Plant production is the basis for almost all processes in terrestrial ecosystems. Photosynthesis is the only process that introduces energy in a chemical form that can be used to drive biochemical processes, be these within the ecosystem or in organisms living on consumed, harvested or exported products. Other processes within plants convert the primary result of photosynthesis, glucose, into a variety of other compounds, which may be useful or harmful to other organisms. Many aspects of plant production have therefore been studied in great detail. However, we focus on processes and structures at the whole-plant level, although excursions into plant biochemistry are inevitable to establish the basis for functioning at the ecosystem level.

Carbon is the major element, but the limiting constraints from other elements are apparent. Therefore, interactions between carbon, nutrients (or more precisely mineral nutrients), water and light are key topics of this chapter. These interactions also determine the type of plants that will dominate under given conditions and which properties those plants will have.