关键词: 锐齿槲栎林, 环境因子, 物种多样性, 更新特征, 太白山

Abstract: [Objective] The characteristics of regeneration of arbor trees in Quercus aliena var. acuteserrata forest in Taibai Mountain were studied to explore the relationship between regeneration and environmental factors, in order to provide a theoretical basis for understanding forest dynamics and forest management in this region.[Method] The status of regeneration and environmental factors of the Quercus aliena var. acuteserrata forest in Taibai Mountain were systematically investigated by setting up 21 and 12 sample plots on the south and north slopes, respectively from July to September 2009 and July to August 2010. The collected data were used to determine the regeneration density, diversity index, height-class structure, and the relationship between the regeneration and environmental factors using Excel 2003 and SPSS17.0 software.[Result] A total of 30 tree species with regeneration were recorded, in which Acer grosseri, Litsea moupinensis var. szechuanica, Quercus aliena var. acuteserrata, Symplocos paniculata, Crataegus hupehensis, and Viburnum betulifolium were the most important regeneration species. For each species, the importance value (IV) was more than 20%, and the IVs of six species accounted for 69.31% of the sum IVs of all regeneration species. The total regeneration density was 9 696.97 individual·hm^-2 and mainly concentrated at the seedling stage. The regeneration density in seedlings (H<1.3 m) was nearly 3 times of that in saplings (1.3 m ≤ H<3 m). Further analysis showed that the regeneration density was an inverse J-shape distribution with height-class. Regenerated saplings of Q. aliena var. acuteserrata with a height of 210-300 cm were not found in the forest, implying a failure to regenerate because that couldn't form a complete sequence of regeneration sizes in the understory. There were significant differences among different plots in regeneration densities and diversity indices (including species richness, Simpson index and Shannon-Wiener index), indicating that the distribution of regeneration was uneven, and tended to be patchy. Multivariate linear stepwise regression analysis showed that the main environmental variables influencing the total regeneration density were slope direction, total P content, slope gradient and organic matter content, which explained 73.2% of the total variation. Total P content and slope direction were the main environmental variables affecting regeneration diversity.[Conclusion] There were abundant regenerated tree species in the Q. aliena var. acuteserrata forest in Taibai Mountain, indicating certain regeneration ability. However, Q. aliena var. acuteserrata as the most dominant species couldn't complete natural regeneration in the understory, therefore, in forest management, creating open habitats (such as gaps in the forest) to promote regeneration, meanwhile, attention should also be paid to the effects of slope direction, total P content, slope gradient and organic matter content on regeneration, the habitat with the cooler wet slope, gentle slope, low soil P and organic matter content is conducive to the regeneration of arbor trees.

Key words: Quercus aliena var.acuteserrata forest, environmental factors, species diversity, regeneration characteristics, Taibai Mountain