Spkight. — The l'o»t-(/lari(il Climate of i'antevhury . 415 



south of the river shelter the upper part of the valley from the cold souther- 

 lies, so 4hat the climatic conditions are eminently favourable for the growth 

 of this tree. Its former extension in the vicinity is proved by the logs 

 Avhicli occur now on the south-eastern flanks of Mount Arrowsmith, i)i the 

 valley of the Cameron River (L. Wood and the author), a district which 

 is now marked by the presence of a xerophytic vegetation. 



The extension of this forest into Central Otago was noted by the earhest 

 explorers and settlers, for a noteworthy feature of the land-surface in its 

 original condition was the occurrence of enormous numbers of logs of totara 

 lying on the hillsides and flat-topped mountains, as well as buried in the 

 slips and bogs of that now treeless and steppe-like region. 



In his sketch of the " Botany of Otago " (Trans. N.Z. Institute, vol. 1, 

 1869) Buchanan says, " The general facies of the vegetation of the province 

 on its eastern watershed is grassy, the greater part being open grass land 

 with comparatively small areas of bush along the coast-line and in the gullies 

 of the mountain-ranges, whereas on the western watershed the whole country 

 from the sea to the altitude of 3,000 ft. on the mountains is covered with 

 bush. It is evident that at no distant time the greater part of the province 

 was covered with forest. On mawy of the grassy ridges may still be seen 

 the remains of large trees, and over large areas the surface is dotted with 

 little hillocks and corresponding hollows produced from the upturned roots 

 of trees which have been blown over, generally in the line of the j)revailing 

 winds, after their destruction by fire, and no doubt there have been many 

 denudations and reproductions of bush. At the beginning of the settle- 

 ment large tracts of the province were being reclothed with bush, but as the 

 country was opened for cattle and sheep runs this new growth was again 

 burnt off, and a hixuriant growth of native grasses appeared without seeds 

 being sown." This account was written in the year 1865, and is specially 

 important as showing that a competent observer at that early date was of 

 the opinion that a succession of forests had covered the treeless hills of 

 Otago. 



The existence of vast numbers of totara logs in Central Otago is testi- 

 fied to by many other observers, all of whom have acknowledged that the 

 prostrate trees indicate the presence of a forest of wide extent. The latest 

 reference to this appears to be that by Professor Park, in Bulletin No. 5 (n.s.). 

 New Zealand Geological Survey. The author there says, " Forest vegeta- 

 tion is entirely absent, but there is evidence that it was not always so. 

 Above the 2,0()0 ft. contour-line of Mount Malcolm and Mount Hocken there 

 are still many logs of totara [Podocavpus totara), charred and well preserved, 

 lying on the surface of the ground. The older settlers state that totara logs 

 were at one time common on the Dunstan, Pisa, Carrick, and Eemarkable 

 Mountains, and proved of great value to the early pioneers for fuel and 

 fencing purposes. The totara forests apparently flourished above the 

 flood-level of the Pleistocene rivers that filled the old lake-basins. They 

 were probably destroyed by fire." 



The occurrence of the totara in the peat-bogs of Otago is referred to 

 earlier in this paper. 



Although the evidence for the wide extent of this forest is conclusive, 

 it cannot be maintained that it covered the face of the country as completely 

 as do the forests on the western slopes of the Alps. All the same, it may 

 have done so. The usual sequence of events in the changes which forest 

 experiences in this region is that when destroyed by fire, wind, or any natural 

 •cause it turns into tussock steppe. The transition is at times very rapid. 



