Walsh. — Effects of Dimppearaiice of the 'New Zeoland Bux/i. 4.37 



The greater part of the forest below a moderate altitude, throughout 

 both Islands, is an open cattle and pig run in which by the browsing, 

 trampling, and rooting of the animals the undergrowth is gradually de- 

 stroyed, the surface-roots lacerated, and the soil trodden into mud, which 

 in sunmier hardens almost into a bed of concrete. The consequence is 

 that the larger trees, deprived of their accustomed nourishment and pro- 

 tection, gradually grow thin and open at the top ; the ground is covered 

 with the fallen leaves, and the debris of centuries, now exposed to the sun 

 and wind, is dried to tinder, when the whole place is ready to be swept 

 by fire, which sooner or later is sure to happen. 



In thickly settled districts, and in those where timber-getting is carried 

 on, the destruction is, of course, most rapid and complete, as every clear- 

 ing, timber-working, and road-line forms a starting-point for the fires, which 

 spread into and kill some portion of the standing bush. And as wherever 

 the fire has once passed it will pass again while there is anything to burn, 

 before very long, in districts where clearings are frequent, the whole bush 

 is consumed, with the exception, perhaps, of that which stands in the 

 lower and damper situations, or which from the conformation of the country 

 is protected from the sweep of the flames. In this way, in a comparatively 

 few years, immense areas have been destroyed in many of the more settled 

 districts, while in others the work is going on more or less rapidly and 

 completely, according to the nature of the bush and the climatic and other 

 conditions. 



Now, it does not require a great deal of intelligence to understand that 

 such a radical alteration in the conditions of the country as is involved 

 in this wholesale destruction must result in very serious consequences, 

 whether for better or for worse. So far, unfortunately, I think it must 

 be admitted, the consequences are very largely for the worse — as I shall 

 endeavour to show. 



The efiects of the disappearance of the New Zealand bush may be 

 roughly classed under tAvo heads — viz., climatic and topographical. 



Climatic, 

 (1.) Rainfall. 

 There is a widespread popular opinion that rain is attracted by standing 

 forest. Much speculation has been expended on this question ; but, so 

 far as I have been able to learn, it has not led to any very satisfactory 

 results. To a superficial viev/, the theory seems to be borne out by the 

 fact that there is generally a greater rainfall in forest-covered districts 

 than there is in open country — as, for instance, the west coast of New Zea- 

 land, which is heavily wooded, is much wetter than the country along the 

 east coast, which is comparatively dry. But this is really to mistake cause 

 for effect ; and the truth is, so far as it can be ascertained, that the amount 

 of precipitation is at least mainly determined by the topographical con- 

 ditions of a country, apart from its vegetable covering — that, in fact, the 

 rainfall is not caused or increased by the presence of the bush, but that 

 the growth and conservation of the bush are promoted by the excessive 

 rainfall. This contrast in the hygrometrical conditions of the east and 

 west coasts is very easily accounted for. The moisture-laden winds from 

 the ocean, meeting the steep face of the chain of hills which — with an 

 occasional break- — extend along the west coast of both Islands, are thrown 

 up into a colder stratum, with the result that the moisture is immediately 



