Control of Leaf Carbon Assimilation — Input of Chemical Energy into Ecosystems

Abstract

Photosynthesis is the only proeess which provides an ecosystem with chemical energy. It is the important input of assimilates in the form of carbohydrates and other organic compounds which allows plants to grow. This plant organic material is subsequently the basis of life for the secondary and tertiary producers as well as for the decomposers. Therefore, the primary producers, the plants, represent the lowest level in the transfer of carbon and chemical energy in the food chain. Thus, photosynthetic primary production is not only a requirement for the single plant but the essential energy-harvesting proeess for the total biosphere. If we want to understand how ecosystems function, we must analyze the photosynthetic performance of the relevant plants. Such analysis includes determining the quantities of carbon flxed on the one hand, and the physiological and environmental control of the assimilatory proeess on the other. To understand primary photosynthetic production, we must examine the fixed range of internai plant responses as well as the actual plant behavior in response to habitat conditions and climatic influences.