Simulation of Shoot/Root Ratio Changes During Vegetative Phase and as Affected by Environmental Factors

By simulating some physiological processes-photosynthesis, respiration, translocation,growth and others-together with their interactions, a model has been constructed which can predict the change in shoot/root ratio during the vegetative phase under the influence of several environmental factors. The results of the running of the model show that it can predict well the allometric growth of shoot and root, the decrease of shoot/root ratio with increasing irradiance and decreasing soil water potential, and the change of shoot/ root ratio with temperature. They also illustrate how the shoot/root ratio gradually returns to its normal value after it is changed drastically by partial defoliation and root pruning. The simulated results fit the observed phenomena quite well, though there are some assumptions taken which may need to be refined.