Competition between Eucalyptus melliodora and E. rossii at varying levels of exchangeable calcium

Abstract

E. rossii and E. melliodora were grown in pot culture as competing species at varying levels of exchangeable calcium.

Both height and yield of E. melliodora increased with increasing exchangeable calcium. Regressions of log ratio E. rossii / E. melliodora for both height and yield on exchangeable calcium were highly significant (P < 0.001) and there was no evidence of departure from linearity. The data indicate that plant growth is influenced by the degree of calcium saturation of the soil rather than by the absolute amount of exchangeable calcium. The implications of the results in relation to the natural distribution of the two species are discussed.