兴安落叶松天然林分级木生长特性分析

本文通过设置样地,作树干解析,阐明了兴安落叶松天然林分级木(优势木、平均木、被压木)生长特性,并分析了分级木生长特性与林分因子和立地因子的关系.结果表明,兴安落叶松分级木在不同年龄阶段有相互转换现象,其转换率38.9%,其中,平均木转换率占50%,优势木和被压木转换率均33.3%.分级木从优势木转平均木和平均木转被压木的转换率最高,相反方向则低.优势木转被压木和被压木转优势木的转换率最低;随着林分密度和林分中落叶松比例增加,分级木相互转换数也增多;分级木转换现象主要集中在海拔＜1 000 m、坡度＜25°、坡向为阳坡、坡位为中下、土壤厚度＞17 cm的林分中;被压木中,无转换的占66.7%,抚育采伐时应考虑伐除这些被压木.

Ana lysis on Cla ssif ied Stem Growing Character isticsof L a rix gm e lin ii Na tura l Forest

This paper expounded the growing characteristics of L a rix gm elin ii classified stem ( dom inant stem,average stem, overtopped stem) and analyzed the relation between the growing characteristics of classified stemand its stand factors and locality factors by setting p lots and making trunk analysis. The results of this study indicated that L. gm elin iiwould transform each other at the different age and its transformation rate was 38. 9%, where the average stem was 50%, and the dom inating stem and overtopped stem were all 33. 3%. The transformation rates of classified stem from dom inant stem to average stem and from average stem to overtopped stemwere highest, the opposition was low. However, the transformation rate from dom inant stem to overtopped stemand from overtopped stem to dom inant stem were the lowest. The interconversion of classified stem would increase as the stand density and the rate of L. gm elin ii was going up. The altitude that classified stem mainlyconcentrated was less than 1 000 m, slope was less than 25°, aspect was south slope, position was at m iddleand lower, soil dep th less than 17 cm. The rate of no interconversion was 66. 7% among overtopped stem. Itshould cut the overtopped stem as intermediate cutting.