Growth-climate responses of Picea sitchensis (Bong.) Carr. versus Picea abies (L.) Karst. in the British Isles and Central Europe

Introduced tree species have become increasingly important in the context of the ongoing climate change. This paper focuses on the dendrochronology of the most widespread introduced tree species in the British Isles – Sitka spruce (Picea sitchensis [Bong.] Carr.) – in comparable soil conditions in England, Czechia, and Slovakia. The research aims to evaluate the growth dynamics and the influence of climatic factors on this tree species while comparing it with economically main tree species in Europe – Norway spruce (Picea abies [L.] Karst.). Based on the analysis of 150 increment cores, the radial growth of Sitka spruce was on average 24.2% higher than that of Norway spruce. The highest increments in 52 to 62-year-old stands were achieved in England by both Sitka spruce (8.7mm) and Norway spruce (7.0 mm). In terms of negative pointer years (NPYs), there was no difference in the number of years with a significantly low increment between the two species at any site. The lowest effect of climatic factors on growth was found in Czechia, while the highest was in England. Higher resistance to climate was found for Sitka compared to Norway spruce. In general, the main limiting factor for the growth was the lack of precipitation in the previous year’s vegetation season, or heavy frost in England. In Central Europe, due to low precipitation, Sitka spruce will not be a substantial introduced tree species in the future, but on suitable sites, it can achieve high production potential and play a significant role for increasing stand diversity in the face of climate change.