Mountain forests are important ecosystems subject to extreme climate conditions. Soil buffers root systems against variations in the weather, but we know little of how climate affects tree root growth and mortality. Wang et al. installed rhizotrons in mountain forests at different altitudes and measured root growth and mortality every month for 4 years.
They find that root elongation is mostly driven by soil temperature between zero and 8°C and was lower in cold soils. At 2000 m, short-lived, fine roots were more numerous, compensating for the short growing season. Soil water had little effect on root growth or mortality.
Wang, Y., Kim, J. H., Mao, Z., Ramel, M., Pailler, F., Perez, J., … Stokes, A. (2018). Tree root dynamics in montane and sub-alpine mixed forest patches. Annals of Botany. https://doi.org/10.1093/aob/mcy021