Cedrus libani survival and growth data from a transplant experiment and natural forests in northern Lebanon

Aims The Cedrus dataset was set up to assess the climatic niche breadth
of Cedrus libani – a relict mountain species – by comparing field
observations and transplant experiment measurements within and beyond the
elevational range limits of Cedrus under natural conditions. Location
Lebanon - Near East - Mediterranean region Methods The transplant
experiment included 8 common gardens at altitudes ranging from 110 to 2330
m, within and far beyond the warm and cold limits of Cedar distribution
under natural conditions. It was set up in 2018, and monitored for three
years until fall 2021 to study survival and growth of the Cedar of Lebanon
(Cedrus libani) and 3 potentially competing species (Quercus calliprinos,
Quercus infectoria and Pinus brutia). Field observations of Cedar
presence/absence were carried out on 1023 sites. Results We observed
surprisingly high survival and growth rates of Cedar at elevations well
below its natural range in Lebanon. Below its elevational limit of 1300 m
under natural conditions, water stress limited the survival of juvenile
Cedars at elevations below 500 m, and its low competitiveness below 900 m
explained its absence between 500 and 900 m elevation. On the other hand,
cold temperature and water stress limited its survival at elevations
slightly above the observed natural upper elevational limit of 1830 m.
Main conclusions The experimental setup demonstrated that the elevational
range suitable for the growth and survival of the Cedar of Lebanon is
twice as large as the range within which Cedar is observed today under
natural conditions. The high survival rate beyond the lower limit of its
natural range raises hope for its resilience to ongoing climate warming.
If this pattern were common to other mountain species, it would challenge
predictions of massive extinction linked to climate change, and pave the
way for promoting adaptive actions such as competition management to
improve their survival.