The ubiquitous soil-dwelling oribatid mites have long been investigated
as potential bioindicator agents for environmental changes, such as
those resulting from forest management. However, the oribatid community
composition often lacks detectable changes, mainly due to the
difficulties of finding homogenous microhabitats from the landscape for
investigation purposes. Red wood ant nest mounds in boreal forests,
however, form uniform, moisture, and temperature regulated,
microhabitats of which are also inhabited by a rather characteristic
oribatid fauna. With this standardized microhabitat—the red wood ant Formica aquilonia
nest mounds in Finland—we studied the impacts of forest clear felling
on the oribatid mites inhabiting those nests. We compared the oribatid
assemblages of altogether 41 ant mounds, located in three separate clear
fell areas and in adjacent mature coniferous forest. A total of 16,499
specimens, representing 67 oribatid species, were observed. The ten most
abundant species represented 90.9% of the total abundance. The oribatid
species richness was significantly lower in clear fell mounds and was
positively related to the surface moisture content of the mounds.
Oribatid abundance or community composition did not markedly differ
between clear fell and forest mounds. Despite the attempt to standardize
the microhabitat of oribatid fauna, the use of oribatid mites as
biological indicators of harvesting disturbance was limited with this
study design due the lack of changes in community composition. Then
again, the oribatid species richness of this characteristic microhabitat
may provide useable quality measures about the harms of forest clear
felling.