320 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1949 
This ‘subtropical’ aspect of the forests can be seen even in northern 
South Island and grades into the characteristic features of the dense 
temperate rain forests of the west coast of South Island. The south- 
ern-beech forests of Nothofagus in the south are clearly Temperate 
Zone forests. (See pl. 1, fig. 2.) 
The mountains in New Zealand cause more changes in the climate 
from place to place than does the latitude. The mountain ranges 
and plateaus of North Island le mostly east of the center. They 
are largely volcanic and influence the vegetation not only through 
their effect on the winds and moisture but also on the soil. The 
volcanic ash and pumice readily absorb more moisture, much of which 
seeps away beyond the reach of the plants growing on the surface. 
Mount Egmont is a majestic isolated volcanic cone on the west coast 
with vegetation in characteristic altitudinal zones from sea level to 
the perpetually snow-covered summit. 
In South Island the rugged Southern Alps parallel the west coast 
and thrust their peaks far into the zone of permanent snow. (See 
pl. 7, fig. 1.) Their highest peak is Mount Cook, its summit 12,349 
feet above the Tasman seashore less than 24 miles to the west. They 
are formed by erosion of uplifted land rather than volcanic activity 
and are composed largely of friable greywacke rock. (See pl. 7, fig. 2.) 
These ranges drain the prevailing westerly winds of most of their 
moisture. Thus the west coast has a heavy rainfall of around 200 
inches a year, while on the plains of the eastern leeward side there 
may be as little as 20 inches. The highest annual rainfall yet re- 
corded is 228 inches at Puysegur Point on the west coast, and the 
lowest, 13 inches, in Central Otago only 150 miles away. Dense rain 
forests cover the steep western slopes and the narrow coastal plain 
below, whereas on the east are the natural grasslands and the broad 
cultivated plains. In Central Otago is a semidesert area. The 
transition fromheavy rain and dense forest to sunshine and almost 
barren eroding slopes may be made in a surprisingly short time in 
driving over the divide. Other ranges and hills, especially the Kaikora 
Ranges in Marlboro and those in the rugged Banks Peninsula, inter- 
rupt this picture and diversify the ecological conditions and vegeta- 
tion. Thus New Zealand has a great variety of distinctive, plant 
formations in a remarkably small space, a fact which makes bota- 
nizing a most interesting and relatively easy occupation. The climate 
of New Zealand has been presented by Kidson (16, 17).! 
THE GRASSLANDS 
The grasslands of New Zealand are the foundation of its agricul- 
tural economy, and one is sure to be impressed by their extent and 
1 Numbers in parentheses refer to the bibliography. 
