THE DISTRIBUTION OF DRY MASS AND PHOSPHORUS IN AN EVERGREEN FYNBOS SHRUB SPECIES, LEUCOSPERMUM PARILE (SALISB. EX J. KNIGHT) SWEET (PROTEACEAE), AT DIFFERENT STAGES OF DEVELOPMENT

Abstract

The distribution of dry mass and phosphorus (P) in the proteoid shrub, Leucospermum parile (Salisb. ex J. Knight) Sweet, was determined at three stages of development following fire, over one year in coastal fynbos vegetation, South Africa. At the seedling stage, a mobilization of P was observed from the hypocotyl and cotyledons to the canopy (40% of total P). The numbers and dry mass of proteoid roots increased between eight and ten months after the fire when there was an apparent decline in total seedling P. The one‐ to two‐year‐old plants showed rapid vegetative growth, the leaves being the major storage organs for P. In the final stage of development (five‐ to six‐year‐old plants), flowering and seed production caused a reduction in P levels in the non‐reproductive parts of the plant and up to 20% of the total P accumulated in the inflorescences. There was a winter peak in root production and P content for one‐ to two‐year‐old plants which had root/shoot ratios of 0.77 and 0.48 respectively; the ratio fell to below 0.2 in the five‐ to six‐year‐old plants. The non‐mycorrhizal root systems of L. parile are dominated by the tap root (up to 88% of total root) but the majority of the roots within the rhizosphere were from neighbouring species. Copyright © 1986, Wiley Blackwell. All rights reserved