怀化市鹤城区针阔混交林林分结构研究

以怀化市鹤城区针阔混交林为研究对象,选择具有代表性的11块20 m×20 m标准地,进行树种组成结构分析,并利用Weibull分布函数开展直径分布研究。结果表明:(1)标准地内乔木层阔叶树以檫木、枫香、木荷为主,针叶树以杉木、马尾松、柏木为主。林木总蓄积量比重值位于前5位的树种是:杉木、枫香、马尾松、楠木、檫木,分别占总蓄积量的18.52%、18.36%、18.13%、12.88%、12.70%。(2)林分直径结构分析表明,树木直径分布曲线均呈不规则单山峰状曲线,应用Weibull分布函数拟合反映直径分布,并进行x2检验,效果比较理想。(3)各标准地林分的混交度均值都大于0.7,各优势树种的平均混交度比较高,按从大到小排序为马尾松杉木木荷檫木苦槠白栎枫香楠木柏木。

The stand structure of coniferous and broad-leaved mixed forest in Hecheng District of Huaihua

Taken coniferous and broad-leaved mixed forest in Hecheng District of Huaihua City as the object,the 1 1 pieces of 20 m ×20 m standard plots were selected to study the tree species composition structure,and the diameter distri-bution was researched using Weibull distribution function. The results showed that,the dominant broadleaf trees in tree layer were Sassafras tzumu,Liquidambar formosana,Schima superba,and the dominant coniferous trees in tree layer were Cunninghamia lanceolata,Pinus massoniana and Cupressus funebris. The top 5 tree species of volume were C. lanceola-ta,L. formosana,P. massoniana,Phoebe zhennan and S. tzumu,which accounted for 18.52%,18.36%,18.13%, 12.88%and 12.70%to total volume,respectively. Diameter distribution analysis showed that the tree diameter distribu-tion curve was irregular single peak curve,the application of Weibull distribution function fitting could reflect the diameter distribution in this area,and the effect was ideal. In all plots,the average mingling degree of stand was higher than 0.7, and the average mingling degree of the dominant tree species was also quite high,in the order of P. massoniana >C.lanceolata >S. superba >S. tzumu >Castanopsis sclerophylla >Quercus fabri >L. formosana >P. zhennan >C.funebris.