Species richness of rainforest stands on non-serpentinite and serpentinite substrates in the Rockhampton – Marlborough area of central Queensland

More than 60% of the 285 species collected in the rainforest stands in the Rockhampton-Marlborough area of Central Queensland were distributed at random by birds, bats and possums, mostly by endozoochory. A further 14% have appendages that aid wind dispersal, while 11% need strong winds to disperse seed whenever they drop to the ground. The distances between the rainforest stands suggest that the random distribution of species is not a recent phenomenon. It is probable that rainforest became widespread in Central Queensland during a perhumid period over 100 000 years ago. The species richness in each rainforest stand depends on the area of each well-watered habitat. Aerodynamic forces (frictional, thermal, and evaporative) affect the edges, more than the centres, of isolated stands of rainforest; annual growth of any stand thus decreases as its area becomes smaller. The number of species collected in each non-serpentinite rainforest follows a typical species-area curve with optimal species richness being found in the Fitzroy Caves rainforest with an area over 100 hectares. As with the eucalypt vegetation on the serpentinite outcrop in Central Queensland, the growth of the serpentinite rainforests is affected by the dearth of phosphate and ammonium ions in the soil, together with the toxic effects of nickel. Less than half of the rainforest species that are found in non-serpentinite rainforest pockets of the same area are recorded in the serpentinite stands