摘要
为量化林分密度对马尾松人工林群落冠层结构及林下植被的影响,以广西壮族自治区横州市镇龙林场25年生马尾松不同造林密度试验林林分为研究对象,采用单因素方差分析、Pearson相关分析和冗余分析等方法探讨林分密度对马尾松生长情况、冠层结构以及林下草本多样性的影响.结果表明:林分造林密度在2500～6000株/hm2,随着密度增大,马尾松人工林群落冠层结构LAI先增大后不变,且在DS2(3300株/hm2)时逐渐稳定,林下散射辐射以及直射辐射在林分密度DS2光照适宜.马尾松人工林林下草本多样性Simpson指数、Shannon-Wiener指数、Pielou均匀度指数、Patrick指数对林分密度变化不明显,群落冠层结构林冠开度与林下草本多样性指数Shannon-Wien-er指数呈极显著负相关.因此,林分造林密度3300株/hm2下的马尾松人工林群落冠层结构较好,林下散射辐射以及直射辐射有利于林下草本多样性的维持,是马尾松人工林适宜的营林密度.
Abstract
To investigate the effects of stand density on the crown structure and understory vegetation of 25-year-old Pinus massoniana plantation,experimental plots with different planting densities were selected in Zhen-long Forest Farm,Hengzhou City,Guangxi Zhuang Autonomous Region.Single-factor analysis of variance(one-way ANOVA),Pearson correlation analysis,and redundancy analysis were employed to explore the influence of stand density on the growth,crown structure,and understory herbaceous diversity of P.massoniana.The results are as follows the stand density was in 2500 trees/ha-1-6000 trees/ha-1.With the increase of planting density,the canopy structure LAI of P.massoniana plantation community increased first and then remained unchanged,and gradually stabilized at DS2(3 300 trees/ha-1).The scattered radiation and direct radiation of understory illumina-tion were suitable for DS2.The understory herbaceous diversity indices,including the Simpson index,Shannon-Wiener index,Pielou evenness index,and Patrick index,showed no significant changes with variations in stand density in the P.massoniana plantation.However,there was a highly significant negative correlation between canopy openness of the community crown layer and the Shannon-Wiener diversity index of understory herb-aceous vegetation.In summary,the canopy structure of P.massoniana plantation community was better under the stand density of 3 300 trees/ha-1,and the scattered radiation and direct radiation under the forest were conducive to the maintenance of undergrowth vegetation diversity,which was the reasonable forest density of P.massoniana plantations.
基金项目
重点研发项目(十三五)(2017YFD0600303)
重点研发项目(十三五)(2017YFD060030202)
广西科技基地和人才专项(桂科AD19254004)
广西八桂学者专项(2019A026)
广西壮族自治区科技重大专项(桂AA17204087-4)
国家科技期刊平台
NSTL
万方数据