This paper deals with choices of wood species in the 14th century polychrome sculptures in the diocese of Turku (Abo), Finland, the easternmost part of the Swedish Realm in the Middle Ages. The aim of the article is to draw an overall picture of the wood use in sculpture and discuss the emergence of the local workshops in the diocese. This is done by presenting new wood definitions and by taking these into account the when analysing the sculptures' style and form. The emphasis on the research is on sculptures previously defined as carved from birch and which thus are determined as Finnish or Nordic of their origin. The methods for defining the wood species have been ocular observation and microscopy analysis. The choice of wood is approached from the perspective of the wood species availability in the area and suitability for carving. The results of the investigation indicate that in addition to oak, and instead of birch, particularly alder (Alnus) was used in the locally manufactured sacral sculptures, and in some cases using oak sculptures as models. Alder was possibly favored due to its good availability and inexpensiveness as well as workability. It can, however not be ruled out, that sculptures of alder may have been imported to the bishopric as well.
