Trade-offs among transport, support, and storage in xylem from shrubs in a semiarid chaparral environment tested with structural equation modeling
R. Brandon Pratt, Anna L. Jacobsen, Marta I. Percolla, Mark E. De Guzman, Courtney A. Traugh, Michael F. Tobin
Abstract
Significance Plant vascular systems play a central role in global water and carbon cycles and drought resistance. These vascular systems perform multiple functions that affect the fitness of plants, and trade-offs are present among these functions. Some trade-offs are well established, but studies have not examined the full suite of functions of these complex systems. Here, we used a powerful multivariate method, structural equation modeling, to test hypotheses about the trade-offs that govern this vital and globally important tissue. We show that xylem traits are broadly governed by trade-offs related to transport, mechanical support, and storage, which are rooted in cellular structure, and that the level of dehydration experienced by plants in the field exerts a strong influence over these relationships.