Soils of the Pacific

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Soils of the Pacific

What is Soil?

Soil is the biologically active, porous material that has developed in the uppermost layer of the Earth's crust. It is made up of a mixture of broken rocks and minerals, living organisms, and decaying organisms called humus. Humus is dark, soft and rich in nutrients. It is one of the principal substrata of life on Earth, serving as a reservoir of water and as a medium for the filtration and breakdown of injurious wastes, and as a participant in the cycling of carbon and other elements through the global ecosystem. Soil has evolved through weathering processes driven by biological, climatic, geologic, and topographic influences.

Factors affecting Soil Formation in the Pacific

Soils are natural expression of the environment in which they were formed. They are derived from an infinite variety of materials that have been subjected to a wide spectrum of climatic conditions. Soil development is influenced by topography on which soils occur, the plant and animal life which they support and the amount of time which they have been exposed to these conditions. Scientist recognizes five major factors that influence soil formation; Parent material, Climate, Living organisms (native vegetation), Topography, and Time.

The combined influence of these soil-forming factors determines the properties of a soil and the degree of expression.

Parent Materials- refers to organic (such as fresh peat) and mineral material in which soil formation begins. Mineral materials include partially weathered rock, ash from volcanoes, sediments moved and deposited by wind and water, or ground up rock deposits by glaciers. the common parent materials found in the Pacific are volcanic basalts (Samoa), or andesites (Chioseul, Solomon Islands), volcanic ash and scoria (a porous volcanic rock, heavier then pumice) ( Taveuni, Fiji); weathered uplifted mantle material (New Caledonia); carbonates ( Funafuti, Tuvalu),...