DENDROCLIMATIC RESPONSE OF LARCH AND BIRCH ACROSS AN ELEVATIONAL TRANSECT AND LARGE-SCALE CLIMATE COMPARISONS, KAMCHATKA PENINSULA, RUSSIAN FAR EAST

Kamchatka’s forests occurrence across the Peninsula’s diverse topography provides a wide range of elevational settings that can be used to investigate how tree growth varies with altitude. The information is vital for targeting zones and sites for dendroclimatic studies and for identifying changes in forests with warming climates. Stone birch (Betula ermanii Cham.) and larch (Larix cajandery Mayr.) were sampled at 8 sites from altitudes ranging from 70 to 950 masl, and together with previous collections were compared with monthly climate data. Comparisons show that tree-ring widths in both species are primarily influenced by May through August temperatures of the current growth year, and that there is an increased temperature sensitivity with altitude. Both the larch and birch data were also combined into regional chronologies and standardized using Regional Curve Standardization to enhance low-frequency variability. The resulting composite chronologies show a strong resemblance to Northern Hemisphere tree-ring based temperature reconstructions. The larch series tracks Northern Hemisphere temperatures well through the past 300 years, whereas the birch shows some deviations from the recent decades. These new data improve our understanding of the response of forests to climate and show that the low frequency warming noted in other, more continental records is also evident in the Kamchatka ring-width record.