南京林业大学学报（自然科学版）2026，Vol.50Issue(1)：179-187,9.DOI:10.12302/j.issn.1000-2006.202407037
不同密度和水分管理下毛白杨人工林细根分布特征
Characteristics of fine root distribution in Populus tomentosa plantations under density and water management
摘要
Abstract
[Objective]This study investigated the distribution characteristics of fine roots in poplar(Populus tomentosa)plantations under different stand densities and water management regimes,aiming to optimize cultivation techniques for poplar plantations in the north China Plain.[Method]In 2021,we employed the soil core method to analyze fine root(＜2 mm in diameter)growth,morphological indices,and soil water content with the 6 m soil profile across five treatment combinations:FIhigh(high density+full drip irrigation),FIlow(low density+full drip irrigation),NIhigh(high density+rainfed),NIlow(low density+rainfed),and NImedium(medium density+rainfed).Stand densities were categorized as high(3 m × 3 m),medium(3 m × 6 m)and low(6 m × 6 m).The study assessed how density and irrigation(FI.full drip irrigation;NI.rainfed)influence fine root biomass distribution,vertical stratification,and horizontal extension.[Result]①In high-density stands,fine roots were uniformly distributed at varying distances from the tree base,whereas in medium-and low-density stands,fine root biomass decreased with increasing distance from the tree.②Across all treatments,fine root biomass declined with soil depth,with the peak distribution of P.tomentosa fine roots occurring in the[0,200]cm layer(108.15-450.74 g/m3).③Reduced planting density led to shallower fine root distribution.Under FI,fine roots were concentrated in upper soil layers,with the shallowest cumulative 50％fine root biomass density(RBD)observed in the low FI treatment(26.49 cm).④Under NI conditions,NIhigh exhibited the lowest mean RBD(58.16 g/m3)in the[0,600]cm profile but increased fine root growth in the(100,400]cm layer.NImedium enhanced deep root distribution and accelerated soil water depletion in deeper layers.Compared to NI,FI reduced RBD below 30 cm.⑤Under NI,density had no significant effect on fine root morphology.However,in high-density stands,FIhigh promoted stand growth in the(30,600]cm layer via efficient root traits:high specific root length(24.45-90.97 m/g),low tissue density(0.24-0.39 g/cm3),and small mean diameter(0.20-0.32 mm).[Conclusion]Fine roots of P.tomentosa exhibit a vertical distribution within[0,600]cm,decreasing with depth across all treatments.Reducing planting density shifts fine roots upward,decreasing deep-layer biomass.Under NI,high-density stands enhance root boundary density(RBD)in the(100,400]cm range,improving fine root surface area(RSA)and length density(RLD),mitigating underground competition.Medium-density stands under NI promote deep root growth,accelerating deep soil water use.Under FI,high-density stands optimize root plasticity rather than biomass expansion to improve water-use efficiency and growth.These findings support climate-resilient poplar plantation strategies that balance productivity and sustainability in semi-arid regions.关键词
毛白杨人工林/造林密度/滴灌充分灌溉/细根分布Key words
Populus tomentosa plantation/planting densities/drip irrigation with full irrigation/fine roots distribution分类
农业科技引用本文复制引用
周欧,古丽米热·依力哈木,祝维,王亚飞,贾黎明,席本野..不同密度和水分管理下毛白杨人工林细根分布特征[J].南京林业大学学报（自然科学版）,2026,50(1):179-187,9.基金项目
国家重点研发计划(2021YFD2201203). （2021YFD2201203）
