Effects of a Bush Fire on the Vegetation of Signal Hill. 215 
known as Lion's Head, being situated at the southern end of the hill. 
The rest of the hill consists of a ridge about a mile and a half long and of 
considerably lower altitude than the head, the average height being about 
1100 feet. 
The soil of that part of Signal Hill with which this paper is directly 
concerned is clay, derived from the Malmesbury slates, of which the northern 
end of the hill is composed. The burnt area is by no means uniform in 
character. Several valleys (fig. 2) of more or less equal depth cut 
up the hillside, and these have a vegetation which in its constituents 
shows certain marked differences from that of the ridges in between 
the valleys. 
The bush fire, the effects of which are recorded in this paper, broke out 
on the 5th February 1919, and owing to a strong south-east wind it was 
not extinguished till late on the following day. The approximate extent 
of the burnt area is shown in fig. 1. Owing to the somewhat sheltered 
position of the water-course in each valley, the vegetation there was not 
badly burnt, while elsewhere the fire killed the aerial parts of every plant 
with the exception of a few isolated pines and one eucalyptus tree. These 
i:rees were the only ones on the burnt slope, and they were odd specimens 
which had invaded the area from neighbouring plantations. 
At one spot at the southern end of the area the ground is fenced off, 
and this protected area was valuable in affording a means of judging the 
effects of cattle and man on the regenerative processes after the fire. 
In our * investigations valley A (fig. 2) and its immediate slopes 
provided us with a suitably restricted field for more detailed observations. 
The other parts of the burnt area were visited from time to time, but an 
intensive study was made of valley A alone. 
Detailed observations on the vegetation of this part of Signal Hill were 
not made prior to the bush fire, and consequently it was necessary to rely 
upon the evidence of charred bushes, and the character of a few small 
patches which had escaped the fire, in estimating the original composition of 
the flora. The plant which dominated these slopes as seen from the town 
was Rhus lucida, bushes of which were dotted at frequent intervals over this 
part of the hill. The green colour of these bushes was in marked contrast 
with the prevailing grey-green colour of the smaller shrubs growing in 
between the Rhus bushes. 
The first visit to the burnt area was made eighteen days after the fire, 
and during that interval there had been some rainy days interspersed with 
fine, hot days. 
* During the year 1919 this work was carried out in conjunction with three students — 
Miss S. Garabedian, Miss E. G. Torrance, and Miss W. Wilson. The investigation formed 
part of the work of the M.A. course in botany for that year. 
