【摘要】 :(1)采用萌发试验法对内蒙古冷蒿(Artemisiafrigida)草原土壤种子库特征及其在不同放牧压力下的变化进行了研究。(2)冷蒿草原可萌发种子库由4种多年生禾草、11种多年生杂草及3种1年生植物所组成。(3)每样中的可萌发种子量变化于45到305之间,平均102/样。多年生禾草、多年生杂类草及1年生植物的土壤中种子量分别占总可萌发种子库的46.57%、51.96%和1.57%。多年生禾草糙隐子草(Cleistogenessquarrosa)是种子库中的优势种。(4)土壤可萌发种子库与地上植被间的相关程度较低。但轻度放牧提高了种子库与植被的相似度。(5)冷蒿草原多数种类的可萌发种子在土壤中的分布为集聚型分布。(6)可萌发种子库的种类组成以及多数种类的土壤中种子量均随放牧压力的增加而减少;但放牧增加了整个可萌发种子库分布的均匀度。更多还原

【Abstract】 Features of germinable seed bank in Artemisia frigida grassland in Inner Mongolia and their responses to grazing were studied using germination test. Four perennial grasses, eleven perennial forbs and three annual species were detected in the seed bank. The number of germinable seeds per soil sample ranged from 45 to 305 with an average of 102. Seeds of perennial grasses, perennial forbs and annuals accounted for 46 57, 51 96 and 1 47 percent of the total seed bank, respectively. Perennial grass Cleistogenes squarrosa was the most abundant species in the seed bank. A relatively low similarity was found between the soil seed bank and its associated vegetation. However, light grazing increased the degree of the correlation. Distribution patterns of the buried seeds of most species were clumped. Species richness of the seed bank and quantities of the germinable seeds of most species were reduced by grazing disturbance, while grazing impact increased evenness of the seed bank distribution.更多还原