Mires and Peat (Sep 2015)
The fungal consortium of Andromeda polifolia in bog habitats
Abstract
(1) Andromeda polifolia (bog rosemary) is a common plant species in northern circumboreal peatlands. While not a major peat-forming species in most peatlands, it is characterised by a substantial woody below-ground biomass component that contributes directly to the accumulation of organic matter below the moss surface, as well as sclerophyllous leaf litter that contributes to the accumulation of organic matter above the moss surface. Rather little is known about the fungal communities associated with this plant species. Hence, we investigated the fungal consortium of A. polifolia in three distinct vegetation communities of ombrotrophic bogs near Khanty-Mansiysk, West Siberia, Russia, in 2012 and 2013. These vegetation communities were forested bog (Tr = treed), Sphagnum-dominated lawn (Ln), and Eriophorum-Sphagnum-dominated hummock (Er). (2) In total, 37 fungal taxa, belonging to five classes and 16 families, were identified and described morphologically. Seven fungal species were previously known from Andromeda as host. Others are reported for the first time, thus considerably expanding the fungal consortium of this dwarf shrub. Most taxa were saprobic on fallen leaves of A. polifolia found amongst Sphagnum in the bog. Two taxa were parasitic on living plant tissues and one taxon was saprobic on dead twigs. Three taxa, recorded only on A. polifolia leaves and on no other plant species or materials, may be host-specific to this dwarf shrub. (3) A quantitative analysis of the frequency of occurrence of all taxa showed that one taxon (Coccomyces duplicarioides) was very abundant, 64 % of the taxa occurred frequently, and 32 % of the taxa occurred infrequently. The mean Shannon diversity index of the community was 2.4. (4) There were no statistical differences in the fungal community composition of A. polifolia in the three vegetation communities investigated in this study. Redundancy analysis suggested that some fungal taxa were positively, and others negatively, correlated with the water level relative to the moss surface in the bog. (5) The information about the composition and structure of the fungal consortium of A. polifolia reported here could be supplemented using other techniques such as cultural and molecular methods. Nevertheless, the data presented improve our understanding of the different microbial communities functioning in peatlands and, thus, of carbon dynamics in these ecosystems.
