Young temperate tree species show different fine root acclimation capacity to growing season water availability.

BACKGROUND AND AIMS

Changes in water availability during the growing season are becoming more frequent due to climate change. Our study aimed to compare the fine-root acclimation capacity (plasticity) of six temperate tree species aged six years and exposed to high or low growing season soil water availability over five years.

METHODS

Root samples were collected from the five upper strata of mineral soil to a total soil depth of 30 cm in monoculture plots of Marsh., Marsh., K. Koch, L., (Moench) Voss and L. established at the International Diversity Experiment Network with Trees (IDENT) field experiment in Sault Ste. Marie, Ontario, Canada. Four replicates of each monoculture were subjected to high or low water availability treatments.

RESULTS

Absorptive fine root density increased by 67% for , and 90% for , under the high-water availability treatment at 0-5 cm soil depth. The two late successional, slower growing tree species, and showed higher plasticity in absorptive fine root biomass in the upper 5 cm of soil (PIv = 0.36 & 0.54 respectively), and lower plasticity in fine root depth over the entire 30 cm soil profile compared to the early successional, faster growing tree species and .

CONCLUSION

Temperate tree species show contrasting acclimation responses in absorptive fine root biomass and rooting depth to differences in water availability. Some of these responses vary with tree species successional status and seem to benefit both early and late successional tree species.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s11104-023-06377-w.