68 
E. A. CHESTERFIELD ET AL. 
predominantly in the Central Highlands. The 
southern New South Wales form is less glaucous, 
less vigorous and has marginal glands on its 
mature leaves. The major occurrence of this 
form is on Errinundra Plateau. It also occurs 
intermixed with the West Gippsland form on the 
western slopes of the Baw Baw Ranges and on 
the Toorongo Plateau; however, the West 
Gippsland form does not occur naturally in East 
Gippsland. 
In the Victorian Central Highlands, E. nitens 
is often found in association with or in close 
proximity to the cool temperate rainforest spe¬ 
cies Nothofagus cunninghamii (Hook.) Oerst. 
and Atherosperma moschatum Labill. Mixed 
forest associations with Elaeocarpus holopetalus 
F. Muell and A. moschatum replace N. cunning¬ 
hamii in East Gippsland beyond the natural 
range of that species. In areas where the under¬ 
storey consists of a dense growth of A. moscha¬ 
tum, E. holopetalus and associated cool tem¬ 
perate closed forest species, an almost complete 
dominance of the site by E. nitens is often ap¬ 
parent. In northern New South Wales, mixed 
forest reoccurs with associations between E. nit¬ 
ens and Nothofagus moorei (F. Muell) Krasser 
(Pederick 1977). 
The development of cool temperate closed 
forest understories has been associated with 
crown die-back in mature E. delegatensis forest 
in Tasmania (Ellis 1964, 1971, Ellis et al. 1980) 
although associated E. dalrympleana Maiden 
was unaffected. Ellis et al. (1980) concluded that 
depressed root temperatures due to the en¬ 
croachment of closed forest may be important in 
the “decline'’ of E. delegatensis , as the deterio¬ 
ration could be reversed by cutting or burning 
the understories. A mean annual soil tempera¬ 
ture below 7°C was identified as the critical point 
at which the growth of E. delegatensis deterio¬ 
rated (Ellis 1971). Although healthy and un¬ 
healthy stands differed little in winter soil tem¬ 
peratures, unhealthy stands had summer tem¬ 
peratures below 10°C. This suggested that soil 
temperature could be an important factor in- 
fuencing the natural distribution of eucalypts 
(Ellis 1971). 
The strong topographic and floristic similari¬ 
ties between the declining E, delegatensis forests 
of Tasmania and the apparently unaffected E. 
nitens forests of Errinundra Plateau suggested 
that E. nitens might be more tolerant of low soil 
temperatures than E . delegatensis. This factor 
might also influence the distribution of E. reg- 
nans and E. fastigata in eucalypt-rainforest as¬ 
sociations in Victoria. The aim of this study was 
to test this experimentally under controlled con¬ 
ditions. 
METHOD 
To investigate the effect of lowered root tem¬ 
peratures on eucalypts occurring in the montane 
zone and likely to form an association with a 
rainforest understorey, seedlings of four com¬ 
mon montane eucalypts were grown at tempera¬ 
tures near that identified by Ellis (1971) as 
critical to the onset of die-back. Seedlings for the 
trial were grown from provenances listed in 
Table 1. Seeds of E. nitens were collected from 
several trees at each provenance and care was 
taken to distinguish between the southern New 
South Wales and West Gippsland forms at Mt 
Toorongo. Seeds of E. delegatensis, E. fastigata 
and E. regnans came from bulked seed lots and 
Species 
Locality 
Latitude 
Longitude 
Elevation 
(m.a.s.l) 
Form 
E. nitens 
Royston River, 
Central Highlands 
37° 25' 
146° 53' 
1000 
West Gippsland (CR) 
E. nitens 
Mt Toorongo, 
Central Highlands 
37° 50' 
146° 07' 
1200 
West Gippsland (CT) 
E. nitens 
Mt Toorongo, 
Central Highlands 
37° 49' 
146° 07' 
1000 
Southern NSW (ET) 
E. nitens 
W Errinundra, 
East Gippsland 
37° 19' 
148° 52' 
1000 
Southern NSW (EE) 
E. delegatensis 
Delegate River, 
East Gippsland 
37° 17' 
148° 50' 
1000 
East Gippsland 
E. fastigata 
Delegate River, 
East Gippsland 
37° 17' 
148° 50' 
1000 
East Gippsland 
E. regnans 
Nunnet, East 
Gippsland 
37° 14' 
148° 05' 
1000 
East Gippsland 
Table 1. Eucalypt species and provenance. 
