林分因子对云顶山不同人工林林下植物多样性的影响

Effects of Stand Factors on Understory Species Diversity of Different Plantations in Yunding Mountain

该研究采用典型抽样法,以成都云顶山5种人工林——柏木-枫杨林(BF)、银杏-楠木林(YN)、光皮梾木-香樟林(GZ)、枫杨-桤木林(FQ)、柏木林(CB)为研究对象,分析不同人工林的林下植物组成与多样性特征,并确定影响林下植物多样性的主导林分因子,为当地人工林经营管理提供理论依据。结果表明:(1)研究区共记录林下植物168种,隶属于62科130属;5种人工林灌木层与草本层的科属种数均以GZ最多。(2)5种不同人工林灌木层与草本层的优势种数分别为7、4、7、6、4种和5、4、9、9、10种,数量都较少。(3)5种人工林的Shannon-Wiener多样性指数(H)、Simpson优势度指数(H′)、物种丰富度指数(D)、Pielou均匀度指数(J sw)均基本表现为草本层>灌木层,BF、GZ灌木层的D略高;灌木层的H、H′、D值均以GZ最大,但不同人工林的J sw差异不显著;草本层的H、H′、D、J sw均基本呈现CB>FQ>GZ>BF>YN趋势,GZ的D值略高于FQ。(4)6个林分因子对灌木层4个物种多样性指数的影响均无显著差异;林分平均树高、平均枝下高、平均胸径、平均冠幅和林分密度是影响草本层H、D的主要因子,但各林分因子对草本层H′、J sw的影响差异不显著。研究认为,林分结构对林下草本层物种多样性的影响更大,平均树高、平均枝下高、平均胸径、平均冠幅、林分密度对草本层多样性有显著影响。

We investigated the understory species composition and diversity and determined the dominant stand factors affecting the understory species diversity using typical sampling method in five plantations(BF:Cupressus funebris-Pterocarya stenoptera forest;YN:Ginkgo biloba-Phoebe zhennan forest;GZ:Swida wilsoniana-Cinnamomum camphora forest;FQ:Pterocarya stenoptera-Alnus cremastogyne forest;CB:Cupressus funebris forest)in Yunding Mountain,Chengdu,to provide scientific basis for local plantation management.The results showed that:(1)a total of 168 understory plants were recorded,belonging to 62 families and 130 genera.The number of families,genera and species in the shrub layer and herb layer of five plantations was the greatest in the GZ.(2)The number of dominant species in five different plantation shrub layer was 7,4,7,6,4,and the number of herb layer was 5,4,9,9,10,all of which were small.(3)The Shannon-Wiener diversity index(H),Simpson dominance index(H′),Richness index(D),Pielou evenness index(J sw)of five plantations were all expressed as:the herb layer>the shrub layer,the D of the BF and GZ was slightly higher in the shrub layer.The H,H′,and D of the shrub layer were the highest in the GZ,and there were no significant differences in the J sw of the shrub layer among different plantations.The H,D and J SW of the herb layer were sized as the CB,FQ,GZ,BF and YN,but the D of the GZ was slightly higher than FQ.(4)There were no significant differences in the effects of six stand factors on the four species diversity indexes in the shrub layer.The main stand factors affecting the D and H of the herb layer were average tree height,average branch height,average diameter at breast height,average crown and stand density.Stand factors had no effects on the H′and J SW in the herb layer.Research suggested that,the effects of stand structure on species diversity of the herb layer were more significant.Average tree height,average branch height,average diameter at breast height,average crown width and stand density had significant effects on the diversity of the herb layer.