The Effect of Initial Advantage on the Course of Plant Competition

Abstract

It has been suggested that initial advantage is of basic importance in determining the outcome of plant competition. However, evidence points to this being an effect only of competition for light. This theory was tested by growing plants of the grass Festuca ovina, differing only in size, so only their roots could compete. An additive design demonstrated that root competition was occurring, and could be seen in both growth and mortality. In this competition the small plants were at no disadvantage; they grew relatively faster than the large ones, beginning as 10% of the mixture and ending as 30%. Overwhelming importance of initial advantage in size or establishment time is not the basic and universal feature of plant competition that many have thought. It is a feature of competition for light, and does not apply to nutrient competition.