中龄和老龄杉木人工林细根序级形态和呼吸特征

摘要

以福建省南平市王台镇溪后村安曹下19年生和91年生杉木人工林为研究对象，对其1～5级细根的形态及呼吸特征进行了比较研究。结果表明：2个林分细根直径、根长、组织密度随序级升高逐渐增大，比根长及比根呼吸随序级升高则减小；2个林分细根仅在4级根之间和5级根之间的直径以及5级根之间的比根呼吸具有显著差异（ P＜0.05）。方差分析表明林龄仅对细根直径有极显著影响（P＜0.01），对根长、比根长、组织密度及比根呼吸的影响均不显著；林龄和序级的交互作用对细根直径，比根长及比根呼吸有显著影响（P＜0.05， P＜0.01），对根长和组织密度的影响不显著；序级对两个林分细根直径、根长、比根长、组织密度及比根呼吸的影响均达到极显著水平（ P＜0.01）。回归分析表明2个林分细根直径、根长、比根长、组织密度及比根呼吸与序级之间具有三次函数，指数函数，或者幂函数关系。%Fine root morphology and respiration rates of the first to fifth root order were measured in a young (19-year-old) and an old (91-year-old) Chinese fir ( Cunninghamia lanceolata) plantation lo-cated at Wangtai Town , Nanping City , Fujian province .Our objectives were to determine how root morphology and respiration rates differ across root branch orders and between stand ages .Root diame-ter, length, and tissue density increased and specific root length ( SRL ) , specific root respiration ( SRR) decreased with increasing root order for both stands , while there was significant difference ( P<0.05) in the fourth and fifth order for the root diameter , and the fifth order for the specific root respira-tion between the young and the old Chinese fir .The ANOVA demonstrated that stand age had signifi-cant effect on root diameter ( P<0.01 ) , but had no significant effect on root length , SRL, tissue density , and SRR.The stand age ×root order interaction had significant effect on root diameter , SRL and SRR ( P<0.05 , P<0.01 ) , but had no significant effect on root length and tissue density;root order had significant effect on root diameter , length, SRL, tissue density, and SRR (P<0.01).For both stands, changes in root diameter, length, SRL, tissue density and SRR with root order can be fit-ted by the cubic , exponential , or power functions .