Are there any differences between taxa groups having distinct ecological traits based on their responses to environmental factors?

Abstract

The aim of this study was to explore the differences between taxa groups with different ecological strategies for persistence, regarding their responses to environmental factors and seasonal variation. We studied the relationship between the seasonal patterns and habitat attributes of the Ephemeroptera, Plecoptera, Trichoptera (EPT) and the Colepotera, Heteroptera (CH) assemblages. Sampling was carried out in May, July and October of 2009. Samples were taken according to the AQEM protocol at 10 stream sections in the Mecsek Mountains. Based on multivariate analyses (RDA, pRDA), distinctive differences were found between the EPT and the CH taxa groups regarding their response to local chemical variables and variables describing the riparian vegetation. The measured environmental variables had a higher relative influence on the distribution patterns of EPT and CH assemblages than spatial variation of species patterns. The physical structure of aquatic habitats, including the type of bedrock, had greater effects on CH than EPT patterns, whereas the structure of riparian vegetation was more important for EPT than CH. Average density and average taxon richness of EPT were seasonally variable, but CH assemblages were not.

Keywords:

• aquatic insect assemblages
• near-natural headwaters
• environmental variables
• spatial and seasonal distribution
• Partial Redundancy Analysis

Acknowledgements

We would like to thank Csaba Deák, Zoltán Kálmán and Nándor Soós for their help in identification of mayflies, stoneflies, aquatic beetles and aquatic and semi-aquatic bugs and the students of the University of Pécs for help in field and laboratory works. We thank Thomas G. Horvath, Csaba Bereczki, Zuzana Pastuchová and an anonymous reviewer for their valuable comments on manuscript.