title: Forest plant and bird communities in the Lau Group, Fiji.
abstract: BACKGROUND
  We examined species composition of forest and bird communities in relation to environmental and human disturbance gradients on Lakeba (55.9 km²), Nayau (18.4 km²), and Aiwa Levu (1.2 km²), islands in the Lau Group of Fiji, West Polynesia. The unique avifauna of West Polynesia (Fiji, Tonga, Samoa) has been subjected to prehistoric human-caused extinctions but little was previously known about this topic in the Lau Group. We expected that the degree of human disturbance would be a strong determinant of tree species composition and habitat quality for surviving landbirds, while island area would be unrelated to bird diversity.
  
  
  RESULTS
  All trees > 5 cm diameter were measured and identified in 23 forest plots of 500 m² each. We recognized four forest species assemblages differentiated by composition and structure: coastal forest, dominated by widely distributed species, and three forest types with differences related more to disturbance history (stages of secondary succession following clearing or selective logging) than to environmental gradients (elevation, slope, rockiness). Our point counts (73 locations in 1 or 2 seasons) recorded 18 of the 24 species of landbirds that exist on the three islands. The relative abundance and species richness of birds were greatest in the forested habitats least disturbed by people. These differences were due mostly to increased numbers of columbid frugivores and passerine insectivores in forests on Lakeba and Aiwa Levu. Considering only forested habitats, the relative abundance and species richness of birds were greater on the small but completely forested (and uninhabited) island of Aiwa Levu than on the much larger island of Lakeba.
  
  
  CONCLUSIONS
  Forest disturbance history is more important than island area in structuring both tree and landbird communities on remote Pacific islands. Even very small islands may be suitable for conservation reserves if they are protected from human disturbance.
authors.affiliation: School of Geographical Sciences and Urban Planning and School of Life Sciences, Arizona State University, Tempe, Arizona, United States of America.
authors.forename: Janet
authors.initials: J
authors.lastname: Franklin
authors.forename: David W
authors.initials: DW
authors.lastname: Steadman
mesh_terms: D000818:Animals; D001717:Birds / Q000502:physiology*; D017753:Ecosystem; D004777:Environment; D005367:Fiji; D005843:Geography; D018521:Plant Physiological Phenomena; D010944:Plants / Q000378:metabolism*; D011157:Population Dynamics; D014197:Trees