South African Journal of Science
On-line version ISSN 1996-7489
MIDGLEY, J.J and REBELO, A.G.. Life-history evolution as an explanation for the absence of the tree life-form in Cape fynbos. S. Afr. j. sci. [online]. 2008, vol.104, n.3-4, pp. 89-90. ISSN 1996-7489.
Invasive exotic tress are able to grow tall (more than 15 m) in the fynbos environment of the southwestern Cape of South Africa, whereas the tallest fynbos plants, generally from the Proteaceae, have much shorter maximum stature (less than 5 m). Analysis of the Protea Atlas Database for the Cape shows a positive correlation between age at maturity and maximum plant size. Monographs of the Proteaceae indicate a shorter period to maturity for reseeders than resprouters. We propose an evolutionary hypothesis for the absence of trees in the fynbos; predictable, frequent fires have favoured early maturity and this has discriminated against any strategies with delays to maturity (such as experienced by resprouters and trees).