Author contributions
URR and JTAM. designed the study; U.R-R., J.T.A-M., and E.H-S. wrote the
manuscript; J.A.R-L and E.Y. provided expertise in geophysical methods
and isotopic analysis; U.R.-R., J.T.A.-M. and J.A.R-L. ran the field
experiments. U.R-R. and E.Y. executed the stable isotope analyses;
U.R-R., J.T.A-M., E.H-S., J.A.R-L, and E.Y. analyzed the data.