不同密度水曲柳人工林细根生物量对邻近树木胸径和距离的响应  

Responses of Fine Root Biomass to Diameters of and Distances to the Neighboring Trees of Fraxinus mandschurica Plantation with Different Stocking Densities

作　　者：刘悦[1] 谢玲芝 张彦东[1] 王政权[1] 谷加存[1] Liu Yue;Xie Lingzhi;Zhang Yandong;Wang Zhengquan;Gu Jiacun(Key Laboratory of Sustainable Forest Ecosystem of Management of Ministry of Education School of Forestry,Northeast Forestry University,Harbin 150040;Management Station for Fast-Growing and High-Yield Plantation Base of Guangxi Zhuang Autonomous Region,Nanning 530028)

机构地区：[1]东北林业大学林学院森林生态系统可持续经营教育部重点实验室,哈尔滨150040 [2]广西壮族自治区速生丰产林基地管理站,南宁530028

出　　处：《林业科学》2021年第10期15-22,共8页Scientia Silvae Sinicae

基　　金：国家重点研发计划项目(2017YFD0600605);中央高校基本科研业务费专项资金(2572020DR05)。

摘　　要：【目的】研究不同密度水曲柳人工林细根生物量对邻近树木胸径和距离的响应,为制定合理的水曲柳根系取样方案提供理论依据。【方法】在4种林分密度(Ⅰ:3572株·hm^(-2),Ⅱ:3128株·hm^(-2),Ⅲ:2215株·hm^(-2),Ⅳ:1468株·hm^(-2))的水曲柳人工林内,随机布点取样,测定0~10、10~20和20~30 cm土层吸收根(直径≤0.05 mm)和细根(直径≤2.0 mm)生物量及0~30 cm土层的吸收根总生物量和细根总生物量,并记录距取样点最近的1株和4株树的距离及胸径。采用线性回归分析,检验细根生物量与邻近树木距离和胸径的关系。【结果】0~30 cm土层吸收根和细根总生物量受林分密度影响显著,二者均在密度最小林分中最大;从林分密度Ⅰ~Ⅳ,吸收根占细根生物量的比例分别为61.6%、54.3%、52.9%和63.4%;在所有林分中,50%以上的细根和吸收根生物量分布在0~10 cm土层;在4种密度林分中,吸收根和细根总生物量与最近1株或4株树的距离均相关性不显著(P>0.05),仅有密度Ⅲ林分10~20 cm土层细根生物量与最近4株树的平均距离显著正相关(P<0.05);与细根总生物量相比,0~30 cm土层吸收根总生物量与邻近树木胸径之间呈现出更普遍的相关,但相关性显著水平与林分密度有关;密度Ⅰ林分吸收根和细根生物量均与最近1株树胸径显著正相关(均R^(2)>0.19),而密度Ⅱ林分吸收根和细根生物量均与最近4株树的平均胸径显著正相关(均R^(2)>0.21);密度Ⅲ林分中吸收根生物量与最近1株或4株树的胸径均显著相关(均R^(2)>0.16);而密度Ⅳ林分中吸收根和细根生物量与邻近树木胸径均不显著相关;在调查的3个土层中,细根和吸收根生物量与邻近树木胸径的相关性主要出现在0~10 cm土层,并呈现出与0~30 cm土层细根总生物量相似的规律。【结论】基于对不同密度水曲柳人工林细根生物量的研究结果,认为可在东北林区不同密度水曲柳人工林内灵活设【Objective】The main purpose of this study is to investigate the effects of distances to and diameters at breast height(DBH)of neighboring trees on fine root biomass with different stocking densities,and to reveal the main factors affecting root biomass,for providing a theoretical basis for formulating a reasonable root sampling plan.【Method】In Fraxinus mandschurica plantations with four stocking densities(TreatmentⅠtoⅣ:3572,3128,2215 and 1468 hm^(-2),respectively),we employed the method of random sampling to estimate the biomass respectively of absorptive roots(diameter≤0.5 mm)and fine roots(diameter≤2.0 mm)in soil layers of 0-10,10-20,and 20-30 cm and the totals of all soil layers,and measured the distance to and the DBH of the tree closest to the sampling point and four nearest neighbor trees.Linear regression analysis was used to examine the relationship between root biomass and the distance to and the DBH of the neighbor trees.【Result】The total biomass of absorptive and fine roots(0-30 cm soil depth)significantly varied with stocking density,both of which showing the maximum in the stand with the lowest stocking density.From stocking densityⅠtoⅣ,the proportions of biomass of absorptive roots in fine roots were 61.6%,54.3%,52.9%,and 63.4%,respectively.In all stands,more than 50%biomass of the fine roots and absorptive roots are distributed in the soil layer of 0-10 cm.In all the four stocking densities,there were no significant correlations between the total absorptive root or fine root biomass and the distance from the sampling point to the nearest one or four trees(P>0.05),except for the significantly positive correlation(P<0.05)between fine root biomass in 10-20 cm soil layer and the mean DBH of the nearest four trees in the treatmentⅢ.Compared with the total fine root biomass,the total absorptive root biomass showed a more general correlation with the DBH of neighbor trees,but the significance level of the correlation was related to the specific stocking densities.Both absorptive

关 键 词：细根 吸收根 水曲柳 林分密度 根生物量 

分 类 号：S792.41[农业科学—林木遗传育种]