Editorial: Understanding forest ecosystems: the use of stable isotopes and physiological measurements

Understanding Forest Ecosystems: The Use of Stable Isotopes and Physiological Measurements 12 Forest ecosystems are complex and dynamic and can be challenging to comprehensively understand. 13 Measurements of forest physiology and stable isotopes can provide unique perspectives into forest 14 functions, often revealing mechanisms driving observed trends. For example, predawn water 15 potential can provide information about plant-available water to help explain variability in tree 16 drought resistance. ). In the tropics, an evaluation of hardwood tree species found that upland species 60 had relatively low sensitivity to temperature, low flexibility in nitrogen acquisition, and high root-to-61 shoot ratios (Ramesh et al.). Finally, a suite of physiological measurements found that strategies for 62 coping with summer water stress differed among coexisting hardwood species and between juvenile 63 and adult trees (Bryant et al.). This collective body of work demonstrates that while measurements of 64 tree physiology and stable isotope ecology can be time consuming, expensive, and require specialized 65 expertise, they can uncover important and unique insights into forest dynamics that bring a 66 mechanistic lens to forest ecology.