KAURI FOREST. 61 
A kauri forest really consists of two distinct associations—the 
kauri association, as briefly described above, and a mixed forest 
association with the taraire or tawa as the leading trees, but with 
other tall or medium-sized trees also—e.g., the tawhero (Weinmannia 
sylvicola), the totara (Podocarpus totara), the miro (P. ferrugineus), 
the rewarewa (Knightia excelsa), the rimu (Dacrydium cupressinum), 
and the tanekaha (Phyllocladus trichomanoides). Kauri forest 
generally speaking, is in a condition of progression or retrogression. 
There may be many large trees and little undergrowth, or a powerful 
undergrowth ready to develop into taraire or tawa forest. These 
two stages are a, distinct expression of the amount of light avail- 
able, the dense undergrowth denoting a maximum, and the close 
forest - roof made by the tall trees, with the consequent scanty 
undergrowth, a minimum. As the illumination increases, forest will 
eventually be replaced by manuka shrubland. Were the climate to 
remain constant, the forest would slowly change and reach its climax 
with tall trees and little undergrowth; then, as tree by tree died, 
light-intensity would increase, seedlings would grow, and rejuvenation 
gradually take place. Should, however, conditions too dry for rain- 
forest arise, then, if they contimued, the forest would give place to 
shrubland. 
The mixed forest (fig. 34) varies in composition according to 
latitude and altitude, but a general groundwork of plants is always 
present. Many species of northern New Zealand are wanting in 
the centre and south of the South Island, and, conversely, the more 
important southern species are less frequent in the north at a similar 
elevation. Latitude 38° forms a fairly definite boundary for quite a 
number of trees and shrubs, and latitude 42° a second boundary, 
though the former, and to a greater extent the latter, is overstepped 
in several instances. 
The pines (species of Podocarpus and Dacrydium), as they are 
popularly called, but more correctly designated taxads, since they are 
related to the yew (Tawus), are everywhere important members of the 
society under discussion. Confined to the far north of New Zealand 
are—the taraire (Beilschnuedia taraire), the mangeao (Litsaea calicaris), 
the makamaka (Ackama rosaefolia), the tawhero (Weinmannia sylvicola), 
the toatoa (Phyllocladus glaucus), the kawaka (Librocedrus Doniana), 
the tree-coprosma (Coprosma arborea), two plants of the true honey- 
suckle family (Alsewosmia), and some other trees and shrubs. 
