Tree rings of Norway Spruce (Picea abies (L.) Karsten) in Lithuania as drought indicators : dendroecological approach

Dendrological research on the radial growth of Norway spruce in Lithuania during the 20th century has been conducted. Hypothesis of the study is following: intensity of droughts during the 20th century is the main factor determining the state of spruce forests in Lithuania. Aim of the study was to estimate the impact of dry spring and summer climate conditions on Norway spruce during the 20th century with a respect to global climate change. Climate impact on the radial growth of spruce using multivariate regression techniques and detection of pointer years (i.e. years with narrow tree rings in the majority of trees) was investigated. The results show that for radial growth of spruce the most important factor is humid beginning of summer and that from four to six pointer years to droughts during the 20th century are attributed.