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采用野外定点取样与室内培养相结合的方法,研究了呼伦贝尔4种退化沙地土壤种子库密度多样性。结果表明:土壤种子库密度随草地沙化程度的加重而下降,且不同沙化阶段其下降率各异,从固定沙地到半固定、半流动、流动沙地,土壤种子库密度分别下降75.7%、83.4%和84.2%。种子库物种数的变异从固定沙地到半流动沙地变化较小,而到流动沙地变化较大,主要为一二年生植物(50%),多年生草本和灌木比例相对较少。土壤种子库物种多样性指数变化与密度变化不一致,其中半固定沙地最大,流动沙地最小。种子库群落相似性指数变化幅度在0.6087～0.9355之间,说明其空间异质性较小。
Using the combination of field fixed point sampling and indoor culture, the density diversity of soil seed bank in four degenerated sandy land of Hulunbeier was studied. The results showed that the density of soil seed bank decreased with the increase of desertification degree, and the rate of decline was different in different desertification stages. From fixed sandy land to semi-fixed, semi-mobile and mobile sandy land, the seed bank densities decreased by 75.7% 83.4% and 84.2%. Variation of species number in the seed bank changed little from fixed sandy land to semi-floating sandy land, but fluctuated to mobile sandy land, mainly of annuals and perennials (50%), with relatively few perennial herbs and shrubs. Soil seed bank species diversity index changes and density changes inconsistent, of which semi-fixed sandy land maximum, the smallest mobile sand. The similarity index of seed bank community varied from 0.6087 to 0.9355, indicating that the spatial heterogeneity of seed community was small.