不同密度对杉木纯林径级结构及土壤地力的影响  

Effects of different densities on DBH structure and soil fertility of Chinese fir pure forest

作　　者：田海燕 徐清乾[2] TIAN Haiyan;XU Qingqian(Liuyang Forestry Bureau,Liuyang 410300,Hunan,China;Hunan Academy of Forestry,Changsha 410004,Hunan,China)

机构地区：[1]浏阳市林业局,湖南浏阳410300 [2]湖南省林业科学院,湖南长沙410004

出　　处：《湖南林业科技》2023年第3期96-101,共6页Hunan Forestry Science & Technology

基　　金：国家重点研发计划子课题(2021YFD2201302-2)。

摘　　要：在杉木纯林实施保留密度A(450株·hm^(-2))、B(675株·hm^(-2))、C(900株·hm^(-2))、D(1125株·hm^(-2))、E(1350株·hm^(-2))、CK(1950株·hm^(-2))的间伐试验,对26年生林分的径阶、径级结构及土壤地力指标进行分析。结果表明:含间伐木在内,6个保留密度林分的胸径均处于6~30径阶的13个径阶范围,5个间伐处理各径阶株数百分比均呈现“极高点左侧缓慢上升、右侧急剧下降”的非对称分布,极高点分别位于24、24、22、22、22径阶;CK呈基本对称分布,极高点位于18径阶。随着林分保留密度的增加,林分平均胸径,大径材株数占比,土壤有机质含量及细菌、放线菌、真菌的数量,均呈现先增高后下降趋势,且都以CK的最小或最少;林下植物种类、生物量及土壤含水率呈逐渐减少趋势;土壤容重呈逐渐增加趋势。综合杉木林分生长速度、质量及土壤地力,保留密度以1125株·hm^(-2)最为合适。The structure of diameter class,diameter structure,and soil fertility index of 26-year-old stand were analyzed by thinning test with different retention densities of A,B,C,D,E,and CK(450,675,900,1125,1350,1950 plants per hectare respectively)in a pure Chinese fir forest.The results were as follows:The diameters at breast height(DBH)of the six treatments were all in the range of 13 diameter classes from 6 cm to 30 cm including thinning trees.The percentage of plants in each diameter class of the five thinning treatments showed an asymmetric distribution of“rose slowly on the left side of the extremely high point and fell sharply on the right side”,with extremely high points located in 24,24,22,22,and 22 cm diameter class,respectively.The percentage of plant number of each diameter class of CK was basically symmetrical,with the extremely high point located in 18 cm diameter class.With the increase of stand retention density,the average DBH,the proportion of large-diameter trees,content of soil organic matter,and number of bacteria,actinomycetes and fungi all increased firstly and then decreased with CK being the smallest or the least,the undergrowth vegetation species,biomass and soil moisture content decreased gradually,while the soil bulk density increased gradually.Taking into consideration the growth rate,quality of Chinese fir stand,and soil fertility,the most suitable retention density was 1125 plants per hectare.

关 键 词：杉木 密度 径级结构 土壤理化性质 微生物数量 

分 类 号：S753.3[农业科学—森林经理学]