Biogeographical zones of Kona
Biogeographical zones are areas that support different life forms because of differences in weather, soils, and temperatures. Above all, rainfall determines the biogeographical zones of Kona. There is little rainfall along the coast, but as elevation increases, rainfall increases. The added moisture allows forests to grow, which in turn enables the development of soils. Above 6000 feet it is again very dry and vegetation and soils are sparse.
Along the Kona coast there was once a patchwork carpet of flowering ground covers. Behind that, a forest of fan palms stretched across the dry lowlands; in places the palms gave way to thickets of trees and shrubs now extinct or dangerously rare. There were groves of sandalwood, and the rainy middle elevations were dominated by ‘ōhi‘a and towering koa trees. Above the rainbelt, the forest thinned and a scrub forest of yellow flowered māmane and naio stretched up to the timberline of the volcanoes.
Seabirds settled in great flocks along the shoreline, and wheeled over the schooling fish off shore. Big flightless ducks and geese scoured the forest understory, grazing and browsing, while honeycreepers of many colors flitted through the trees, each a specialist at harvesting something from the forest, from insects, to nectar, to hard-shelled seeds and succulent fruits. Clouds of native moths and butterflies filled the air among the trees and shrubs, while beetles stalked the stems below for prey.
Hawaiians recognized the subtle interdependence of living things, soils, and weather, and took that into account as they lived and farmed and gathered from the forests of Kona. Most of their settlements were along the coast, probably because in Kona fresh water is scarce in the upland areas as there are no streams. They gathered hardwoods and grass from the dry forest and grasslands behind the coast. They farmed the Kona lands from an elevation of about 500 feet to about 2500 feet, where increasing rainfall provided for the soils and water they needed to grow their crops. In the wet upland forests above their farms, they harvested mighty koa for canoes and trapped birds for feathers to decorate the capes and helmets of the chiefs.