Constraints on dendrochronological dating of Salix polaris from central Spitsbergen ( Short communication )

Abstract

Application of tundra shrubs in dendrochronological studies is recently increasing. However their growth rings are characterized by high irregularity which cause a com-mon tree-ring dating problems. The goal of the study is to demonstrate a dendro-chronological potential of common tundra species Salix polaris from central Spitsbergen (Ebbadalen, Petuniabukta) while (i) presenting its radial growth pattern and irregularities and (ii) discussing on its example a common problems of Arctic shrubs radial growth cross-dating. The results revealed that in average 25% of growth ring measured per single shrub was irregular and therefore might be problematic to detect and cross-date. It was found that even on a short distance (i.e., along a main root axis) cambial activity is not equal and missing and partially missing rings occurred alternately in a longitudinal profile. Common growth irregularities, such as missing and wedging rings, must be taken into account while measuring and cross-dating such a difficult dendrochrono-logical woody material as shown on the example of a Salix polaris dwarf shrub. The study revealed a high importance of serial sectioning and intra-plant cross-dating in dendrochronological studies of tundra shrubs.