340 PROOEEDINaS OF SECTION D. 



evaporation brought about, robs it of all water-holding capacity. 

 The damp forests of Tasmania, consisting of beech and denso 

 undergrowtii, as also those of Gippsland, northern New South 

 Wales, and Queensland, would be exceptions to this rule. 



It is difficult to obtain data in a recently settled region sucli 

 as Australia. All members of your Committee have been applied 

 to for particulars in the case of any river whose stream-flow has 

 been affected by deforestation at its source, but none are as yet 

 obtainable, with the exception of an interesting report from the 

 Conservator of Forests, South Australia; as also one from the 

 Surveyor-General of New Zealand, who is not a member of the 

 Committee. 



In South Australia, a region much requiring afforestation, and 

 possessing a dry climate, many of the rivers have no perennial 

 stream-flow, and the mountains are either bare or thinly forested, 

 the trees having little influence in protecting the ground from 

 erosion. Mr. Gill, however, instances the Gawler River, rising in 

 hills of soft and easily disintegrating rock, as doing damage by 

 erosion and the silting up of its course. Clearing has been done 

 on the steep sides of the Gawler Ranges, on which erosion must 

 take place, the soil being carried down the river channel. Like- 

 wise, in the mountains south of Adelaide, possessing a wetter 

 climate, wash-outs have taken place on the hill-sides, which are 

 bare and grassed and suffer from over-grazing. In both instances 

 the remedy would be the clothing of the land with forest, much 

 of which is being done in other parts of the State. 



From New Zealand, Mr. Mackenzie, Surveyor- General, writes 

 that the forest at the heads of the main rivers has not yet been 

 interfered with. The damage caused by felling the bush at the 

 sources of small streams flowing into them, particularly on steep 

 and poor soil, is, however, much in evidence. It may be remarked 

 in passing that this denudation on small streams is more particu- 

 larly the evil which your Committee desire to prevent in Australia. 

 The rivers in New Zealand which have caused most damage are 

 those in the Hawkes Bay Province, which rise in the primevally 

 bare mountain zone under heavy rain and suow fall. These have 

 Id flood time a torrential and violent rvm-off, which has created 

 great destruction in the valleys and along their banks owing to 

 the felling of timber there by the early settlers. Had the forest 

 been allowed to stand on the margins of the streams this destruc- 

 tion would have been avoided. Further, through the clearing 

 away of the heavy forest through which the Rangatikei and Maua- 

 watu Rivers and their tributaries originall]^ flowed, immense 

 damage has been caused in alluvial plains, mainly owing to the 

 same mistake, namely, leaving no fringe of timber along the edge 

 of the stream to protect the banks. Mr. Mackenzie computes the 

 damage in these instances at already not less than £50,000. 



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