中文摘要：

自然幼苗新生和树建立被各种各样的环境因素影响。在这研究，我们证实八，八，六，和四个独立森林站(每个看台进一步被划分成五次要情节)分别地基于高度的坡度，看台密度，斜坡地点，并且在一棵松橡树在树幼苗新生上调查环境因素的效果的斜坡方面混合了森林。结果显示幼苗密度在到 1,665 m 的 1,283 m 的高度是显著地更高的，而树苗密度没与高度不同。幼苗和树苗密度在 1,835 m 显著地减少了。上面的斜坡上的幼苗密度比中间、更低的斜坡上的那些高得多，而树苗密度没有差别。树苗密度从西南逐渐地减少了(20 吗？？

英文摘要：

Natural seedling regeneration and tree establishment are affected by various environmental factors. In this study, we established eight, eight, six, and four independent forest stands （each stand was further divided into five subplots） respectively based on the altitudinal gradient, stand density, slope location, and slope aspect to investigate the effects of environmental factors on tree seedling regeneration in a pine-oak mixed forest. The results indicated that the seedling density was significantly higher at altitudes of 1,283 m to 1,665 m, whereas the sapling density did not differ with altitudes. The seedling and sapling density decreased significantly at 1,835 m. The seedling densities on the upper slopes were much higher than those on the middle and lower slopes, whereas the sapling density had no difference. The sapling density decreased southwest （20°-75°） whereas gradually from the it increased on the shady slopes to the northeast （40°）. The seedling density increased from southwest （20°） to northeast （40°The seedling and sapling densities increased with the stand density （850 trees ha-1 to 1,525 trees ha-1） whereas the sapling density was significantly lower in stands （1,9oo trees ha-O. Principal components analysis showed that the slope aspect and stand density had more important roles in tree regeneration in this study region compared with the other two factors. Therefore, our findings suggest that it will be beneficial to keep stands at a moderate density on shady slopes. Appropriate thinning of higher density stands is also expected to promote the natural regeneration of pine-oak mixed forest.