The abundance and diversity of Odonata along an altitudinal gradient in East Java']Java, Indonesia

Odonate diversity in East Java was surveyed, and samplings were made during 2 years in ten sites along an altitudinal gradient. The characteristics of odonate assemblages in East Java were analyzed regarding of the number of individuals, the number of species, and Shannon's diversity index. The differences in abundance, species richness, and diversity between study sites were analyzed by an independent t-test. There were 3270 individuals of Odonata belong to 30 species, 7 families and 2 suborders identified from all study sites. The abundance, species richness and diversity of Odonata varied between study sites. The greatest abundance of Odonata was found in Malang Coban Talun (MCT) (148.8 +/- 9.5), while the lowest was in South Beach Forest (SBF) (14.4 +/- 3.6). The highest species richness and diversity was found in Malang Paddy Field (MPF) (richness = 14.4 +/- 0.8 and H' = 2.4 +/- 0.1), while the lowest was found in South Coastal Area (SCA) (richness = 2.8 +/- 0.1 and H' = 0.4 +/- 0.1). A significant positive correlation was detected between the elevation and overall odonate abundance (P < 0.05), while there was not significant correlation between that and odonate species richness and diversity.