坝上草原退耕地植被不同恢复处理土壤种子库研究

采用野外调查取样和室内实验相结合的方法,研究坝上草原退耕地土壤种子库的物种组成、密度和物种多样性等特征.结果表明:自然恢复、浅耕处理和深耕处理3种不同恢复措施下,土壤种子库物种丰富度(种)大小为浅耕处理(18)>自然恢复(15)>深耕处理(14);自然恢复处理、浅耕处理和深耕处理土壤种子库密度分别为23 949粒·m-2、15746粒·m-2和10600粒·m-2,浅耕处理和深耕处理分别比自然恢复处理减少34.3%和55.7%;不同恢复方式下土壤种子库与地上植被的物种密度的对应关系可用三次曲线来表示.土壤种子库间有较高的相似系数,但随着干扰程度的增加而减少.

Soil seed bank under different diversity restoration measure in the grassland of Bashang region

Field surveys and laboratory experiments were conducted to study the characteristics of soil seed banks such as species composition, density and diversity in Bashang grasslands. Results show that soil seed bank richness under shallow plough treatment (18) is greater than that under nature restoration (15) and that under nature restoration is in turn greater than that under deep plough treatment (14). Soil seed bank density under nature restoration, shallow and deep plough treatments, is respectively 23 949, 15 746 and 10 600 seed·m^-2. Soil seed bank density under shallow and deep plough treatments respectively decreases by 34.3% and 55.7% than under nature restoration. Regression analysis indicates that the relationship between density of soil seed bank and that of associated vegetation has a cubic-shaped curve. There is high similarity of soil seed bank among diversity restoration measures. However, the similarity decreases with increasing artificial disturbance.