The Mesostigmatid mite (Acari, Mesostigmata) community in canopies of Sitka spruce in Ireland and a comparison with ground moss habitats

J Arroyo,M L Moraza,T Bolger

doi:10.3989/graellsia.2010.v.66.007

Abstract

The main aim of this study was to examine the communities of mesostigmatid mites occurring in Irish Sitka spruce (Picea sitchensis) canopies or inhabiting moss, either in the canopy or on the soil surface, and to discover whether a characteristic assemblage of species occurs in particular habitat patches (ground vs. aerial). Twenty two species of Mesostigmata were recorded, of which five occurred exclusively in arboreal microhabitats. All three species of Zerconidae collected were unique to the canopy and moss mats on the tree branches. Trachytes aegrota (C.L. Koch, 1841) was recorded for the first time in Ireland and some comments about its distribution are made. Multivariate analysis indicated that the arboreal mesostigmatid community is not just a subset of the assemblage occurring in moss on soil or trunks and that it appears to be more homogeneous than those occurring on the soil surface.

Highlights

Materials and MethodsSitka spruce –Picea sitchensis (Bong.) Carr. (1832), a species native to North America, has been used widely for afforestation purposes in Ireland
Winchester (1997) points out that the distinct assemblage of oribatid mites inhabiting the canopy of coniferous trees in Western North America has been used as one of arguments for the conservation of these old-growth forests
The Detrented Correspondence Analysis (DCA) (Length of gradient for first axis: 2.88) ordination showed clear clusters related to habitats (Fig. 2) and this was especially evident for canopy microhabitat for both forests

Summary

Introduction

Materials and MethodsSitka spruce –Picea sitchensis (Bong.) Carr. (1832)–, a species native to North America, has been used widely for afforestation purposes in Ireland. (1832)–, a species native to North America, has been used widely for afforestation purposes in Ireland. It is chosen because it is a productive canopy species (Forest Service, 2000). The importance of researching in these habitats is highlighted by the fact that forest canopies support diverse arthropod assemblages, which are largely distinct from those on the forest floor (e.g. for mites Walter & Bellan-Pelletier, 1999). Winchester (1997) points out that the distinct assemblage of oribatid mites inhabiting the canopy of coniferous trees in Western North America has been used as one of arguments for the conservation of these old-growth forests

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Conclusion