Aspects of the development of mangals in the Townsville Region, North Queensland, Australia

Abstract

The development of mangals and the underlying factors which control the zonation of mangroves have been considered for some time. As a rule these two aspects of mangrove swamps have been considered in isolation from each other. The idea has been suggested that contemporary factors such as salinity, frequency of inundation and duration of tidal emergence and height of the land surface are the most important controlling influences of the zonation of mangroves (Watson 1928; Davids 1940; Macnae 1966, 1967, 1968; Baltzer 1969; Clarke and Hannon 1969). The relationship between geomorphological and soil textural factors has also been noted (Gledhill 1963; Giglioli and Thornton 1965; Thom 1967; Hervieu 1968; Vieillefon 1969). More recently a temporal element has been introduced into such a discussion (Thom 1975; Thom et al. 1975). The relationship of the soil chemical status of the underlying substratum to the zonation of mangroves has also been commented upon (Navalkar and Bharucha 1950; Thornton and Giglioli 1965; Giglioli and King 1966; Vieillefon 1969; Bunning, cited in Ding Hou 1958; Kartawinata and Walujo 1977). However, the latter group of studies has tended to consider one type of coastline only and it is unclear as to how widespread the relationship is. The object of this paper is to consider the vegetation/soil relationships on both an open accreting coastline and an estuarine coastline (Diemont and Wijngaarden 1975) in the Townsville region, north Queensland.