[Seed rain, soil seed bank and seedling regeneration of Quercus aliena var. acureserrata in different slope directions on the middle Qinling Mountains, China].

We studied the seed rain, seed pool quantity and quality dynamics, and seedling develop-ment of natural Quercus aliena var. acureserrata forests in different slopes (sunny, semi-sunny, semi-shady and shady slope) of the middle Qinling Mountains, China. The results showed that seed rain of Q. aliena var. acureserrata generally began at mid-August, peaked from mid-late September to early October, and ended in mid-early November. The dissemination process, occurrence time, and composition of seed rain in four slopes were different. The seed rain intensity of the semi-sunny slope was the highest, which was 134.13 seeds·m, followed by sunny slope, semi-shady slope, and shady slope. The seed rain on the sunny slope occurred first, and the duration of the whole and peak period were the longest. The seed rain on the shady slope occurred at the latest, and the duration of the whole and peak period were the shortest. The seed viability and mature seeds proportion were semi-sunny slope > sunny slope > semi-shady slope > shady slope. From the end of the seed rain to the August of the next year, the size of soil seed bank was semi-sunny slope > sunny slope > semi-shady slope > shady slope. The number of mature, immature and nibbled seeds and seed vigor of soil seed bank showed a decreasing trend with time, while the number of moldy seeds increased. The seeds in soil seed bank mainly existed in the litter layer, followed by the 0-2 cm soil layer, with few seeds in the 2-5 cm soil layer. The seedling density of Q. aliena var. acureserrata was significantly different among the four slopes. The semi-sunny slope, with the highest seedling density, was more suitable for seed germination and seedling growth of Q. aliena var. acureserrata than other slopes.