Vegetation pattern and environmental correlates in coastal forests of the Australian monsoon tropics

Abstract

A transect study o f coastal forest vegetation on a lateritic peninsula in the N o r t h e r n Territory revealed four distinct communities; eucalypt forest, mixed eucalypt f o r e s t -m o n s o o n thicket, pure m o n s o o n thicket and fringing coastal mangrove forest. The mangrove forest occurred in saline mud, the mixed and pure thicket on red earths and the eucalypt forest on both red and yellow earths. The eucalypt forest had less moisture in the surface soil t h a n the other communities on the gentle slope above the mangroves. Evidence of past fire occurs in all the terrestrial communities, but the pure thicket is associated with a t o p o g r a p h i c position better protected f r o m fire down-slope from the mixed community. Eucalypt regeneration in the mixed forest may be m a i n t a i n e d by fires that have penetrated it from the frequently burnt eucalypt forest. It is possible that the mixed c o m m u n i t y is a fire sere occupying a site otherwise capable of supporting a pure thicket. However the pattern of vegetation has changed little in the recent past.

Response of a monsoon forest‐savanna boundary to fire protection, Weipa, northern Australia

“…Dry season surfaee soil moisture eontent was not significantly different between the monsoon forest and savanna. This is in contrast to the findings of Bowman and Dunlop (1986) for a coastal monsoon forest-savanna boundary in the Northern Territory (NT). Russell-Smith (1986) measured xylem pressure potentials of some monsoon forest tree species which occur across savanna-forest boundaries in the NT.…”

“…Bowman (1991) showed that, if late dry season fires transgress the boundary, most monsoon forest tree species have well developed vegetative recovery mechanisms. These facts account for the temporal stability of most monsoon forest boundaries (Bowman & Dunlop 1986). Differenees in fire regime may also account for the significantly higher concentrations of nutrients in monsoon forest soil than in savanna soils (Kellman 1984;Bowman & Mmchin 1987).…”

“…The only physical difference between the savanna and the monsoon forest soils detected in this study was the greater amount of bauxitie pisoliths in the surface soil of the monsoon forest. Bowman and Dunlop (1986) showed that surface soil concentrations of ferruginous pisoliths were significantly higher in a similar type of monsoon forest community than in the surrounding savanna in the coastal regions of the NT. It is unclear what effect these gravels have on moisture conditions or tree growth (Fensham 1990).…”

Seasonal habitat use by flying‐foxes, Pteropus alecto and P. scapulatus (Megachiroptera), in monsoonal Australia

“…Haynes, 1985;Bowman et al, 1988;Press et al, 1995), and are also started by lightning strikes. Fires have a strong in¯uence on vegetation composition and plant phenology (Bowman & Dunlop, 1986;Setter®eld & Williams, 1996).…”

A transect study of the Eucalyptus forests and woodlands of a dissected sandstone and laterite plateau near Darwin, Northern Territory

“…mangrove (e,g, Thom et al 1975;Wells 1981;Semeniuk 1985) and wetland (e.g. Williams 1979Williams , 1984, and with several detailed vegetation descriptions recently becoming available for particular areas (e,g, Specht et al 1917: Langkamp et al 1981Burgman & Thompson 1982;Beard et al 1984;Bowman & Wightman 1985;Rice & Westoby 1985;Taylor & Dunlop 1985;Bowman 1986;Bowman & Dunlop 1986). Much of the area of the wet/dry tropics consists of extensive plateaux whence arise the streams that flow into plain and wetland, and the dissected edges of which contain monsoon forests (Taylor & Dunlop 1985).…”