Buchanan. — Flora of the Province of Wellington. 211 



■where the tevtiary limestones prevail, and where there is comparatively little 

 bush, sufficient has been clone by a few enterprising settlers to show that this 

 open land is capable of carrying a pasture equal to any in New Zealand, and 

 must, when improved extensively, become a source of great wealth in the 

 future. 



Soils vary according to the character of the rock formations from which, 

 they are derived, and, by thixs supplying in certain cases adaptative food to 

 certain species of plants, influence their geographical distribution ; on some 

 such theory only can we account for the presence of particular species within 

 certain areas, and the apparent inadaptative nature of those areas for other 

 species. So strong is this influence in some cases that soil appears to dominate 

 over temperature. The selected habitats of the Fagus species in "Wellington 

 is a notable instance of this, and so well marked is it in the Upper Wairarapa 

 valley, that if we view the Tararua mountains from a distance of five to seven 

 miles from the east, we may be able to determine the geological formation of 

 the range by its botanical facies. 



The rugged outline of the alpine region is clearly shown against the sky at 

 a varying altitude of 3,000 to 5,000 feet. The vegetation consists of grass with 

 low-growing plants, the result of a low temperature and fierce cold winds. 

 The soil here is derived from palseozoic rocks, but sufficient observations have 

 not been made to show the relation between varieties of soil in this region and 

 the distribution of species, temperature ruling supreme as regards size. 



The middle altitudes of the range show, in the uniform dull-green colour 

 and even surface, the unmistakable presence of Fagus bush, one species 

 creeping up the gullies till it becomes gnarled and stunted in growth. In this 

 middle region the rocks ai'e triassic, and reach to a considerable altitude. The 

 same formation on Wellington harbour hills carries the same species of Fagus 

 from the level of the sea. No doubt the species of this genus have an 

 extensive range, both laterally and altitudinally, for in the South Island they 

 reach altitudes of at least 4,000 feet ; but within this natural range of 

 temperature they show a decided preference for soUs derived from mesozoic 

 rocks. 



The vegetation of the lower altitudes of the Tararuas is chiefly composed of 

 that mixed bush so chai-acteristic of New Zealand scenery, numerous specimens 

 of Fagus being also scattered amongst it. This region is the habitat- of the 

 pines and numerous other genera of varied foliage, the whole, when brightened 

 by the showy flowers of such species as Metrosideros rohusta or Weinmannia 

 racemosa, forming a very pleasing picture. This mixed bush has several 

 lateral extensions on the river flats, and indicates on the hills the area of the 

 tertiary rocks. 



The climate of Wellington, as i-egards temperature, is mild and equable. 



