依据空间代替时间的方法,研究地表火干扰下不同恢复阶段栎类群落幼苗库的动态特征.结果表明:在地表火干扰后栎林群落内有木本幼苗25科37属49种,随着火烧迹地植被的恢复,乔木幼苗种类数量增多,灌木幼苗数量减少,但栎类幼苗始终占据优势；林下幼苗库的密度随恢复时间增加逐步变小,栎类幼苗密度则呈现出从高到低再升高然后变低的趋势,栎类幼苗密度在火后1年最高,平均达到(2.30±2.9)株·(10 m2)-1；林下幼苗库恢复1年与恢复10年之间、恢复15年和对照林的密度差异显著,但恢复1年与恢复5年、恢复10年的幼苗库与对照林的幼苗密度之间没有显著差异；栎类幼苗密度变化出现2个过程,恢复1年与恢复5年、恢复10年与恢复15年幼苗密度之间有显著差异,但不同恢复阶段的栎类幼苗库与对照林相比没有显著差异；幼苗库不同恢复阶段的ShannonWiener指数(H′)之间有极显著差异；相邻恢复阶段共有的幼苗物种较多,相似系数较大,以每2种不同恢复阶段的栎林群落进行比较,其共有物种数量为4～17种.随演替时间的增加,乔木实生苗比例逐渐增加,乔木根蘖苗的比例不断减少,到植被恢复后5年,栎类群落林下没有发现根蘖苗生存,而林下灌木幼苗也在恢复10年的群落内消失.林火干扰对栎类Ⅰ、Ⅱ和Ⅲ级的幼苗高度分配和苗木转化率有显著影响,但火烧干扰对Ⅳ级以上幼苗的高度分布和转化率影响不显著.%Using a space substitute for time approach, this paper investigates the dynamic characteristics of the seedling bank of Quercus spp. community at different restoration stages under the disturbance of ground fire in Bao-tianman National Nature Reserve. The results showed that there were 49 species of wood seedlings belonging to 37 genera of 25 families at different restoration stages after fire in Quercus spp. community, with the recovery of the vegetation in the burned area, the amount of the wood species seedling increased and the shrub species seedling de-creased, but the Quercus spp. seedling always maintained prevalence at different stages; the density of the seedling bank under the forest became smaller as the restoration time prolonged, the density of the Quercus spp. seedling showed a high-low-high fluctuation. The density reached the highest amount of (9. 34 ±4. 71) plant/10 m2 1 year after fire; there were a significant differences between the seedling bank under the forest 1 year after fire and 10 years after fire, and between 15 years and the primeval forest, but no significant difference was found between 1 year after fire and 5 years after fire, and between 10 years after fire and the primeval forest. The density change of the Quercus spp. seedling showed a 2-stages process and there were a significant differences between 1 year after fire and 5 years after fire, and between 10 years and 15 years, but no significant difference was found between the seed-ling bank of Quercus spp. community at different restoration stages and the primeval forest; the Shannon-Wiener in-dex of the seedling bank showed a great difference at different restoration stages. The adjacent recovery stages shared more seedling species and the similarity index was higher. Comparing every 2 Quercus spp. communities at different restoration stages, they shared 4 to 17 species. With the succession time prolonged, the percentage of the wood seedlings increased gradually while the percentage of the root sprout seedling declined; 5 years after the restoration of the vegetation, no root sprout seedlings existed under the Quercus spp. forest, while the shrub seedlings under forest also disappeared in the community of 10 years after the recovery. It showed that the disturbance of forest fire had a significant influence on the distribution of the height of seedlings of Quercus spp. Ⅰ , Ⅱ and Ⅲ and the trans-formation efficiency of the nursery stock, but no significant influence was found on those of seedlings above Quercus spp. Ⅳ.
展开▼
