摘要
利用微根管技术探讨细根径级、序级、出生季节、土层和林龄对福建南平18年生和90年生杉木人工林细根寿命的影响。杉木林细根中值寿命随径级增大而延长,18年生杉木人工林直径d≤0.3 mm、0.3<d≤0.6 mm、0.6<d≤1.0 mm和d>1.0 mm的细根中值寿命分别为(125±47)d、(158±16)d、(248±18)d和(272±53)d;90年生杉木人工林直径d≤0.3 mm和0.3<d≤0.6 mm的中值寿命分别为(95±20)d和(200±17)d,而0.6<d≤1.0 mm和d>1.0 mm的细根在观测期结束时,其累积存活率仍高于50%。18年生和90年生杉木高序级细根累积存活率都显著高于一级根,一级细根中值寿命分别为(180±13)d和(200±18)d,而高级根在观测期结束时,其累积存活率仍大于50%。18年生杉木秋季出生的细根累积存活率显著高于夏季,90年生杉木冬季和秋季出生的细根累积存活率均极显著高于春季和夏季。18年生杉木冬季、秋季、春季、夏季出生细根的中值寿命分别为(216±16)d、(248±12)d、(172±6)d和125 d;90年生杉木秋季、春季、夏季出生细根中值寿命分别为383 d、(127±23)d和(106±19)d,而冬季出生的细根在观测期结束时累积存活率仍在50%以上。90年生杉木细根累积存活率随土壤深度增加而显著增加,土层深度0<D≤20 cm和20<D≤40 cm细根中值寿命分别为(156±14)d和(241±24)d,而40<D≤60cm土层细根寿命在观测期结束时累积存活率仍在50%以上;18年生不同土层细根累积存活率则均无显著差异,中值寿命分别为(187±19)d、(216±28)d和(120±47)d。不同林龄相同径级或序级细根的存活曲线均无显著差异;除了夏季外,不同季节出生的同生根群存活率曲线在不同林龄之间均具有显著差异;0<D≤20cm、20<D≤40cm土层细根存活曲线在不同林龄间无显著差异,但40<D≤60cm土层的细根存活曲线在不同林龄间则存在显著差异。
The influences of root diameters,branch orders,seasons of birth,soil depths and stand ages on fine root lifespans were studied using minirhizotrons in the 18-and 90-year-old Chinese fir（Cunninghamia lanceolata） plantations in Nanping,Fujian Province.The median lifespans（ML） of fine roots increased with the diameter,with the corresponding ML of（125±47） d,（158±16） d,（248±18） d,and（272±53） d for roots of ≤0.3 mm,0.3-0.6 mm,0.6-1.0 mm,and 1.0 mm in the younger stand,and of（95±20） and（200±17） d for roots of ≤0.3 mm and 0.3-0.6 mm in the old-growth stand.Roots of 0.6-1.0 mm and 1.0 mm in the old-growth stand had the accumulative survival rates over 50% at the end of the experiment.The accumulative survival rates of high order roots were significantly higher than those of the first order roots in both stands,with ML of（180±13） d and（200±18） d respectively for the first order roots and with the accumulative survival rates over than 50% for the high order roots when the experiment was over.In the younger stand,roots born in the autumn had significantly higher accumulative survival rates than those born in the summer,while those born in the winter and autumn had significantly higher accumulative survival rates than those born in the spring and summer in the old-growth stand.The ML was（216±16） d,（248±12） d,（172±6） d,and 125 d respectively for roots born in the winter,autumn,spring and summer in the younger stand,and was 383 d,（127±23） d,and（106±19） d respectively for those born in the autumn,spring and summer in the old-growth stand.Roots born in the winter in the old-growth stand had an accumulative survival rate over 50% at the end of the experiment.The accumulative survival rates increased significantly with soil depths for roots of the old-growth stand,with ML of（156±14） d and（241±24） d respectively for the 0-20 cm and 20-40 cm depths and an accumulative survival rate over 50% for the 40-60 cm depth at the end of the experiment.There was no significant difference in the accumulative survival rates for roots of the younger stand among soil depths,with ML of（187±19）d,（216±28） d,and（120±47） d,respectively.There was no significant difference in the survival curves between the stands for roots with the same diameter class,root order,season of birth or soil depth,except those born in the summer and those inhabited the 40-60 cm depth for which significant differences between stands were found.
出处
《生态学报》
CAS
CSCD
北大核心
2011年第4期1130-1138,共9页
Acta Ecologica Sinica
基金
国家自然科学基金项目(30972347)
福建省自然科学基金项目(2008J0124)
关键词
细根
寿命
杉木
微根管
生存分析
fine root
lifespan
Chinese fir
minirhizotron
survival analysis
作者简介
通讯作者Corresponding author．E-mail：gshuichen@163．com
