Aluminium accumulation in the Australian–New Guinea flora

Abstract

Eighty aluminium-accumulating species were detected among 1324 species tested from the Australian–New Guinea flora. Accumulation was most strongly developed in certain dicotyledons (69 spp.) and Filicales (11 spp.).

A high aluminium content of the organs of accumulating plants appears to be associated with normal metabolism.

Recorded accumulators are mainly restricted to what are usually regarded as the more primitive groups in dicotyledons and Filicales, suggesting that, accumulation is a physiological relic in these groups.

Obligate accumulators are confined to leached acid soils from a variety of parent materials, in comparatively high-rainfall areas.

The re-deposition of aluminium in vegetable debris beneath Australian rain-forest communities dominated by accumulators (e.g. Ceratopetalum apetalum D. Don.) may be an important ecological and pedogenic factor.

The significance of accumulation is discussed along biochemical, ecological, and taxonomic lines.

There is evidence that accumulation is an adjunct of specialization (i.e. relatively narrow physiological tolerances), chiefly among tree species able to exploit impoverished soils in relatively primitive, generally tropical, mesic habitats.

Accumulation seems a useful special character to supplement other data in the clarification of some taxonomic problems.