晋西刺槐人工林生长分化过程分析

Growth and differentiation process of Robinia pseudoacacia plantation in Western Shanxi Province

利用56株解析木,分析了不同密度、坡向、坡位刺槐林生长分化特征。研究表明:不同密度、坡向、坡位的林分生长量、速生期长短不一,导致了林木分化。分化过程主要表现在分级木的相互转换中。刺槐林以树高、胸径表述的转换率分别为:35.7%,21.4%。将坡向按转换率从高到低的排序为:阳坡、半阳坡、阴坡。不同坡向以树高、胸径表述的转换率分别为:41.7%、38.5%、0,25.0%、23.1%、0。密度多大将会影响林分生长,须分坡向、坡位进行量化。自造林后第几年林木开始分化形成分级木,须确定准确林龄,这对人工林集约经营有指导意义。

By using 56 analytic trees, we analyzed the differentiation characters of Robinia pseudoacacia forests in different stand density ,slope aspect and location. The study shows that different stand density, slope aspect and location lead to different stand increment and different length of fast - growing period, resulting in tree differ- entiation. The process of tree differentiation is mainly expressed by classified stems transformation. The transfor- mation rate of Robinia pseudoacacia plantation that expressed by DBH and height respectively are 35.7% and 21. 4%. The transformation rate of different slope aspect which is sequenced from high to low is the following order ： sunny slope, half - sunny slope, shady slope. The transformation rate of different slope aspect which expressed by height are 41.7%, 38.5%and 0, while expressed by DBH are 25.0%, 23.1% and 0. We need to quantita- tive slope aspect and location separately to determine how much the density will affect the growth of plantation. It has guiding significance to plantation intensive management to determine which year trees began to form classified stems after planting.