Acknowledgments
We would like to thank Jeremiah Anderson, Kaitlyn Read, and Jun Tominaga for their help in the field, Mark Marsalis of the New Mexico State University Agricultural Center for allowing us to conduct research on their land, Todd Rosenstiel (Portland State University) for providingP. deltoides , David Weston (Oak Ridge National Lab) for providingP. trichocarpa , and Maria J. Thomas (ABQ BioPark Botanic Gardens) for allowing us to conduct research at the botanical gardens. This research was partially supported by a Fulbright Canada scholarship to JRS. JRS would also like to acknowledge scholarship support from the Natural Sciences and Engineering Research Council of Canada (NSERC). This work was also supported by funding to DTH through the NSF EPSCoR Program under Award # IIA-1301346 at the University of New Mexico. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the authors and do not necessarily reflect the views of the National Science Foundation. AR was supported by the Next-Generation Ecosystem Experiments (NGEE Arctic and NGEE Tropics) projects that are supported by the Office of Biological and Environmental Research in the Department of Energy, Office of Science, and through the United States Department of Energy contract No. DE-SC00112704 to Brookhaven National Laboratory.