A comparison of the sclerophyllous vegetation characteristic of Mediterranean type climates in France, California, and Southern Australia. II. Dry matter, energy, and nutrient accumulation

Abstract

The annual rates of growth (on the basis of dry weight and of solar energy fixed) and nutrient uptakes of garrigue, chaparral, heath, and mallee-broombush growing in the Mediterranean type homoclime of southern France, California, and southern Australia were compared during the first 10 years of succession following fire.

The Australian and Californian communities have an essentially similar growth rate of 640-2000 kg/ha/yr. The growth rate of the chaparral may be slightly greater than that of the Australian cominunities owing to greater availability of the nutrients phosphorus and potassium. The application of phosphorus fertilizer will increase the growth rate of Australian heath to that of the chaparral.

Observations of Long et al. (1967) made on garrigue 10 km north of Montpellier, France indicate a growth rate of c. 1500 kg/ha/yr, essentially similar to that of the Australian and Californian communities. The author's data for a dense, vigorous stand of garrigue growing on relatively fertile calcareous soil 13 km north-west of Montpellier reveal an annual growth rate of 4000-4200 kg/ha/yr.

The growth rates of these distinctive plant communities, composed of entirely different species, are largely controlled by the major factors - solar radiation and available water. In similar homocIimes essentially the same growth rate results. Within limits, soil fertility will play a minor role in controlling the growth rate and consequently the nature of the resultant plant community.