeds for each of 40 cm×25 cm×15 cm soil unit. The soil seed banks distributed in soil surface layers (0~5 cm) concen- tratively, the seeds of trees and shrubs distributed in soil surface layers (0~5 cm) mostly also. With the increase of land use intensity, the amount of woody species seeds decreases while herbage seeds increase, particularly, dominated by the farmland weed. The changes of land utilization are the most influence on secondary forest and its soil seed banks. Soil distribution environment such as gradient, karst gouge, karst gap, and soil water all influenced soil seeds density of karst mountains, the soil seeds density in different places or of different vegetation types differentiated obviously. Therefore, the heterogeneity of microhabitat type is the deciding fac- tor of soil seed banks distributing models.更多还原