Sovi Basin (20332)
Fiji, Oceania
Site overview
KBA status: confirmed
Global KBA criteria: B2
Year of last assessment: 2007
National site name: Sovi Basin
Central coordinates: Latitude: -17.9167, Longitude: 178.2000
System: terrestrial
Elevation (m): 80 to 1185
Area of KBA (km2): 340.22245
Protected area coverage (%): 58.62
KBA classification: Global
Legacy site: Yes
Site details
Site description: Sovi Basin is a large basin or amphitheatre of low rolling hills ringed by steep volcanic peaks rising to 1,185 m. The hills in the western third of the basin are mostly between 300 m and 600 m, otherwise between 80 m and 300 m and drain through a narrow gorge to the east. The basin is composed of plutonic granite surrounded by andesite volcanics while the basin soils are infertile red-yellow podzols. Rainfall has been estimated at over 2,800 mm in the wet season (November–April) and 1,200—1,600 mm in the dry season, and lowland temperatures average 25°C.
Rationale for qualifying as KBA: This site qualifies as a Key Biodiversity Area of international significance that meets the thresholds for at least one criterion described in the Global Standard for the Identification of KBAs. KBA identified in the CEPF Ecosystem Profile of the Polynesia-Micronesia Hotspot (2007). Taxonomy, nomenclature and threat status follow the 2003 IUCN Red List.
Additional biodiversity: As the largest (proposed) protected area in Fiji, it supports the largest protected populations of many of Fiji’s restricted-range species. Further survey work is necessary to clarify the status of the Long-legged Warbler and of the 'missing' species, Red-throated Lorikeet. The nationally threatened Peregrine Falcon is often reported and is likely to breed. A1 Globally threatened species * Long-legged Warbler (EN) – three sightings (29–31 March 2005) * Friendly Ground-dove (VU) – uncommon * Black-faced Shrikebill (VU) – uncommon * Pink-billed Parrotfinch (VU) – generally rare but locally uncommon * Masked Shining Parrot (NT) – fairly common A2 Restricted-range species 24 species (out of 25 on Viti Levu), including all three endemic to Viti Levu. Non-bird biodiversity: The endemic Fijian Burrowing Snake (VU) is known historically from Sovi and several other endemic reptiles occur including Green Tree Skink and Fijian Copper-headed Skink. The Fijian Tree Frog (NT) also occurs. Recent PABITRA surveys suggest that the basin supports about 680 species of vascular plants, one third of Fiji’s total. This includes large numbers of Schefflera euthytrica (DD) in a very rare lowland rainforest formation on plains around creeks dominated by Verbenaceae trees.
Other site values: Sovi Basin is under traditional ownership of 13 mataqali, belonging to the three Tikina; Waimaro (97%), Nadaravakawalu and Namosi. As well as these Native Lands, there are eight small Crown Lands (totalling about 1,306 ha) and two Freehold Lands (80 ha). The basin was inhabited a few generations ago but abandoned because of poor soils and accessibility into the basin. Sovi is only 35 km from the capital, Suva.
Habitats
Summary of habitats in KBA: The outer boundaries of the IBA follow the edge of the contiguous dense forest, which includes the outer slopes of the basin. The Viti Levu Southern Highlands, is separated by the cultivated Waimanu valley, and the Rairaimatuku Highlands IBA is across patchy agriculture and degraded forest remnants to the north. The basin has 11 different lowland forest types, 45% of the wet forest types in Fiji. These are all old-growth forests except for small areas of previously cleared land along the main rivers. The canopy in the basin is about 20–25 m high with emergents up to 30 m, but is only 7–20 m high on the steep high-altitude slopes.
Land use: forestry | nature conservation and research
| IUCN Habitat | Coverage % | Habitat detail |
|---|---|---|
| Forest | 100 |
Threats
Summary of threats to biodiversity at KBA: Invasive alien species - Logging - Agriculture - mining
| Threat level 1 | Threat level 2 | Threat level 3 | Timing |
|---|---|---|---|
| Biological resource use | Logging & wood harvesting | Unintentional effects: large scale (species being assessed is not the target) [harvest] | Only in the past and unlikely to return |
| Invasive & other problematic species, genes & diseases | Invasive non-native/alien species/diseases | Named species | Ongoing |
| Natural system modifications | Fire & fire suppression | Increase in fire frequency/intensity | Ongoing |
| Energy production & mining | Mining & quarrying | Only in the future |
Additional information
References: BIRDLIFE INTERNATIONAL (2003) Fiji Programme IBA project field reports Nos 6, 7, 10, 14 and 32. CABANIUK, S., LEES, A. AND WRIGHT, S. (1995) A Future for the Sovi Basin, Waimaro – Integrating Conservation and Development. Final Report. Suva: Native Lands Trust Board. USP (2003) PABITRA Survey Report – Sovi Basin May 2003. Suva: University of the South Pacific. Unpublished report. USP (2004) PABITRA Survey Report – Sovi Basin October 2004. Suva: University of the South Pacific. Unpublished report.