7.3 Conclusion
To mitigate hydraulic damage, many plant species adhere to a strict coordination between regulation of ΨL and vulnerability to embolism. However, we found that the ΨL behavior ofQ. alba was not buffered by embolism resistant tissues to the same extent as co-occurring L. tulipifera and A. saccharumacross ten eastern US forests sites. These results highlight that important and abundant eastern US forest species have drought-response traits that are coordinated in a fundamentally different way than popular modeling frameworks (Naudts et al. , 2015; Sperry & Love, 2015; Kennedy et al., 2019; Mirfenderesgi et al ., 2019). Moreover, we found that Q. alba sustains gas exchange at the cost of operating with damaging water potential gradients and low Ψsafety such that Quercus dominated forests may be vulnerable to shifting drought regimes (Ficklin & Novick, 2017). Ultimately, our understanding of plant-water relations may be improved by further investigation into physiological mechanisms which allow plants to tolerate or recover from xylem dysfunction. Such mechanisms may be particularly important in temperate regions, where generally moisture-abundant conditions may facilitate embolism repair through regrowth following drought.