Dead standing pine trees in a boreal forest landscape in the Kalevala National Park

We examined and mapped the amount, structural features, site characteristics and spatial distribution of dead standing pine trees over a ten hectare area in an unmanaged boreal forest landscape in the Kalevala National Park in Russian Viena Karelia. After their death, Scots pine trees can remain standing for decades and sometimes up to 200 years, forming long-lasting and ecologically important structures in boreal forest landscapes. Standing dead pines decay very slowly and with time develop into ‘kelo’ trees, which are characterized by hard wood with silvery-colored appearance. These kelo trees represent an ecologically important, long lasting and visually striking element of the structure of natural pine-dominated forests in boreal Fennoscandia that is nowadays virtually absent from managed forest landscapes. See study here.

Above: Examples of different kelo structures contributing to forest structural and substrate diversity. (a) A fairly recently died partly debarked tree (often fall of bark is accelerated by woodpecker foraging). (b) Old kelo tree with fire scarring and charred wood in the trunk base. (c) A kelo with a cavity. The tree was made hollow by the Boreal Carpenter Ant (Camponotus herculeanus). (d) A large hollow broken kelo tree; such hollow broken trees are used for nesting by e.g. the Great Grey Owl. Photographs by Timo Kuuluvainen.