Papua New Guinea together with the West Papua region of Indonesia (New Guinea) make up a major tropical wilderness area that still contains 5% of the original and untouched tropical high-biodiversity terrestrial ecosystems. PNG in itself contains over 5% of the world's biodiversity in less than 1% of the world's total land area. The flora of New Guinea is unique because it has two sources of origin" The Gondwana flora from the south and flora with Asian origin from the west, as a result New Guinea shares major family and genera with Australia and the East Asia, but is rich in local endemic species. The endemicity is a result of mountainous isolation, topographic and soil habitat heterogeneity, high forest disturbance rates and abundant aseasonal rainfall year-round. PNG boasts some 15-21,000 higher plants, 3,000 species of orchids, 800 species of coral, 600 species of fish, 250 species of mammals and 760 species of birds and 8 species of tree-kangaroos out of which 84 genera of animals are endemic. Ecosystems range from lowland forests to montane forests, alpine flora down to coastal areas which contains some of the most extensive pristine mangrove areas in the world. Much of this biodiversity has remained intact for thousands of years because the ruggedness of the terrain made the interior lands inaccessible; furthermore low population density and restrictions on the effectiveness of traditional tools, ensured that these biodiversity was never overexploited.
Even though this biodiversity is on just 1% of the world land mass, it has both global and local value. Most of the ecosystem service provided by the forests and oceans (e.g. water cycling, carbon cycling) is impartial to political boundaries. Within the country, about 79% of the PNG population depend on the biological resource to sustain their physical, spiritual and social livelihoods. The biological resources are a source of food, building material, medicine for minor ailments, logs for canoes. The traditional society revered, and respected nature because it was considered a gift from some ancestor". Currently, the harvesting of natural resource for export is a source of income that sustains the modern PNG economy.