Cushion plants can affect wind speed and sediment movement patterns which probably modify the water and sediment redistribution along slopes and increase the accumulation of seeds under and around their canopies. This study was carried out to assess the spatial variability of soil seed bank (SSB) and seed bank composition around cushion plants to estimate the SSB potential for restoration of degraded area. Twenty cushions of Onobrychis cornuta were selected in a mountainous rangelands in northern Alborz in Iran, measuring density, richness and composition of SSB at four locations of each cushion (upslope edge, downslope edge, center and outside). SSB composition and density were determined by seedling emergence method. The results showed that the locations of cushions had significant effect on density and richness of the SSBs. The highest SSB density and richness were observed in the center and upslope edge of the cushions while there was no significant differences of density and richness between downslope edge and outside (bare grassland soil) of the cushions. In addition, the results showed that seed bank composition was highly correlated between the four locations in the same cushion. We concluded that cushion plants can act as seed traps specially trapping seeds dispersed by barochory and hydrochory and therefore, play an important role in conservation and recovery of degraded areas.

中文翻译：

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亚高寒退化草地垫层植物土壤种子库空间变化

垫形植物会影响风速和沉积物运动模式，这可能会改变水和沉积物沿斜坡的重新分布，并增加其冠层下方和周围的种子积累。本研究旨在评估垫层植物周围土壤种子库 (SSB) 和种子库组成的空间变异性，以估计 SSB 恢复退化区域的潜力。在伊朗 Alborz 北部的山区牧场中选择了 20 个 Onobrychiscornuta 垫子，测量每个垫子的四个位置（上坡边缘、下坡边缘、中心和外侧）的 SSB 的密度、丰富度和组成。SSB 组成和密度通过出苗法测定。结果表明，垫层的位置对SSBs的密度和丰富度有显着影响。在垫层的中心和上坡边缘观察到最高的 SSB 密度和丰富度，而下坡边缘和垫层外部（裸草地土壤）的密度和丰富度没有显着差异。此外，结果表明种子库组成在同一垫层的四个位置之间高度相关。我们得出结论，垫层植物可以作为种子陷阱，专门捕获被压力和水力分散的种子，因此在退化地区的保护和恢复中发挥重要作用。结果表明，种子库组成在同一垫层的四个位置之间高度相关。我们得出结论，垫层植物可以作为种子陷阱，专门捕获被压力和水力分散的种子，因此在退化地区的保护和恢复中发挥重要作用。结果表明，种子库组成在同一垫层的四个位置之间高度相关。我们得出结论，垫层植物可以作为种子陷阱，专门捕获被压力和水力分散的种子，因此在退化地区的保护和恢复中发挥重要作用。