WOODPECKER ASSEMBLAGES IN NATURAL AND MANAGED BOREAL AND HEMIBOREAL FOREST - A REVIEW

Woodpecker species as a group require several properties (dead wood, o ld deciduous and large trees) that are characteristic of natural fores t, the presence of which are not compatible with intensive forest mana gement. The occurrence of many woodpecker species may thus indicate a high degree naturalness of forests. Using woodpeckers as indicators re quires that we understand how these species were distributed in natura lly dynamic landscapes, as well as quantitative knowledge of their req uirements. We review the basic biology of boreal/hemiboreal woodpecker s and compare the degree of specialization of the different woodpecker species with their population trends and with changes in habitat dist ribution in the boreal/hemiboreal landscape over the last century. The comparison shows that there is a close connection between the degree of specialization of woodpeckers, the changes in forests and recent po pulation trends. Thus woodpecker species as a group are in conflict wi th intensive forest management. To keep viable populations of all wood pecker species in a landscape existing values must be preserved and na tural features be built into future forests. Future research should in clude studies of distribution, abundance, habitat niche breadth and fi tness of different woodpecker species in landscapes with different deg rees of naturalness.