Habitat associations of an Odonata community in a lower montane rainforest in Papua New Guinea

Abstract

I sampled odonates in pristine lower montane rainforest in Papua New Guinea over several months, recording habitat characteristics for all encounters with adult odonates. Using ordination techniques such as cluster analysis and canonical correspondence analysis I then classified the odonate fauna into assemblages correlated with environmental factors. Within the 2.5 km² study area I found 61 species and a very high ratio of Zygoptera vs Anisoptera. Cluster analysis identified seven distinct assemblages associated with permanent rivers and creeks, temporary streams, puddles, or permanent standing water. Shading, water speed and water permanence were important factors distinguishing the assemblages. Anisoptera were absent from three habitats in the forest interior with temporary water sources. Species associated with temporary water sources and other microhabitats in the forest interior are presumed to be reliant on the high and aseasonal rainfall and the humid conditions of the rainforest. These species are likely to be very intolerant towards deforestation or other disturbance, and should be regarded as indicators for intact rainforest ecosystems. 40% of all species were considered as rare, and local endemism might be high, further stressing the importance of intact rainforest for the survival of many species of Odonata.

Keywords: Odonata, dragonfly, dragonfly assemblage, habitat association, ordination, canonical correspondence analysis, Papua New Guinea

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