大兴安岭主要森林类型林分空间结构及最优树种组成

Quantitative Analysis of Forest Spatial Structure and Optimal Species Composition for the Main Forest Types in Daxing'anling,Northeast China

以2011—2012年大兴安岭的44块固定样地调查数据为基础,以常用的林分空间结构参数(角尺度、大小比、混交度、林分空间结构指数和林分空间结构距离)为切入点,对大兴安岭主要森林类型的林分空间结构特征及最优树种组成进行研究。结果表明:天然落叶松林、针叶混交林以及针阔混交林的林木水平分布格局均表现为随机分布,而白桦林则为明显的聚集分布;4种林型中树木的生长整体处于中庸状态,落叶松处于明显优势地位,其他伴生树种则处于不同程度受压状态;落叶松混交程度随着其优势程度的增加而降低,其他伴生树种则具有较高的混交度,整体上天然落叶松林、白桦林的树种空间隔离程度较低,而针叶混交林、针阔混交林的林分平均混交度相对较高;大兴安岭4种主要森林类型林分空间结构的优劣表现为针阔混交林>针叶混交林>天然落叶松林>天然白桦林;天然落叶松林最优的树种组成为8落,其次为7落。

Forest health management is one of the research hotspots at the present stage,and the key is to maintain and create the optimal forest spatial structure.The forest spatial structure （FSS） and optimal species composition were studied with the commonly-used forest spatial structure parameters （i.e.mingling,neighborhood comparison,neighborhood pattern,forest spatial structure index （FSSI）,and forest spatial structure distance （FSSD）） based on the data of 44 plots in Daxing＇ anling Mountains of northeast China,which were collected in the 2011 and 2012.The results showed that the horizontal distribution pattern of natural Larix gmelini （LG）,coniferous mixed （CM） and coniferous-broadleaved mixed （CBM） stands mainly followed the random distribution,and the Betula platyphylla （BP） natural forest followed the typical cluster distribution.The tree growth of the four forest types were moderate as a whole,in which L.gmelini was at the dominant position and the others species were squeezed with different degrees.And the mixed degree of L.gmelini was reduced with the increase of its dominance,the other species had a higher mixed degree of species.As a whole,the mixed degree of species for LG and BP forest were relative lower （0.20 and 0.07）,but the two mixed forest types were higher （0.45 and 0.56）.Significant difference of FSS was found among the four main forest types in study area,the order was CBM ＞ CM ＞ LG ＞ BP.From the viewpoint of maintaining and creating the optimal forest spatial structure,it was found that the proportion of L.gmelini accounted for 80％ of the whole forest was the optimal species composition for the LG forest.