林下植被对胡桃楸人工林细根生物量和形态特征的影响  

Effects of understory vegetation on the fine root biomass and morphological characteristics in Juglans mandshurica plantation

作　　者：郭超 王东男[1,2] 张硕 汲昌昊 谷加存[1,2] GUO Chao;WANG Dongnan;ZHANG Shuo;JI Changhao;GU Jiacun(School of Forestry,Northeast Forestry University,Harbin 150040,Heilongjiang,China;Ministry of Education Key Laboratory of Sustainable Forest Ecosystem Management,Northeast Forestry University,Harbin 150040,Heilongjiang,China)

机构地区：[1]东北林业大学林学院,黑龙江哈尔滨150040 [2]东北林业大学森林生态系统可持续经营教育部重点实验室,黑龙江哈尔滨150040

出　　处：《中南林业科技大学学报》2025年第1期82-89,101,共9页Journal of Central South University of Forestry & Technology

基　　金：国家自然科学基金项目(32071749)。

摘　　要：【目的】揭示不同林下植被覆盖对胡桃楸人工林细根形态和生物量的影响,为该地区胡桃楸人工林林下植被的科学管理提供理论参考。【方法】以黑龙江省帽儿山地区胡桃楸人工林为研究对象,测定了不同林下植被覆盖下胡桃楸树高和胸径的生长,采用土钻法研究了土壤表层(0~10 cm)和亚表层(10~20 cm)的胡桃楸吸收根(1~3级根)和运输根(4~5级根)的形态和生物量特征,同时测定了灌木和草本植物的根系生物量并分析其对胡桃楸根系生物量的影响。【结果】随着林下植被覆盖程度的增加,胡桃楸平均树高和胸径呈先升高后降低的趋势。林下植被增加导致土壤表层胡桃楸吸收根直径变细,比根长变大,而土壤亚表层仅根组织密度增大;胡桃楸运输根直径和比根长在两个土层均呈先增加后降低的趋势,而根组织密度没有显著差异。胡桃楸土壤表层和亚表层吸收根生物量均随林下植被增加先升高后降低,运输根生物量在土壤表层则呈现“N”形变化,而亚表层则先降低后升高;灌木吸收根和运输根生物量变化趋势较为复杂,而草本植物根系生物量则呈明显降低趋势。相关分析表明,胡桃楸根系生物量与林下植被根系生物量的相关性较弱,仅部分受灌木根系生物量的影响,而与草本根系生物量无显著相关性。【结论】胡桃楸细根形态和生物量分布受林下植被覆盖的影响,但是影响程度与根系功能群和土壤层次有关,保留一定程度的林下植被(35%<灌木盖度<46%)能够同时促进胡桃楸林分地上和地下的生长。【Objective】Revealing the impact of different understory vegetation covers on the morphology and biomass of fine roots in Juglans mandshurica plantation to provide theoretical references for scientific management of understory vegetation in J.mandshurica plantation.【Method】This study investigated the growth of tree height and diameter at breast height(DBH)of J.mandshurica plantation in the Maoershan area of Heilongjiang Province,China,under different understory coverages.The morphological characteristics and biomass of absorptive roots(the 1st-3rd orders)and transport roots(the 4th-5th orders)of J.mandshurica in the surface soil layer(0-10 cm)and subsurface soil layer(10-20 cm)were studied using soil core method.Additionally,root biomasses of shrubs and herbaceous plants as well as their impacts on the root biomass of J.mandshurica were also examined.【Result】As the coverage of understory vegetation increases,there is a trend of initially increasing and then decreasing average tree height and diameter at breast height(DBH)in J.mandshurica forests.The increase in understory vegetation leaded to a decrease in the diameter of absorptive roots of J.mandshurica in the surface soil layer,while specific root length increased.In the subsurface soil layer,only root tissue density increased.The diameter and specific root length of transport roots of J.mandshurica showed a trend of initially increasing and then decreasing in both soil layers.However,there was no significant difference in root tissue density.The biomass of absorptive roots of J.mandshurica in both the surface and subsurface soil layer of increased initially and then decreased with the increase of understory vegetation.On the other hand,the biomass of transport roots showed an“N”-shape change in the surface soil layer,while initially decreasing and then increasing in the subsurface soil layer.The variations of biomass of shrub absorptive-and transport roots were relatively complex,whereas root biomass of herbaceous plants showed a decreasing tre

关 键 词：人工林 林下植被 细根生物量 细根形态 森林经营 

分 类 号：S725.7[农业科学—林木遗传育种]