7.3 Conclusion
To mitigate hydraulic damage, many plant species adhere to a strict coordination between regulation of ΨL and vulnerability to embolism. For common deciduous tree species growing in temperate eastern US forests, we found that the extent of ΨLregulation was not linked to vulnerability of xylem embolism. Specifically, Q. alba, an anisohydric species, possessed xylem more vulnerable to embolism than the more isohydric L. tulipiferaand A. saccharum . Moreover, this behavior was generally unaffected by spatio-temporal factors such that coordination among traits were conserved at the species-level. These findings suggest species growing in temperate ecosystems have drought-response traits that are coordinated in a fundamentally different ways than arid climate vegetation. Ultimately, our understanding of plant-water relations may be improved by further investigation into mechanisms which allow plants to tolerate or recover from xylem dysfunction.
8. Acknowledgements
We thank D. Tyler Roman, Matthew K. Wenzel, Kathryn O. Shay, Mike P. Voyles, and Daniel C. Ishmael for assistance with data collection. We acknowledge support from the USDA Forest Service, Southern Research Station, US Department of Energy, through the Terrestrial Ecosystem Science Program and the AmeriFlux Management Project, the National Science Foundation Division of Environmental Biology (grant DEB-1552747 and DEB-1637522) the Integrative Organismal System (IOS-1754893), and the USDA Agriculture and Food Research Initiative (grant 2017‐67013‐26191 and 2012‐67019‐19484). JDW acknowledges support for the MOFLUX (US-MOz) site from the U.S. Department of Energy, Office of Science, Office of Biological and Environmental Research Program, through Oak Ridge National Laboratory’s Terrestrial Ecosystem Science Focus Area; ORNL is managed by UT-Battelle, LLC, for the U.S. DOE under contract DE-AC05-00OR22725. The authors declare no conflicts of interest.