Native plant and animal life, like much of the southwest Pacific, is southeastern Asiatic in type and in origin. In the more profuse and varied windward sides there are several general vegetation zones. Along the coasts and in the larger river basins occur alluvial vegetation largely dominated by several kinds of mangrove, which is densest in mud flats washed by the tide. In this zone trees are scattered, and many of them bear useful nuts and fruits. On the slopes and ridges behind the coastal belts are the great tropical rain forests. They make up a dense cover of evergreen trees interwoven with wild creepers and vines. Thick stands of shrubs and smaller trees add to the tropical profusion. Above 2,000 feet the forests thin out and become more heavily coated with moss and lichens, and ferns and orchids attach themselves to the branches. Beyond 3,000 feet is the cloud belt, and above this trees become stunted and are finally replaced by hardy shrubs that cling to the rocks and crags.
On the leeward sides, patches of rain forest are found only in the moister areas. More typical of this zone are thin-leaved trees interspersed in large expanses of meadow and grassland.
A number of native plants are very vital to the Fijian livelihood and some have modern economic importance. Several timber trees are essential to house building, canoe construction, and wood carving. The ubiquitous palms, here as elsewhere in the Pacific, are vital sources of food, drink, building, and weaving materials and cordage. The mangrove provides firewood, house poles, fishing fences, and traps, laths for bows and black dye for their hair and tapa. Valuable starch is secured from the sago palm, which is cut just before flowering, and the leaves are a common thatching material. Various reeds, canes, and bamboos and lianas are useful to Fiji economy. In the drier areas reeds and grasses provide material for house walls, thatch, fish fences, and arrow shafts. Several kinds of trees yield edible nuts and fruits.
Like other central-Pacific island groups, Fiji is poorly provided with indigenous mammals. A small gray rat is a considerable pest in gardens and homes, and a large nocturnal bat, which is called a flying fox, lives in tree colonies and is often seen at dusk in banana groves or other feeding places. All the economically important animals of Fiji have been introduced, such as pigs, fowl, dogs, cattle, horses, sheep, and goats.