418 Tra nsa ction s . 



tentative, and is based on observations of the ecological habits of the totara 

 which are decidedly incomplete. 



Reasons for the Disappearance of the Forests. 



Although the main point to consider in this paper is the question of the 

 establishment of the forests on an ice-swept country, yet their disappearance 

 has also an important bearing on the question. In several parts of the 

 country it has been noticed that the bush is shrinkiiig even when protected 

 from the interference of man and animals. Far larger areas in the North 

 Island were once covered with kauri forest than those which existed in the 

 memory of man, as is proved by the extensive deposits of subfossil kauri- 

 gum far away from growing timber. This is quite apart from the gradual 

 restriction of the kauri forest which has gone on in Tertiary times from 

 its former wide range, proved by the occurrence of fossil kauri-leaves in 

 various Tertiary deposits in Otago. The destruction of the forests con- 

 taining totara, which once existed in Canterbury and Otago, has usually 

 been put down to the fires lit either accidentally or intentionally by the 

 Maoris, a conclusion largely based on the fact that many charred logs were 

 found by the earliest settlers. There is a Maori tradition, mentioned pre- 

 viously, of the destruction of these forests by extensive fires at one period 

 of Maori history ; but the evidence from Maori tradition is almost valueless, 

 and there are indications from Canterbury which certainly point in a con- 

 trary direction. Banks Peninsula was thickly peopled by Natives at the 

 time of the arrival of the first settlers and it showed no signs of the ravages 

 by fire (S. C. Farr). If fires had been lighted by the Maoris this is just the 

 place where they should have occurred, yet the hillsides, with the exception 

 of the highest points and some of the headlands, were completely clothed 

 with bush right up to the very settlements of the Natives. The bareness of 

 the headlands seems to have been due to other causes, since from their re- 

 lative inaccessibility they were not Ukely to have been swept by fire. These 

 open spaces were probably due to that natural succession of events which 

 turns forest into grass land, but the factor controlling this change does not 

 seem to be well understood, and it may be a function of the change 

 in climate. At the same time, it must be admitted that continuous and 

 repeated fires in dry seasons, fed with accumulations of dry tussock- grass, 

 would restrict materially the areas covered with bush, and without doubt 

 these fires occurred. 



It seems impossible, however, that fire could have destroyed a forest 

 of wide extent and left no patches in sheltered gullies and other places which 

 would have formed centres for its renewal had climatic and other conditions 

 been favourable. If the climate is favourable for the renewal of the rain 

 forest it is difficult to destroy it by burning, even when this is carried on 

 for the express purpose of clearing the land for pastoral purposes. In the 

 case under consideration, the charring of the logs mentioned previously 

 has been caused largely by tussock-fires since the arrival of the white man, 

 although the Maoris certainly carried on a sporadic burning in pre-Europeau 

 times. It is a remarkable fact, however, that the existing patches of bush 

 occur i I just those situations in which they might be expected to occur 

 from ecological considerations had a slight desiccation of the climate come 

 about. The bush has disappeared from situations where from exposure 

 to wind, lack of moisture, &c., they would naturally feel first the effects 

 of slightly drier atmosphere. The change required to produce this disap- 

 pearance is no doubt very slight, as httle is required to upset the delicate 



