Source: Geophysical Research Letters
Understanding of root water uptake supporting water release into the atmosphere (known as transpiration) by plants has remained elusive due to the difficulty of studying root systems. However, the problem is important since climate change is expected to increase transpiration while reducing precipitation in many regions, causing a shortage of plant available water.
A common assumption used by ecologists and hydrologists is that root water uptake and access to groundwater is dictated either by plant gross similarities (for example, such as needle leaf vs broadleaf; temperate species vs. tropical species) or by their environment (for example landscape position that determines proximity to groundwater).
Knighton et al.  used a global analysis of root traits and signatures of water in plant tissues to conclude that evolutionary proximity of species determines root water uptake strategies. While so far there is little data from tropical forests with high diversity, this research suggests that that the wealth of information on species evolutionary proximities can be used to “map” root water uptake strategies for yet unstudied species.
Citation: Knighton, J., Fricke, E., Evaristo, J., de Boer, H. J., & Wassen, M. J. . Phylogenetic underpinning of groundwater use by trees. Geophysical Research Letters, 48, e2021GL093858. https://doi.org/10.1029/2021GL093858
―Valeriy Ivanov, Editor, Geophysical Research Letters