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.