Klippel, L.,* Hartl-Meier, C., Lindén, J., Kochbeck, M., Emde, K. and Esper, J. 2017. Hourly Resolved Climate Response of Picea abies beyond its Natural Distribution Range. Baltic Forestry 23(3): 556-563.

   Norway spruce (Picea abies (L.) Karst.) is an economically significant species of timber industry in Germany. However, previous studies reported a drought sensitivity of spruce questioning the suitability of this species when exposed to future climate change. We analyse the species’ climate sensitivity by comparing high-resolution stem radius changes of four spruce trees with prevailing weather conditions from April 2012 to December 2014. The study is based on dendrometer data recorded in the Taunus (Germany) in a forest plantation beyond the species natural distribution range. The sub-hourly dendrometer data are decomposed to emphasize diurnal growth patterns and compared with related weather patterns. Our results show that both climate and photoperiod control the timing of spruce growth. Daily radial changes are best explained by relative humidity and temperature variations, but a distinct precipitation signal is not detected. The missing precipitation response is likely related to well-developed Stagnosols at the sampling site in the Taunus preventing transpiration stress to occur. These findings suggest that a balanced water supply attenuates the trees’ climate sensitivity even beyond the species natural distribution range and highlights the significance of site selection in plant performance assessments.

   Keywords: climatic stress, dendroecology, dendrometer, diurnal cycle, Norway spruce, radial growth