密度调控对米老排中龄人工林生长的影响  

Effect of density regulation on growth of Mytilaria laosensis plantation with middle age

作　　者：唐继新[1,2] 贾宏炎[1] 王科 曾冀[1] 郑路[1] 王亚南[1] 杨保国[1] TANG Jixin;JIA Hongyan;WANG Ke;ZENG Ji;ZHENG Lu;WANG Yanan;YANG Baoguo(Experimental Center of Tropical Forestry,Chinese Academy of Forestry,Pingxiang 532600,China;Research Institute of Forest Resourees Information Techniques,CAF,Beijing 100091,China;Guangxi Forestry Inventory and Planning Institute,Nanning 530001,China)

机构地区：[1]中国林业科学研究院热带林业实验中心,广西凭祥532600 [2]中国林业科学研究院资源信息研究所,北京100091 [3]广西林业勘测设计院,广西南宁530001

出　　处：《南京林业大学学报（自然科学版）》2019年第1期45-53,共9页Journal of Nanjing Forestry University：Natural Sciences Edition

基　　金：全国森林经营科技支撑科研专项项目(1692017-1);广西自然科学基金项目(2016GXNSFBA380087)

摘　　要：【目的】密度是影响林分生产力的关键因素之一,分析密度调控对米老排中龄林生长的影响,进而为其间伐密度调控提供决策依据。【方法】以南亚热带中等立地两种不同密度调控的米老排中龄林为对象,按优势木、中等木、被压木的条件选取了28株标准木(每林分各14株),基于2 m区分段的中央断面积树干解析法和双侧t检验的统计分析法,对不同调控密度下米老排林分的平均木、优势木和林分蓄积等生长过程进行对比分析。【结果】米老排径向生长的缓慢期在第1～2年,速生期在第3～10年,衰减期在第14年后。树高的早期速生特性明显,连年生长量呈多峰状,速生期主要在第2～6年。平均木与优势木材积生长的缓慢期均在前6年,从第8年起均进入速生期;密度对平均木材积连年生长与林分数量成熟时间的影响显著,哨平试验林(在第12年经过生长伐1次,伐后林分最终密度为1 200株/hm2)数量成熟在第24年,而青山试验林(分别在第12年、第17年、第25年经过3次生长伐后,林分最终密度为520株/hm2)直至第34年仍未达到数量成熟。中弱度间伐(株数间伐强度<30%)对中龄林蓄积总生长量的影响不显著,对林分蓄积连年生长量短期有一定影响;强度间伐(株数间伐强度>30%)对中龄林蓄积总生长量与连年生长量的影响显著(P<0.05)。在第14年后,米老排树种的实验形数趋于稳定。【结论】林分密度调控在520～1 200株/hm2的范围内,密度调控措施对米老排平均木的胸径和材积的生长影响显著(P<0. 05),对林分树高和平均实验形数的影响不显著,对优势木的胸径与材积的短期生长影响显著(P<0. 05),对其长期生长的影响不显著,对减小林分径阶分化及提高大径木比例的作用明显。【Objective】Stand density regulation can promote the growth of trees,improve forest quality as well as forest stand structure,and play the key role in the technology of forest multi-function. Thus,reasonable stand density regulation can affect the achievement of a forest culture’s goals and influence the full extent of the forest for greater benefits. To obtain a reasonable thinning measure for mid-maturation Mytilaria laosensis plantations,it is important to ascertain the effects of density regulation on plantation growth. 【Method】Based on 28 analytic trees( 14 analytic trees in each stand),including dominant trees,medium trees,and pressed trees,the growth of dominant trees,mean trees,and stand volume in two mid-maturation Mytilaria laosensis plantations( Qingshan stand and Shaoping stand) with different density regulation in the south subtropical area of China were compared. Comparisons were made using the tree stem analytic method of the middle section in 2 m and Student ’ s t-test was conducted with data processing system software( DPS14.5). The Qingshan stand had an afforestation time in the spring of 1982,a planted density of 2 500 plants per hectare,and experienced one lighting cutting( in the 7th year) and three accretion cuttings( in the 12 th,17th,and 27 th year;the stem thinning intensity was between 21%-42%) after afforestation;after which the forest stand density was 520 plants per hectare. For the Shaoping stand,planting time was in the spring of 1984,afforestation density was 2 500 plants per hectare,and the stand experienced once lighting cutting( in the 7 th year) and one accretion cutting( in the 12 th year;the stem thinning intensity was 27%);after thinning the stand density was 1 200 plants per hectare.【Result】(1) The radial slow-growing period occurred during the first 1-2 years,and the fast-growing stage occurred at 3-10 years of age( annual increment of diameter at breast height( DBH) was during 0.72-2.45 cm),with attenuation starting at 14 years of age.(2) Tree height exhibi

关 键 词：米老排 密度调控 中龄林 人工林 平均木 优势木 生长 双侧t检验 

分 类 号：S725[农业科学—林木遗传育种]