Evaluating Aspects of Water Economy and Photosynthetic Performance with Stable Isotopes from Water and Organic Matter

Abstract

This chapter focuses on stable isotopes as a tool for investigating aspects of water economy and photosynthetic performance of tropical forest plants. We discuss stable isotope ratios in water as an index of spatial and temporal patterns of soil water utilization, and stable carbon isotope ratios as an integrated measure of internal conditions influencing carbon assimilation. These methods may help bridge the gap between instantaneous observations of plant responses and information obtained at extended temporal and spatial scales, and help us understand the contribution of different patterns of physiological regulation to processes evident at the whole organism, community, or ecosystem level.