Impact of climatic conditions on radial growth of non-native Cedrus libani compared to native conifers in Central Europe

Ongoing climate change increasingly affects growth conditions of native conifers such as Picea abies (Norway spruce) and Pinus sylvestris (Scots pine) in Central Europe. These conifers are primarily cultivated for wood production. To obtain ecologically and economically stable forests, forestry seeks alternative species that might be less prone to novel climatic conditions, such as Cedrus libani (Lebanon cedar). We aim at investigating growth responses to climatic factors of C. libani compared to native P. abies and P. sylvestris in Central Europe for 25 years (1994-2019). Growth responses were used as a proxy for tolerance towards climatic stress events, such as heat and drought. Height, diameter at breast height (DBH) and radial increment were measured for 40-year-old tree stands of C. libani and native conifers. Radial growth responses to selected climate parameters were analysed using bootstrapped correlations with detrended growth index chronologies and growth response indices for drought years (2003, 2012, 2015, 2018). For C. libani, radial growth was positively correlated with high water availability in late winter and spring, while for P. abies, February and summer and for P. sylvestris, July showed such a relationship. Cedrus libani exhibited the highest resistance, recovery, and resilience in response to climatic extremes. Against the background of climate change, C. libani could serve as an alternative conifer species to establish climate-resistant viable forests in Central Europe.

Automated summary

Ongoing climate change is affecting the growth conditions of native conifers in Central Europe, leading to the exploration of alternative conifer species that are more tolerant to novel climatic conditions. Cedrus libani (Lebanon cedar) showed the highest resistance, recovery, and resilience to climatic extremes compared to native Picea abies (Norway spruce) and Pinus sylvestris (Scots pine). The study analyzed growth responses of these tree species to climate parameters over a period of 25 years to identify their tolerance towards climate stress events.