广西灌阳县天然阔叶混交林林分空间结构动态分析

该研究以灌阳县天然阔叶混交林为研究对象,通过对灌阳县天然阔叶混交林2005年和2010年2期森林清查数据对比,结合混交度、角尺度、大小比数这3个林分空间结构参数来说明5年期间该地天然阔叶混交林林分结构的变化及特点.分析发现,该地天然阔叶混交林混交度指数呈增大趋势,2期数据林分混交度值波动明显,总体上由弱度混交向中度混交转变.角尺度参数变化较稳定,林木空间分布多为团状分布状态,随林龄增大,其平均角尺度多有降低趋势,林分结构有向随机分布演变的趋势.该地林分在胸径生长大小上的分布状态均为中庸状态,各样地大小比数值波动不大,荷木在胸径生长大小上占据较大优势,主要分布的栎类2010年在胸径生长上的优势有所增加,也均处在中庸分布.总体来说,灌阳县天然阔叶混交林林分有向稳定森林群落发展的趋势,其空间结构还有待进一步优化.

Dynamic Analysis of Stand Spatial Structure of a Natural Broad-leaved Mixed Forest in Guanyang County,Guangxi Province

Taking the natural broad-leaved mixed forests in Guanyang County as the object of research,through comparison research on the survey data of natural broad-leaved mixed forest in 2005 and 2010,combined with three stand spatial structure parameters,such as the mingling intensity （M）,uniform angle index （W） and neighborhood comparison （U）,the changes and characteristics of the stand structure during the five years was elaborated.It was found that the mixed index showed a trend of increasing and two phase data of mixed degree fluctuated obviously.On the whole,the change was from the weak degree to moderate.The angle index changed very little,and the pattern of individual tree horizontal distribution was much as cluster distribution,with the increase of forest age,the avcrage of the angle index got down,there was a trend of the forest stand structure to random distribution.The situation of the DBH size of the natural broad-leaved mixed forests is most in medium state.The fluctuation of neighborhood comparison of all plots is gentle.Growth of Schima superba DBH is an advantage obviously,the DBH growth advantage of the mainly distributed Quereus L increased in 2010,also all in medium state.In general,the natural broad-leaved mixed forest in Guanyang County has a development trend to stable forest community,its spatial structure remains to be further optimized.