My research focuses on three related themes in plant physiological ecology: 1. The physiology of plant performance under field conditions – my research addresses the internal and external constraints on plant resource acquisition (e.g. carbon and nitrogen) in response to variation in environment. This is a fundamental theme in plant biology, with links to a range of important applications in plant production and environmental science. 2. The physiology of forest carbon exchange – the application of the first theme has had its most obvious manifestation in forest carbon exchange. This is essential research because carbon exchange in the world’s terrestrial ecosystems has such a strong influence on the global atmosphere. This research has focussed on factors regulating photosynthesis and respiration in leaves and the scaling of these processes to the canopy level. This is a theme with significant current interest given the importance of forest productivity to human goods and services. 3. Global change biology – my research in the two preceding areas has directly informed my current research which attempts to address the responses of photosynthesis and respiration to changing temperatures on calculations of forest carbon budgets. This theme has developed a global resonance in recent years which I would not have predicted when I first developed the interest!