Experienced entomologist Erkki Laurinharju knows that beetle traps sometimes remain empty in commercial forests, but in UPM's Harviala forests this has never happened during the 12 years of the current research project. In fact, Laurinharju has found a great variety of beetles there, up to a third of Finland's 3,700 beetle species. Some of these are endangered.
An important attraction for beetles in Harviala is deadwood, an essential habitat for many beetle species. Harviala provides groups of burned trees and snags cut to 3 to 4 metres of length, allowed to decay and rot naturally. Previously artificial snags were usually aspen or spruce but the variety of tree types is greater in controlled burning areas.
“It is very interesting to watch how the species develop and evolve as the wood rots and softens,” remarks Laurinharju.
He expects to see examples of beetle species that favour decaying wood and that still exist in the southern Tavastia region. It is unlikely that any beetles would travel to Harviala from further afield.