My research is focused on the biological and environmental impacts of the evolution of plant structure, development, and physiology from the Paleozoic colonization of land through the subsequent radiations of land plant form up to and including the Cretaceous radiation of flowering plants. This work involves both living and fossil plants and a wide variety of approaches: developmental and physiological investigation, climate modeling, comparative study of morphological diversity, and cell and tissue-specific analysis of elemental, isotopic, and organic chemistry. These tools have been applied to three connected areas of research that each inform wider questions concerning the evolution of terrestrial environments: the evolution of leaf morphology, development, and physiology with feedbacks to climate and primary productivity, the evolution of cell wall biochemistry and its influence on organic matter burial as a sink in the carbon cycle, and the establishment of early terrestrial life and ecosystems.