PS 20-65 - Effects of root diameter, branch order, season and soil depth on fine root life span in five temperate tree species

Wednesday, August 10, 2016
ESA Exhibit Hall, Ft Lauderdale Convention Center
Jiacun Gu1, Xiuxue Xia1, Zhengquan Wang1 and Timothy J. Fahey2, (1)School of Forestry, Northeast Forestry University, Harbin, China, (2)Department of Natural Resources, Cornell University, Ithaca, NY
Background/Question/Methods

Fine root life span depends on endogenous and exogenous factors, but few studies have quantified variation among tree species.  Here, we investigate how root life span is influenced by root diameter, branch order, season of birth, and soil depth in five temperate tree species in northeastern China. Minirhizotron approach was used to estimate root life span.  Cox proportional hazards regression analysis was employed to determine the impact of those four factors on root life span at species level.

Results/Conclusions

Root life span increases with root diameter and depth across all five species.  Roots born in spring often have shorter life span than those in summer and autumn.  The first two or three branch order roots within each species generally share similar life span, probably because they are similar in anatomical structure and physiological function.  Our results suggest that elucidating the relations between root life span and root anatomy, structure and environmental conditions might help understand patterns of root life span variation within and among tree species.