Bucuanan.—Flora of the Province of Wellington. 211 
where the tertiary limestones prevail, and where there is comparatively little 
bush, sufficient has been done 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 thus 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 paleozoic 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 are 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 soils derived from mesozoic 
rocks, 
The vegetation of the lower altitudes of the Tararuas is chiefly composed of 
that mixed bush so characteristic 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 robusta 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 regards temperature, is mild and equable. 
