Conifers, pines (Pinus oocarpa and others), mostly limited to the mountain ridges and disturbed areas, and podocarps
(Podocarpus guatemalensis) are scattered throughout the forest.
He never once considered that there may have been a balance factor that had ensured the forest dominance of the conifers such as the podocarps
, and that kauri had previously been maintained by the browse of an avifauna which filled the functions of elephants, giraffe, deer and antelopes in other lands.
Imported pine trees--originally grown for timber--create valuable forest canopy and nesting sites until native podocarps
can grow tall enough to take over that role.
For example, podocarps
near main highways can be showered by carbon particles from diesel trucks, but one never sees such particles in the pollen chamber.
and kamahi (Weinmannia racemosa), with scattered podocarps
(especially matai, Prumnopitys taxifolia, and rimu, Dacrydium cupressinum).
Pollen in the lower zone is dominated by forest trees, notably Ascarina, Dacrydium and other podocarps
, and Metrosideros, with the latter increasing up the profile (Fig.
The Southern Hemisphere also contains many forests dominated by conifers such as podocarps
(Podocar-pus), dammar or kauri pines (Agathis), monkey puzzles (Araucaria), Rimu pines (Dacrydium), etc.
Cameron (1960) recorded a 36% increase in the height growth of seedlings of podocarps
(mainly Dacrydium cupressinum and Podocarpus totara) following trenching of plots containing 15-30 yr-old seedlings in the North Island of New Zealand.
ferruginea (Table 3), implying that the advantage of the podocarps
in the shade may be offset by much faster growth of new N.
At least two different podocarps
are represented by leaf macrofossils.
40m for a site where a tephra layer is thought to have been bioturbated largely by root growth from successions of Nothofagus and podocarps
in New Zealand.
This is shown by the relict species of podocarps
(Podocarpaceae), the conifers in the temperate forests of the Southern Hemisphere, and the swamp cypress or bald cypress (Taxodium distichum) in the southeastern United States.