CONDITIONS FOR LIFE OF HIGH-MOUNTAIN PLANTS. 99 
the alpine belt. At a lower altitude another line occurs, marking 
the point at which snow may lie for a week or two. This forms the 
boundary between the wpper and lower subalpine belts, into which 
the subalpine belt may be conveniently divided, and it occurs at 
about 1,000 feet below the boundary of the alpine belt. At another 
1,000 feet below this comes the lower boundary of the lower subalpine 
belt, it marking the line where snow generally lies for only a few 
days at a time. ‘Two thousand feet below this again marks the 
lower limit of the montane belt, where snow falls more or less every 
year, but where it usually melts soon after it falls. This belt extends 
downwards from the subalpine belt to 1,000 feet altitude, when the 
upper limit of the lowland belt is reached. 
If the whole high-mountain flora be considered, the lower subalpine 
belt contains approximately 700 species, the upper subalpine 750, 
and the alpine 400; but only about 100 of the latter reach the 
highest summits suitable for plant-life. 
The plant inhabitants of the high mountains have to endure 
much harder times than their relatives of the lowlands. Frost 
occurs at all seasons of the year, and in winter may last for many 
days; the wind is frequently extremely violent; rain and mist 
abound, especially on the western mountains of the South Island 
and on Mount Egmont; the soil is frequently extremely cold, at 
which time the activity of the roots in bringing water to the leaves 
is greatly reduced; a dry and a moist atmosphere may follow one 
another closely ; short periods of drought must be met equally with 
long periods; snow may fall during any month of the year, and 
from winter onwards it may lie for months, especially in gullies ; 
in the middle of summer the soil-water may be extremely cold, even 
on the hottest days; many plants have a brief growing-period but 
a long daily illumination; the intensity of the sunlight increases 
with altitude; the soil may be very hot and the air comparatively 
cold; disintegration of the surface soil is always in progress ; snow 
avalanches are not infrequent. 
That the plants of the high mountains must live strenuous lives 
the foregoing paragraph clearly foreshadows. But they are well 
equipped by nature, and their growth-forms and organs are attuned 
to the alpine life. Evidently they must be prepared for lack of 
water at times; they must be able to resist the tempest; the 
tremendous pressure of the snow must have no permanent effect on 
