Depth of nutrient uptake by deep-rooted plants is regulated by water availability
Abstract
The capacity of some plants to access water and nutrients at depths greater than one meter is a critical functional trait that confers resistance to drought and impacts both belowground and shallow soil processes. Here, we report water and strontium isotopic data from an alpine meadow transect showing the correlation between water and nutrient acquisition depths. The isotopic compositions of Sr ( 87 Sr/ 86 Sr ratio) and water in rock and soil, and in plant leaf tissues, reveal that deeper-rooted plants acquire a higher proportion of water, Sr, and cation nutrients that are derived from the saprolite, a zone of silicate weathering, than shallow-rooted grass. A three-decade dendrochemical record reveals that reductions of wet precipitation drive deep-rooted plants to acquire cation nutrients from deeper saprolite or bedrock regions. Thus, the depth of cation nutrient acquisition by deep-rooted plant species at this site is tightly coupled with, and likely determined by, water availability in soil, saprolite, and bedrock. The enhanced uptake of cations as well as water from deeper saprolite zones could impact the rate of bedrock weathering and watershed chemistry during drought.
Article Details
Journal Info
Proceedings of the National Academy of Sciences
National Academy of Sciences
Authors (16)
Langlang Li
Department of Earth and Planetary Science, University of California
John N. Christensen
Earth and Environmental Science Area, Lawrence Berkeley National Laboratory
Markus Bill
Earth and Environmental Science Area, Lawrence Berkeley National Laboratory
Wenming Dong
Earth and Environmental Science Area, Lawrence Berkeley National Laboratory
Yuxin Wu
Earth and Environmental Science Area, Lawrence Berkeley National Laboratory
Curtis Beutler
Earth and Environmental Science Area, Lawrence Berkeley National Laboratory
Matthias Sprenger
Earth and Environmental Science Area, Lawrence Berkeley National Laboratory
Brian W. Gulick
Department of Geosciences, Stony Brook University
Sharon E. Bone
Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory
Boris Faybishenko
Earth and Environmental Science Area, Lawrence Berkeley National Laboratory
John Sanders
Department of Environmental Science, Policy and Management, University of California
Chunwei Chou
Earth and Environmental Science Area, Lawrence Berkeley National Laboratory
Amanda Henderson
Rocky Mountain Biological Laboratory
Nicholas J. Bouskill
Earth and Environmental Science Area, Lawrence Berkeley National Laboratory
Kenneth H. Williams
Earth and Environmental Science Area, Lawrence Berkeley National Laboratory
Benjamin Gilbert