103 



THE INFLUENCE OF BUSH FIRES ON THE 

 DISTRIBUTION OF SPECIES. 



By Rev. R. Collie, F.L S. 



[Read before the Royal Society of N.8.W., August 3, 1887.'] 



Some time ago it was my privilege to spend three weeks in a part 

 of the country very seldom visited, either by the public, or scientific 

 traveller, and presenting nearly the same appearance as it did to 

 Robert Brown when he was collecting his specimens in the 

 beginning of the century. The scrub which covered a great part 

 of the country was very dense, composed chiefly of ti-trees, 

 banksias, and a few dwarf gums. The soil was a loose sandy one, 

 with a few rocks cropping through in different parts to the surface; 

 but in another part it was boggy, and in winter formed a swamp. 

 A small creek ran through the scrub, the banks of which were 

 covered with ferns, and various kinds of mosses. Not far from the 

 creek a few years ago a bush fire broke out, and assumed rather 

 alarming dimensions, forcing its way through the scrub for the 

 distance of nearly a mile, until its progress was stopped by a swamp. 

 The widest part swept by the fire was nearly half a mile in width, 

 but it narrowed towards the -swamp to the width of a few yards. 

 It was interesting to observe the contrast of the " flora " of the 

 original scrub, and that of the ground cleared by the fire. 



It so happened I was visiting in the district in the month of 

 October, when the wild flowers are at their best, and I was very 

 much interested in going over the ground again and again, and 

 collecting the various species found there. I found that those bushes 

 which formed the original scrub, (ti-tree, banksias, and dwarf 

 gum), did not re-appear in the cleared ground as might have been 

 expected. Banksia ericifolia, which was abundant in the original 

 scrub gave place to Banksia aeinula. Neither of the two ti-trees 

 ( Leptospermun attenuatum and L. jjauciflorwrn) re-appeared, nor 

 did any other species take their place. The same may be said 

 with reference to the dwarf gum, ( Eucalyjitus obtusiflora). The 

 cleared ground was well covered with a large number of species of 

 wild flowers, not one of which was found in the original scrub ; 

 the seeds of which must have been carried a considerable distance 

 by the wind, and scattered broad-cast over the ground fitted to 

 receive them. Foremost (in appearance at least), were two species 

 of grass-trees, ( ' Xanthorrhcea hastilis and X. minor), a genus of 

 plants peculiar to Australia, according to Bentham and Mueller. 



