Cedrus libani: A promising tree species for Central European forestry facing climate change?

Abstract

Considering climate change, the discussion intensifies whether and to what extent exotic tree species should be taken into account for forest cultivation, especially when indigenous species are no longer able to fulfill essential forest functions. In this study, for the first time growth potential of Cedrus libani was evaluated under climatic conditions in Central Europe (Bayreuth, Germany). The sampled trees exhibited extraordinary growth with tree ring widths averaging 4.9 mm year -1 during the past 23 years. A continuously available soil water supply enhanced radial stem growth. Thus, growth declined during the dry year of 2003, but recovered to average values the following year. Our results confirm that C. libani is a lightdemanding species which is sensitive to competition and which shows a typical age trend. In a second study, we compared cambial growth in Bayreuth with a natural stand in Elmali (Turkey) in 2009. Cambial growing season in Bayreuth was 45 days longer, and radial growth rates in Bayreuth were four times higher than in Elmali. Interestingly, C. libani maintained a slow but continuous radial growth at Elmali even during the dry summer period, confirming its exceptional drought tolerance. Our results indicate a high adaption of C. libani to current and future climate conditions in Central Europe. It tolerates extreme cold in winter and prolonged droughts during summer. Thus, its promising potential for establishing stable and productive forest stands in Central Europe under a changing climate should be confirmed in further studies.

Environmental control of daily stem radius increment in the montane conifer Cedrus libani

“…The absence of soil water content in principal component analysis and the multiple linear regression model for trees at the O1 site may be due to the moist conditions and uniform water supply at the German site throughout the growing season in contrast to the Turkish sites. As noted by Messinger et al (2015), C. libani appears to adapt to climate conditions that prevail in Central Europe. Higher precipitation and relative humidity as well as lower temperatures during the growing season provide good growing conditions for C. libani.…”

“…The Turkish sites (T1-T4), were located within the Cedar Research Forest, District of Elmali, Antalya, a natural C. libani forest characterized by an oro-Mediterranean climate with cold winters and summer droughts (Senitza 1989;Basaran et al 2008). The German site (O1) was located within a C. libani plantation established in 1980 in the Ecological-Botanical Garden of the University of Bayreuth, Bavaria, and has a subcontinental climate with cold winters and warm summers (Messinger et al 2015). Point dendrometers were fixed to the trunks at breast height (1.3 m), with the outer bark carefully removed to minimize swelling and shrinking where the measuring head of the dendrometer was placed (Zweifel et al 2006).…”

“…and showed how SRI was positively correlated to rainfall. However, only few studies have investigated intra-annual growth dynamics on a daily basis from the montane Mediterranean region, although the area has species which, in the future, may complement indigenous species in Central Europe with regards to climate change (Messinger et al 2015). One of these potential species is Cedrus libani A.…”

“…Because of these characteristics, it is widely used in reforestation and afforestation projects in Turkey and in other countries (Boydak 2007;Ducci et al 2007). Messinger et al (2015) evaluated its potential to establish viable stands in Central Europe, underlining high adaptation of C. libani to current and future climatic conditions. With regards to its use in forestry and its adaptability, it is important to know more about stem growth dynamics of C. libani under different site and climatic conditions.…”

Planted forests and invasive alien trees in Europe: A Code for managing existing and future plantings to mitigate the risk of negative impacts from invasions

“…Discussion is intensifying in many countries on whether and, if so, then to what extent, alien tree species should be used for afforesta-tion, especially when native species are no longer able to fulfil essential forest functions. For example, in this regard, for the first time the growth potential of Cedrus libani was evaluated under climatic conditions in Central Europe (Bayreuth, Germany) by Messinger et al (2015).…”