WETLAND SERVICES AND MANAGEMENT Composition and structure of macroinvertebrate communities in contrasting open-water habitats in Irish peatlands: implications for biodiversity conservation Edel Hannigan • Mary Kelly-Quinn Received: 13 December 2010 / Accepted: 17 March 2012 / Published online: 5 April 2012 Ó Springer Science+Business Media B.V. 2012 Abstract The purpose of this study was to consider the relative importance of several habitat variables in explaining the patterns in the structure of macroinver- tebrate assemblages in open-water habitats, in relatively intact bogs and fens, which should inform conservation strategies. It was hypothesised that variables relating to the size of the water body would differentiate the communities and that some species would be unique to certain conditions. The macroinvertebrate communities from pools [ 100 m 2 , 10.1–100 m 2 and Sphagnum hollows were characterised using sweep sampling for eight intact peatland sites across four bog types, and related to habitat variables including pool size, Sphag- num cover and hydrochemistry. Results showed com- munity composition and structure differed significantly between deep, permanent pools and shallow, drought- sensitive Sphagnum hollows, with larger invertebrates, such as Odonates and Dytiscinae, rarely found in the hollows. Sphagnum cover accounted for a substantial amount of the variation in community composition. An examination of life-history strategies found species dependent on predictable conditions for juvenile devel- opment to be more abundant in pools. In contrast, taxa that could delay juvenile development until conditions were favourable were more abundant in Sphagnum hollows. These results highlight the importance of habitat heterogeneity in maintaining macroinvertebrate diversity in peatlands. Keywords Macroinvertebrates Á Raised bog Á Blanket bog Á Fen Á Biodiversity Á Reference condition Introduction Raised and blanket bogs are listed for protection in Annex 1 of the EU Habitats Directive, meaning that intact peatlands must be conserved and those that are damaged and suitable for restoration, should be restored. In order to effectively protect or restore these priority habitats, there is a need to characterise their biodiversity and understand factors controlling their functioning and ecological integrity. Internationally, studies of aquatic macroinvertebrate communities have focused on the distribution of the communities of specific peatland types, and the controlling factors (Speight & Blackith, 1983; Larson & House, 1990; Downie et al., 1998; Guest editor: Chris B. Joyce / Wetland services and management Electronic supplementary material The online version of this article (doi:10.1007/s10750-012-1090-4) contains supplementary material, which is available to authorized users. E. Hannigan (&) Á M. Kelly-Quinn Freshwater Biodiversity, Ecology and Fisheries Research Group, School of Biology and Environmental Science, Science Centre West, University College Dublin, Belfield, Dublin 4, Ireland e-mail: edelhannigan@hotmail.com M. Kelly-Quinn e-mail: mary.kelly-quinn@ucd.ie 123 Hydrobiologia (2012) 692:19–28 DOI 10.1007/s10750-012-1090-4