Plant self-thinning dynamics.

Plant self-thinning of Hellianthus annuus is examined and it is shown that the mean leaf area ratio is equal to the mean plant density ratio to the power-4/3 independent of the mean plant dry weight and independent of the light intensity over the experimental range considered. The constant term of this basic self-thinning equation is identified, in terms of the mean leaf area and mean plant density values (L c and p c respectively) for the plant population in its earliest competing post germination stage and in terms of the derivatives (d log L/d log p)1=(d log L/dt)1/(d log p/dt)1=-4/3 which is independent of light intensity, as L c pc (-4/3).