冀北山地落叶松四种典型林分的结构研究

Spatial structure study of four typical larix forests in northern Hebei province

对冀北山地落叶松四种典型林分的结构进行了研究,结果表明:(1)在树种组成复杂程度上,杉落针阔混交林>落阔混交林>落桦混交林>落叶松纯林,而且杉落针阔混交林的树种组成比其他三个林分更加合理,结构更加稳定,在空间利用上也更加充分;(2)在水平结构上各个树种直径大小分布上,均匀程度比较:杉落针阔混交林>落阔混交林>落桦混交林>落叶松纯林,除了杉落针阔混交林为均匀分布,其他都比较接近团状分布;(3)在垂直结构上,分层情况比较:杉落针阔混交林、落阔混交林>落桦混交林>落叶松纯林,其中杉落针阔混交林和落阔混交林分层比较明显,而落桦混交林与落叶松纯林无明显分层;(4)在林分空间结构格局上,从角尺度来说,林分D的分布是随机分布,其他为团状分布;从大小比数来说,处于优势状态林分的百分比为:D>C>B;从混交度来说,落桦混交林属于弱度混交,落阔混交林属于强度混交,杉落针阔混交林属于极强度混交。

The spatial structure characteristics of four typical larch forest structure were investigated in northern Hebei province. The results show that （1） the sequencing of complexity of the four stands species composition from big to small was as follows： fir, drop, needles, broadleaved mixed forest 〉 drop and broad mixed forest 〉 drop and birch mixed forest 〉 pure larch forest, the mixed forest of fir, drop, needles, broadleaved was more reasonable than the other three stands, the structure was more stable, and more fully utilized in the space use; （2） from the view of horizontal structure, the sequencing of uniformity of each tree diameter size distribution was as follows： fir, drop, needles, broadleaved mixed forest 〉 drop and broad mixed forest 〉 drop and birch mixed forest 〉 pure larch forest, except the fir, drop, needles, broadleaved mixed forest which was even distribution, other three forest forms were close to slug distribution; （3） in the vertical structure, the sequencing of stratification degree was as follows： fir, drop, needles, broadleaved mixed forest 〉 drop and broad mixed forest 〉 drop and birch mixed forest 〉 pure larch forest, first two types showed obvious quantizing structure, while the later two showed no significant stratification; （4） in the pattern of stand space structure, from the perspective of the angular scales, the distribution of stand D was randomly distributed, the others were group-like distribution; from neighborhood comparison, the sequencing of percentage of the advantages state stands was as foloows： D 〉 C 〉 B; from mingling, the drop and birch mixed forest belongs to weak-mixed, drop and broad mixed forest belongs to strength mixed, fir, drop, needles, broadleaved mixed forest belongs to extreme intensity mixed forest.