The importance of the moss layer in sustaining biological diversity of Gamasina mites in coniferous forest soil

Summary The feather moss layer of boreal coniferous forests is known to buffer the underlying soil temperature and to be a major component in the nitrogen and phosphorus cycles by efficient scavenging of nutrients from throughfall and direct precipitation. Through indirect or direct effects the feather moss layer may also play a significant role in forming soil organism communities. In this 4-year experimental field study, the predatory Gamasina mite diversity was estimated in plots where the feather moss layer was removed or disturbed by turning over, in relation to that in control plots. Species richness, Shannon's diversity and equitability in spring but not autumn were decreased when the feather moss layer was removed. Those species that decreased in abundance and frequency tended to prefer the moss layer as opposed to the organic layer in control plots. The results suggest that the observed decline in diversity of the top carnivore microarthropod guilds was due mainly to a loss of moss habitat and not via changed abiotic conditions in the O horizon.