The Solomon Islands rain forests are a terrestrial ecoregion covering the Solomon Islands (archipelago).
Geography
The ecoregion covers the Solomon Islands archipelago, which is divided between the countries of Solomon Islands and Papua New Guinea. The archipelago's northern islands, Bougainville and Buka, are part of Papua New Guinea. The rest of the archipelago is within the nation of Solomon Islands. The ecoregion excludes the eastern islands of the nation of Solomon Islands, the Santa Cruz Islands, which lie in the Vanuatu rain forests ecoregion together with the neighbouring archipelago of Vanuatu. The archipelago extends approximately 1450 km from northwest to southeast, between 5° and 12° South latitude.
Bougainville is the largest island, about 200 km long and from 50 to 60 km wide with an area of almost 9000 km<sup>2</sup>. The island has a central mountain range, the northern part of which is known as the Emperor Range, and the southern part, separated by a lower saddle, as the Crown Prince Range. Mount Balbi in the Emperor Range, at 2,715 metres elevation, is the highest peak in the archipelago. Volcanic rocks are common, with dating back approximately 30 million years. The Panguna mine in the Crown Prince Range, currently closed, is one of the largest copper mines on earth. The Keriaka Plateau in northwest Bougainville, south of Mount Balbi, is a karst plateau formed of weathered foraminiferous limestone dating to the lower Miocene.
Lowland forests are made up of trees up to 35 meters high forming a closed canopy, with Vitex cofassus and Pometia pinnata as common canopy trees along with species of Ficus, Alstonia, Celtis, Elaeocarpus, Canarium, Syzygium, Calophyllum, Didymocheton, Dysoxylum, Terminalia, and Sterculia. Understorey plants include the palms Licuala, Caryota, and Areca, bamboos, tree ferns (Cyathea sp.), Pandanus, and giant herbs. Bananas, gingers, lianas, and rattans grow forest gaps where sunlight reaches through the canopy. Epiphytes, particularly ferns and orchids, grow abundantly on the forest trees.
People
The first evidence of human inhabitation of the archipelago is at Kilu Cave on Buka, dating back 29,000 years ago to the Pleistocene. The settlers likely crossed the sea from the Bismarck Archipelago. At the time sea levels were lower, and New Ireland was separated from the Solomons by 180 km. The lower sea levels also joined several of the islands, including Buka, Bougainville, Choiseul, Santa Isabel, and the Florida Islands, into a single island known as Greater Bougainville or Greater Bukida.
Early settlers were likely highly mobile hunter-gatherers. Evidence from Kilu Cave show that early residents hunted bats, reptiles, rats, and birds from at least six families including several species of pigeon, a megapode, and a rail, along with marine shells and fish bones indicating inshore fishing. Residents also ate starches from taro (Colocasia esculenta) and Alocasia sp. The nut-producing trees Canarium indicum and Canarium salomonense were introduced to the Solomons from the New Guinea mainland about 10,000 years ago. Sea levels rose to close to current levels between 5500 and 6000 years before present (B.P.). Lapita settlers, the ancestors of today's Oceanic Austronesian peoples, arrived by 3400 B.P., and introduced the marsupial gray cuscus (Phalanger orientalis) to the islands.
1.2% of the ecoregion is in protected areas.
References
External links
- Solomon group endemic bird area (BirdLife International)