Ecological and physiological implications of vascular structure and function in oaks

Abstract

A plant's ability to transport water is one of its most critical physiological functions. Indeed, plant vasculature has been described as the ”backbone” supporting the productivity of terrestrial ecosystems. In my dissertation research I have investigated connections between plant hydraulics and ecological function at at two scales: first, the role that whole-plant water movement plays in how three oak species partition a hydrologic gradient, and second, the ways leaf level vascular structure can offer insights into overall plant function when studied through a framework informed by network theory. I will discuss results from a study testing how differences in water-use traits might permit three oak species to co-exist in a small geographic area, where we have shown that whole-plant hydraulic conductance is one of several characteristics that explains their local distribution. I will then introduce "LeafGrapher," a software tool I have developed to apply a network analysis approach to leaf venation architecture. Finally I demonstrate the validity of these metrics by looking at the relationships between these network-derived venation traits and known plant functional traits measured on North American and European oaks in a common garden. This work gives us some novel insights into the role plant vascular biology plays in a broader eco-physiological framework.