蒙古栎红松林物种组成和结构动态的研究

 通过对蒙古栎红松林3个年龄阶段物种和结构动态的研究，结果表明，该类型森林的更新状况良好，早期阶段红松(Pinus koraiensis)和阔叶树的更新数量相同，后期更新树种以红松为主；在森林发育早期阶段蒙古栎(Quercus mongolica)等阳性树种占优势，中期为红松和阔叶树占优势的混交林，后期形成红松占优势的林分；随着森林的发育，灌木和草本层动态呈现复杂的变化。通过对该类型森林直径分布变化的研究得出，在林分发育的早期，阔叶树中大径级木较多，针叶树中小径级木多，在林分发育的后期呈相反的规律。用理论概率模型拟合直径分布表明，韦布尔概率分布模型是描述蒙古栎红松林直径分布的最适模型。

SPECIES COMPOSITION AND STRUCTURE DYNAMICS IN MONGOLIAN OAK-KOREAN PINE FOREST

Dynamics of plant biodiversity and structure were studied at three different stages of Mongolian Oak-Korean pine forest regeneration. Forest regeneration was good in the early period with Korean pine and broad-leaved tree specles having slmilar numbers of individuals regenerating. Later, the number of abundance of Korean pine regeneration comes to exceed that of other tree species. With the development of forest, firstly Mongolian Oak and other shade-intolerant tree species initially dorninate stands, these are replaced by Korean pine and broad-leaved tree species in a mixed stand, while Korean pine dominates older stands. The modeled dynamics of shrubs and herbs were more complex. Analysis of stem diameter distributions showed that there were more large trees of broad-leaved tree species and fewer small trees of conifer species at early stage, but these conditions are reversed at a later stage. Diameter distributions of the different forest stages were fitted with theoretical models. The results showed that Weibull distribution had the best fit in these Mongolian Oak-Korean plne forest.