Microclimate in hollow trees and how it affects an inhabiting beetle species, <scp> <i>Osmoderma eremita</i> </scp>

Studies of species' responses to microclimatic conditions have increased our understanding their habitat requirements and possible climate warming. However, little is known about the role microclimate for insects inhabiting hollow trees. We explored relationship between tree characteristics microclimate, analysed how in tree-hollows affects occurrence body size an endangered beetle species, Osmoderma eremita. placed temperature data-loggers wood mould (= loose material tree-hollows) surveyed O. eremita 47 hollows oak pastures south-eastern Sweden. found that previously be associated with species confined (larger diameters, more mould, entrances higher up, not directed upwards) tend decrease moisture variation, while effects on fluctuations differ during different seasons. This indicates are important beetles trees, many specialised seem avoid too moist. occurred frequently trees a warmer stable adult decreased microclimate. A positive effect was expected, since study done near northern margin range. living which may due there being comparison both ambient standing downed dead wood.