ECOLOGY OF RAINFOREST AND SCLEROPHYLLOUS COMMUNITIES 
IN THE MITCHELL RIVER NATIONAL PARK, GIPPSLAND, VICTORIA 
D. R. Melick 
School of Botany, University of Melbourne, Parkville, Victoria 3052 
Melick, D. R. , 1990:11:30. Ecology of rainforest and sclerophyllous communities in the 
Mitchell River National Park, Gippsland. Victoria. Proceedings of the Royal Society of 
Victoria 102(2): 71-87. ISSN 0035-9211. 
A survey of the tloristics and soils was conducted in a 143 hectare area within the 
Mitchell River National Park, Victoria, where rainforest patches occur amid sclerophyllous 
communities. These rainforest patches are amongst the most south-westerly expression of 
“tropical” elements in Australia. Computer sorting of the survey data delineated six major 
community types, ranging from undisturbed and disturbed rainforest to wet and dry 
sclerophyll communities. The topography of the site and disturbance regimes were the major 
factors delimiting these community types. Undisturbed rainforest patches were restricted to 
fire protected niches while the floristic composition and structure of sclerophyllous 
communities appeared to be determined by a combination of site insolation (moisture), fire 
susceptibility and previous land clearing activities. Although soil chemical properties varied 
across the site, edaphic factors were regarded as being of secondary importance to 
topography and disturbance in delimiting the plant communities. 
THE FLORA of Gippsland has long been recog¬ 
nized as an unusual melange of community 
types, varying from dry sclerophyll woodland 
through to outliers of warm temperate rain¬ 
forest. This mixture of vegetation types is 
thought to result from the mild climate, erratic 
rainfall and history of disturbance in this region 
(Patton 1930, Land Conservation Council 
1985). In one of the earliest floristic descript ions 
of East Gippsland, Patton (1930) was intrigued 
by the occurrence of “tropical” and warm tem¬ 
perate species of trees, lianes and even an iso¬ 
lated community of the palm Livistona australis , 
together with eucalypts such as Eucalyptus polv- 
anthemos at the eastern limit of their distribu¬ 
tion. The coexistence of these species led him to 
describe East Gippsland as “a meeting ground of 
two floras; tropical rain flora with a dry sclero- 
phyll flora.” 
At their southwestern-most limit in East 
Gippsland, warm temperate rainforests are 
found only in isolated pockets on a sheltered 
arm of Lake King, along the Mitchell River gorge 
and in one of the headwaters of the Freestone 
Creek at Mt Moornapa (Ashton & Frankenberg 
1976, Cameron 1984). The flora of these western 
pockets is somewhat depleted in comparison 
with the rainforests further east (Cameron 1984, 
Melick 1988), but they represent the most sou¬ 
therly extension of the east Australian warm 
temperate rainforest elements, with the excep¬ 
tion of Acmenasmithii which is present amongst 
cool temperate elements at Wilsons Promontory 
(Ashton & Frankenberg 1976). Moreover, the 
occurrence of Brachychiton populneus on the 
drier slopes at the Mitchell River is disjunct 
from its usual distribution in inland New South 
Wales and southern Queensland (Beadle 
1981). 
Many of the Gippsland rainforest communi¬ 
ties have been subjected to fire, allowing the 
penetration of sclerophyll species, sometimes as 
emergents. Fossil evidence suggests that these 
small patches of rainforest represent the last ves¬ 
tiges of what were much more extensive warm 
temperate rainforests throughout eastern Vic¬ 
toria in the mid-Tertiary (Duigan 1951, 1965). 
The extent of the warm temperate rainforests is 
thought to have been reduced by fluctuations in 
climate together with increased fire frequencies 
(Ashton Sc Frankenberg 1976, Walker & Singh 
1981). Contemporary rainforest distribution in 
Gippsland is likely to be regulated by moisture 
availability, disturbance and soil factors (Land 
Conservation Council 1985). 
Although broad scale floristic surveys of the 
Gippsland region have been carried out pre¬ 
viously (Gullan et al. 1981, Forbes et al. 1982), 
the present paper examines in detail the hetero¬ 
geneous vegetation within a section of the Mit¬ 
chell River National Park to determine the rela¬ 
tive importance of topography, climate, distur- 
71 
