Ecological indicator role of butterflies in Tam Dao National Park, Vietnam
Ecological indicator role of butterflies was assessed in Tam Dao National Park, Vietnam from May to October over three years from 2002 to 2004. The transect method was used to collect data. Thirty transects representing five different habitat types were set up at the altitude of 900-950 m a.s.l., from the natural closed forest to the agricultural land, with a length of 100 m for each transect. Indicator values were quantified for each butterfly family, genus, and species. The results showed no any butterfly family could be used as ecological indicator for the natural closed forest. Among many genera and species of butterflies recorded along thirty transects, only three butterfly genera and three butterfly species can be used as ecological indicators to assess the impact of disturbance on the natural closed forest. Genus indicators are Ragadia, Neope, Stichophthalma; species indicators are Ragadia crisilda, Neope muirheadi, and Stichophthalma howqua. Satyridae and Amathusiidae are characteristic butterfly families for the forest, but they are only can be used as ecological indicators for forest in general (the habitat inside forests, including the natural forest and the disturbed forest), not for natural forest. Although butterflies are sensitive to forest disturbance, very few butterfly species can be used as ecological indicators to assess the impact of disturbance on the natural closed forest.