DOI: 10.5061/dryad.k0p2ngfdf
title: Cedrus libani survival and growth data from a transplant experiment and natural forests in northern Lebanon

description: 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.
description: <strong>Distribution of Cedar in natural
 conditions</strong> To assess the altitudinal
 distribution of the Cedar of Lebanon in the natural conditions of northern
 Lebanon, we recorded its presence/absence in 1023 sites located outside
 urban areas and plantations, i.e., in 750 field vegetation surveys and 273
 high-altitude sites with a low tree cover visually checked for its
 presence using satellite imagery. This dataset was used to define the
 elevational range of the sites harboring Cedar. The lower and upper range
 limits of Cedar under natural conditions were defined by the
 5<sup>th</sup> and 95<sup>th</sup> quantiles of
 the elevational distribution of Cedar occurrences (Stahl et al.,
 2014). <strong>Survival and growth in the
 transplant experiment</strong> A transplant
 experiment was set up in northern Lebanon along Kadisha Valley. This
 region is at the heart of the geographical range of Lebanese Cedar
 populations, where a 0-3000 m elevational gradient can be covered within a
 few tens of km. Given that the altitudinal distribution of Cedar provided
 by the literature extends between altitudes of approximately 1100 and 1950
 m (Khuri et al., 2000), eight experimental sites were established at
 regular intervals between 110 and 2320 m elevation to test for Cedar
 fitness, starting from the middle of the range and then up and down to the
 cold and warm limits of the range and far beyond. Table
 ‘B2_ExpSites_Clim.csv’ provides the key climatic parameters of each
 experimental site.  Common gardens were established on
 sites with optimal soil conditions, chosen to highlight the effects of
 climate in the absence of edaphic constraints. Since the Cedar of Lebanon
 grows essentially on calcareous or calcaro-dolomitic substrates (Boydak,
 2003), the common gardens were located in a calcareous environment (except
 the site located at 970 m altitude) on deep (&gt; 40 cm) plowed soils
 cleared of large stones and with a predominantly clayey texture. The
 effects of exposure and slope were minimized by selecting sites in
 topographic situations with a slope of less than 3% (except for the two
 sites located at high altitudes). As the Cedar of Lebanon is a
 heliophilous species (Boydak, 2003), the sites were located in full light.
 They were also covered with canvas and gravel and regularly weeded
 manually to avoid competition from herbaceous species. A water tank was
 installed at each site for plant watering. Finally, all the sites were
 protected from grazing by an enclosure, except the two high-altitude sites
 located in ungrazed, supervised areas. Cedar seeds were
 collected in April-May 2018 from natural stands at the low (1232 m a.s.l),
 middle (1431 m a.s.l.) and high (2011 m a.s.l) elevational limits of its
 distribution range in northern Lebanon. Seeds of the three competing
 species of Cedar under natural conditions –- <em>P.</em>
 <em>brutia</em>, <em>Q. calliprinos </em>and
 <em>Q. infectoria </em>–<em> </em>were also
 collected at the low and high altitudinal limits of each species’ range in
 natural forests in northern Lebanon and in mid-range, at the same period
 as Cedar for pine, and in November-December 2017 for the two oak species.
 Seeds of cedar and the other species were planted in pots immediately
 after harvesting. All seedlings were transplanted to the experimental
 sites in fall 2018. Each site was composed of two batches: a non-watered
 batch representative of natural conditions, and a control batch watered
 during the summer period to study seedling survival and growth in the
 absence of water stress. Seedlings of the four species
 were planted in the batches with a constant spacing of 50 cm to allow them
 to grow freely until the juvenile stage. Seedlings from low, medium, and
 high altitudes were distributed evenly between the sites and treatments:
 12 trees <em>per </em>provenance<em>
 </em>and<em> </em>species were planted in each ‘watered’
 treatment <em>per</em> site (72 seedlings
 <em>per</em> species in each common garden and 576 seedlings
 <em>per</em> species altogether). The
 experiment lasted 3 years – from fall 2018 (planting) to fall 2021 (last
 measurements). To ensure seedling recovery after transplanting, both the
 watered and non-watered batches were watered in 2019 during the first
 growing season after transplanting. Watering was discontinued for the
 non-watered seedlings after the first rains in the fall of 2019, whereas
 the ‘watered’ seedlings were watered with 13.9 liters of water twice a
 month during spring and summer in 2020 and 2021. Tree
 height, diameter at the base of the stem, and survival were measured in
 October of each year, after the growing season. These measurements were
 used to calculate survival rates and average growth in diameter and height
 at each site and for each species and watering treatment.
 As dimensions of competition were not all measurable, we focused
 on early growth indicators as proxies of inter-species competition. The
 competitiveness of Cedar along the altitudinal gradient was analyzed by
 comparing its growth in each common garden with that of its competitors
 (<em>Q. calliprinos, Q. infectoria and P. brutia</em>) planted
 at the same elevation and in the same conditions (Gaudet & Keddy,
 1988; Westoby et al., 2002; Tanner et al., 2005).
 <strong>References</strong>
 Boydak, M. (2003) Regeneration of Lebanon cedar (Cedrus libani A.
 Rich.) on karstic lands in Turkey. Forest Ecology and Management, 178,
 231-243. Gaudet, C.L. & Keddy, P.A. (1988) A
 comparative approach to predicting competitive ability from plant traits.
 Nature, 334, 242-243. Khuri, S., Shmoury, M.R.,
 Baalbaki, R., Maunder, M. & Talhouk, S.N. (2000) Conservation of
 the Cedrus libani populations in Lebanon: history, current status and
 experimental application of somatic embryogenesis. Biodiversity and
 Conservation, 9, 1261-1273. Stahl, U., Reu, B.
 & Wirth, C. (2014) Predicting species' range limits from
 functional traits for the tree flora of North America. Proceedings of the
 National Academy of Sciences of the United States of America, 111,
 13739-13744. Tanner, E.V.J., Teo, V.K., Coomes, D.A.
 & Midgley, J.J. (2005) Pair-wise competition-trials amongst
 seedlings of ten dipterocarp species; the role of initial height, growth
 rate and leaf attributes. Journal of Tropical Ecology, 21,
 317-328. Westoby, M., Falster, D.S., Moles, A.T., Vesk,
 P.A. & Wright, I.J. (2002) Plant ecological strategies: Some
 leading dimensions of variation between species. Annual Review of Ecology
 and Systematics, 33, 125-159.
description: Data files can be opened with Excel or R.
description: # Cedrus libani* survival and growth data from a transplant experiment and
 natural forests in northern Lebanon** ## **Description of the data and
 file structure** The Cedrus database (v.1.0) contains data from two
 complementary approaches: (i) observations of Cedrus libani
 presence/absence in natural forests of northern Lebanon; and (ii)
 measurements from a transplant experiment of Cedrus libani and three other
 species in 8 common gardens at elevations ranging from 110 m to 2330 m,
 far exceeding the warm and cold limits of the range of Cedar under natural
 conditions. The data files are the following ones: (i) One csv-file
 (A1_CedrusPA) with data about the presence/absence of Cedar in 1023 sites
 in the mountains of northern Lebanon located outside urban areas and
 plantations, including 750 plots observed in the field and 273 sites
 photo-interpreted on satellite images in stands with a low tree cover
 (most often at high elevation). Elevation, mean annual temperature, mean
 annual precipitation, mean minimum temperature of January and mean
 precipitation from July to September are provided for each of the 1023
 plots. Climate data were extracted from CHELSA v2 database (Karger et al.,
 2017) at 1-km resolution and averaged for the 1981-2010 period. (ii) Two
 csv-files (B1_Cedrus_2mod, B2_ExpSites_Clim) with the climate
 characteristics of the 8 common gardens of the experimental setup
 (B2_ExpSites_Clim) and measurements of mortality, radial growth and height
 growth of Cedrus libani, Quercus calliprinos, Quercus infectoria and Pinus
 brutia at the juvenile stage, carried out in the 8 common gardens
 (B1_Cedrus_2mod). The eight sites covered a 2200 m elevation gradient in
 the mountains of northern Lebanon and included a ‘watered’ treatment and a
 ‘non-watered’ treatment. Cedar and Pine seeds were collected in April-May
 2018. Oak seeds were collected in November 2017. Seeds were collected at
 the lower, medium, and upper parts of the elevational range of each
 species. They were planted in pots immediately after harvesting. All
 seedlings were transplanted to the experimental sites in fall 2018.
 Seedlings from low, medium, and high elevation were distributed evenly
 across the sites and treatments. Survival and growth measurements were
 carried out in fall 2021. ## **Legends** ### (i) Observations in natural
 Cedrus libani forests **A1_CedrusPA**: cvs file with 1023 rows and 9
 fields:  ID, site ID; Longitude, site longitude [decimal degrees];
 Latitude, site latitude [decimal degrees]; Cedrus.libani.PA,
 presence-absence observations of Cedrus libani with 1=presence and
 0=absence; Elevation, elevation [m a.s.l.]; Annual.temperature, mean
 annual temperature [°C]; Annual.precipitation, mean annual precipitation
 [mm]; Min.Temperature.Jan, mean minimum temperature in January [°C];
 Precipitation.JulytoSept, mean precipitation in July - September [mm]. ###
 **(ii) Experimental sites** **B1_Cedrus_2mod**: csv-file with 2304 rows
 and 7 fields: PlantID, seedling ID; Elevation, site elevation [m a.s.l.];
 Treatment, watering treatment with 2 conditions (‘watered’,
 ‘non-watered’); sp, four measured species: Celi (*Cedrus libani*), QuCa
 (*Quercus calliprinos*), QuIn (*Quercus infectoria*), and Pibr (*Pinus
 brutia*); Mortality, seedling mortality: 0= alive, 1=dead;  Height_A2021,
 seedling height (mm); Diameter_A2021, seedling diameter (mm). If seedlings
 have not been measured because they were dead, the Height_A2021 and
 Diameter_A2021 variables, take an NA. **B2_ExpSites_Clim**: csv-file with
 8 rows and 8 fields: ID, common garden ID; Longitude, site longitude
 [decimal degrees]; Latitude, site latitude [decimal degrees]; Elevation,
 common garden elevation [m a.s.l.]; Annual.temperature, mean annual
 temperature [°C]; Annual.precipitation, mean annual precipitation [mm];
 Min.Temperature.Jan, mean minimum temperature in January [°C];
 Precipitation.JulytoSept, mean precipitation in July - September [mm]. ##
 Sharing/Access information Climatic time series were obtained from the
 following source:
 [https://chelsa-climate.org/chelsacruts/](https://chelsa-climate.org/chelsacruts/)