Comparative Photosynthetic Efficiency of Some Native and Introduced Grasses

Abstract

THE ABILITY OF PLANTS to capture light energy is the key to the continual survival of all life. Light absorbed by the green parts of plants is used to fix carbon dioxide from the air and convert it into energy-rich compounds which are then translocated to other parts of the plants. There they may be stored or used to provide energy for growth processes with consequent release of carbon dioxide. This energy from sunlight which is stored in biochemical compounds is the only source of energy for growth and is only a small portion of the total incident sunlight. The rate at which plants can take up carbon dioxide is thus a good measure of the rate at which plants absorb useful energy. However, in practice, only the net exchange of carbon dioxide which results from the uptake by photosynthesis and release by respiration can be measured.