Forest Types and Life Zones (continued)
FORESTS OF HAWAII NATIONAL PARK
These forests differ so greatly from those of the
continental United States that they require a separate description. This
volcanic park is divided between the islands of Hawaii and Maui. The
Kilauea-Mauna Loa section of the park, in the southeastern portion of
the Island of Hawaii, extends from sea level to an elevation of
13,680 feet at the summit of Mauna Loa and therefore includes the
maximum number of types. On the windward side of the park the trade
winds bring about 100 inches of rain annually, while on the lee side the
annual rainfall is about 15 inches near the coast. This great range in
moisture is reflected in the character of the vegetation, but
temperature is the controlling factor on the higher slopes of Mauna Loa.
The stage of decomposition of the lava flows is also reflected in the
types of vegetation. Lava flows and ash deposits have repeatedly
destroyed areas of vegetation in their paths. Wherever vegetative
development has thus been interrupted the process begins anew.
Strange as it may seem, a large portion of the
coastal-lowland area of the park is in the driest of all the park zones
of vegetation, because it is on the leeward side. Much of the land is
barren lava, but, where vegetation has gained a foothold, it is mostly
of brush and grass species. A small area of rain forest exists on the
rainy portion of the coastal lowland, in which the kukui, or candlenut
tree, and the hala, or screw pine, are typical of the native tree
species. The candlenut tree is so named because its fruit was used by
the Hawaiians as a source of illumination, either by using the kernels
of the kukui nuts or the oil extracted from the nuts.
Above the coastal-lowland forest, at elevations from
2,000 to 4,000 feet in the portion of the park where the rainfall
averages about 100 inches, ohia lehua and tree ferns are type species.
The ohia lehua also extends into the dry formation between those
elevations.
Koa, mamani, and ohia lehua are typical tree species
between 4,000 and 7,000 feet on the southeastern slope of Mauna Loa. The
ohia lehua grows on the more recent lava flows. The seedlings of koa and
mamani are very palatable as forage for cattle and goats, and these
species have been greatly reduced, even eliminated from some areas, by
grazing. Fortunately, all cattle grazing has been eliminated from the
park and the koa is making a vigorous comeback.
Above the 7,000-foot elevation there is a
subalpine shrub formation which extends to about 9,000 feet. There are no
coniferous species within this park.
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