Cedrus Libani Research Articles

Contribution à l’amélioration de la germination chez une endémique forestière du Maroc, le cyprès de l’Atlas

La cupressacée à Cupressus atlantica, qui abrite une diversité biologique originale, joue un rôle socio-économique et écologique important. Cependant, ces formations, souvent présteppiques, sont soumises à des pressions croissantes d’origine principalement antropique. En outre, d’autres facteurs tels que la sécheresse, l’absence de régénération ou encore les ravageurs des cônes et des graines, menacent à terme l’avenir du cyprès de l’Atlas. Actuellement, les services forestiers marocains adoptent des orientations qui consistent à utiliser de plus en plus des espèces autochtones, notamment le Cyprès atlasique, dans les programmes de reboisement. Ainsi, il est très important de maîtriser l’itinéraire technique de production des plants de qualité. Cela nécessite une intensification des efforts en matière de recherche pour améliorer les connaissances des différentes étapes de ce processus, depuis la collecte des semences jusqu’à l’acclimatation des plants en passant par le stockage et la germination des graines. La présente étude vise à apporter une contribution concernant le comportement germinatif de ce conifère. En premier lieu, plusieurs traitements de prégermination (traitement chimique, traitement par l’eau à différentes températures, traitement mécanique qui consiste à frotter les graines avec du papier à sable) ont été expérimentés afin d’améliorer la germination par la levée de la dormance des graines. Les résultats relatifs à ces prétraitements ont montré que ces derniers jouent un rôle primordial dans la levée de la dormance et améliorent par conséquence la germination. En effet, les taux de germination les plus élevés 67,77 % et 75,55 % ont été enregistrés respectivement au niveau des graines traitées avec de l’eau chaude (60 oC) et par la scarification mécanique. Le traitement avec de l’acide sulfurique concentré a conduit à des taux de germination très faibles voire nuls, contrairement à ce qui a été observé chez d’autres espèces forestières et à ce qui avait été précédemment reporté chez le Cyprès atlasique. C. atlantica possèdent une dormance physique attribuée au tégument dur, qui peut entraver la régénération naturelle. La scarification mécanique et l’eau chaude (60 oC) sont les traitements les plus efficaces pour améliorer la germination des graines du C. atlantica. Le stress hydrique et le stress salin ont un effet inhibiteur sur la germination des graines du cyprès de l’Atlas. Ces résultats, concernant la germination, premier maillon de l’opération de reboisement, peuvent contribuer à la restauration des espaces dégradés et la réhabilitation des écosystèmes aride et semi-aride.

Succession of epiphytic bryophytes in Cedrus libani forest on the Meydan Plateau (Aladağ)

The succession of epiphytic bryophytes was investigated in Cedrus libani A.Rich. forest on the Meydan Plateau (Aladağ). A total of 19 taxa (16 mosses, 3 liverworts) were recorded in 90 sampling relevés, 4 dm^2 each. Index of ecological significance (IES) was used to evaluate the ecological importance of the taxa in epiphytic habitats on tree trunks. Additionally, the epiphytic bryophyte succession of the cedar forest was analysed using multivariate classification techniques (TWINSPAN and DECORANA). The multivariate analysis results showed that the epiphytic bryophyte communities were divided into 2 main groups and 5 different subgroups associated with successional gradient. Moreover, habitat affinities of the taxa and their life forms were evaluated along a gradient of height and the gradient of age of the host tree. Tortella tortuosa, Syntrichia ruraliformis, and Bryum capillare were only found on young trees, Zygodon rupestris only on middle-aged trees, and Pterigynandrum filiforme on aged trees.

The effects of temperature for development time, fecundity and reproduction on some ornamental aphid species

The development time, survivorship and reproduction of the Sarucallis kahawaluokalani (Kirkaldy), Eucallipterus tiliae L., Capitophorus elaeagni del Guercio, Aphis nerii Boyer de Fonscolombe, Cinara cedri Mimeur were studied on the Lagerstroemia indica L., Tilia tomentosa Moench, Elaeagnus angustifolia L., Nerium oleander L. and Cedrus libani Loud. at four constant temperatures (20C, 22.5C, 25C and 27.5C). Total nymphal development time ranged from 7.78 d at 22.5C to 9.81 d at 25C of C.elaeagni, 9.32 d at 25C to 12.5 d at 20C of E. tiliae, 7.08 d at 27,5C to 11.14 d at 20C of S. kahawaluokalani, 15.85 d at 25C to 12.57 d at 20C of A. nerii and 13.00 d at 20C to 10.07 d at 25C of C. cedri. The intrinsic rate of increase (rm) at 22.5C had the highest value for S. kahawaluokalani and C. elaeagni (0.5703) and (0.2945) among all tested constant temperatures. The calculated rm was higher at 25C for E. tiliae (1.4124) and C. cedri (0.2975) and at 20C A. nerii (0.2648). That the optimal temperature for E. tiliae and C.cedri on T. tomentosa and C. libani was 25C, for C. elaeagni and E. tiliae was 22.5C on E. angustifolia and T. tomentosa and for A. nerii was 20C on N. oleander.

Phytochemical Analysis and Cytotoxicity Towards Multidrug-Resistant Leukemia Cells of Essential Oils Derived from Lebanese Medicinal Plants

Juniperus excelsa fruit essential oil as well as J. oxycedrus, Cedrus libani, and Pinus pinea wood essential oils have been obtained with yields between 2.2 ± 0.3 % to 3.4 ± 0.5 % and analyzed by gas chromatography. Sesquiterpenes mainly characterized C. libani and J. oxycedrus essential oils, while in P. pinea and J. excelsa, monoterpenes were the most abundant compounds. In J. oxycedrus, cis-calamenene (7.8 %), cuparene (3.8 %), and cis-thujopsenal (2.0 %) have been detected for the first time. The cytotoxic activity of these essential oils against drug-sensitive CCRF-CEM and multidrug-resistant P-glycoprotein-expressing CEM/ADR5000 leukemia cells has been investigated (IC₅₀ values: 29.46 to 61.54 µg/mL). Remarkably, multidrug-resistant CEM/ADR5000 cells did not reveal cross-resistance, indicating that these essential oils might be useful to treat otherwise drug-resistant and refractory tumors.

Relationships among Cedrus libani, C. brevifolia and C. atlantica as revealed by the morphological and anatomical needle characters

The main aim of the present study was testing the value of the morphological and anatomical characteristics of the needles in distinguishing Cedrus atlantica, C. libani and C. brevifolia. Nine populations were sampled in their natural habit and 25 characters were used to describe the variation of the brachyblast needles and to analyze the differences between species. The results indicated that morphological and anatomical needle characters provide valuable tools in discrimination of the taxa. The scored differences were statistically significant, as revealed in the Tukey’s t test, discrimination analysis and hierarchical analysis of variation. The results support treating C. libani, C. atlantica and C. brevifolia as independent species.

Göller Yöresinde yalancı akasya, Anadolu karaçamı ve Toros sediri ağaç türleri için çap-boy modeli

The height of a tree is important for assessing tree volume and site index. Diameter of breast height-tree height releation equations are often used to predict the mean tree height for trees in case only diameter at breast height is measured. This study aim describes between the tree heights with diameter of breast height relationships for artificially grown black locust (Robinia pseudoacacia L.), Anatolian black pine (Pinus nigra Arnold. subsp. pallasiana (Lamb.) Holmboe) and Taurus cedar (Cedrus libani A.Rich.) in Lakes Region. It's presented a set of height-diameter equations for four tree species using data obtained from artificially grown stands in Lakes Region. Monserud's (1975) equation is used bacause of this equation is a flexible form that readily fits many height-diameter datasets. Nonlinear regression techniques were used to test the equation. The resulting equations provide a reasonable means of predicting unknown tree heights, given diameter of breast height, for Black locust, Anatolian black pine and Taurus cedar tree species in Isparta and Burdur Regions. This height-diameter equation can be used to avoid time-consuming task of measuring heights of all individual trees in inventory for this species. Keywords: Height-diameter equation, Allometric equation, Non-linear model, Lakes region

Physiological and growth responses of Cedrus libani seedlings to cold storage

The effects of cold storage duration on the physiological characteristics and growth of two-year-old Taurus cedar (Cedrus libani A. Rich) seedlings were studied. Taurus cedar seedlings were lifted in December, January and February and stored at +4 °C (cold storage) for 0, 2, 3 and 4 months. Xylem water potential (Ψ), shoot (SMC) and root moisture (RMC) contents, root growth potential (RGP), root electrolyte leakage (REL) and total carbohydrate contents were determined before and after the cold storage. The survival and growth were also evaluated at the end of the first growing season. Ψ, SMC and RMC, RGP and total carbohydrate contents were dramatically affected by the storage duration. The decrease in total carbohydrate contents during the storage showed a parallelism with RGP and survival. It was also found that storage duration had important effects on survival and growth. While survival was above 85 % even after storage of 4 months in seedlings that were lifted in December and January, this rate was reduced to 30 % after storage of 4 months in seedlings that were lifted in February. Total carbohydrate content and RGP can be used as an indicator of survival after cold storage.

The Forest Floor and Mineral Soil Carbon Pools of Six Different Forest Tree Species

The influence of tree species on forest soil properties has been studied for a long time. Recently, the role of soil carbon (C) pools for mitigation of greenhouse gases has highlighted the need for more knowledge on the tree species effects on soil organic C. In Turkey, the effects of six different tree species; Sessile oak (Quercus petraea), Oriental spruce (Picea orientalis), Austrian pine (Pinus nigra), Turkish fir (Abies bormulleriana), Scots Pine (Pinus sylvestris), and Taurus cedar (Cedrus libani) on the carbon pools of the top mineral soil (0-30 cm) and the forest floor were investigated in adjacent stands. Carbon pools of the forest floor varied from 11 Mg ha -1 beneath the Oriental spruce to 20 Mg ha -1 beneath the Scots pine. The C contents of the forest floor were similar among species and there was no significant difference in C mass of forest floors among species. In the 0-30 cm mineral soil layer, the highest soil organic C pool was beneath the Taurus cedar and the lowest was found in the native Sessile oak forest. Total C pools (forest floor + 30 cm mineral soil) increased in the order Quercus petraea < Abies bornmulleriana < Picea orientalis < Pinus sylvestris < Pinus nigra and Cedrus libani from 77 to 126 Mg ha-1. The results suggest that tree species differ in C sequestration rates within the forest floor and mineral soil, respectively, but there is little evidence of major differences in the combined forest floor and mineral soil after five decades.

In vitro evaluation of the anti-proliferative activities of the wood essential oils of three Cedrus species against K562 human chronic myelogenous leukaemia cells

There are four kinds of Cedar: Cedrus libani naturally occurring in Lebanon, Syria and Turkey, Cedrus atlantica in Morocco and Algeria, Cedrus brevefolia in Cyprus Island and Cedrus deodara which is distributed in Himalayan Mountains. Wood essential oils obtained from C. libani, C. atlantica and C. deodara were tested for the inhibition of K562 cell proliferation and for the induction of erythroid differentiation. The wood essential oils of C. libani, C. atlantica and C. deodara inhibited the proliferation of the K562 cell line exhibiting IC50 values 23.38 ± 1.7, 59.37 ± 2.6 and 37.09 ± 1.4 µg mL−1, respectively. Meanwhile, C. libani wood oils induced a percentage of erythroid differentiation of 15 ± 2% at concentration 5 µg mL−1. Cedrus deodara wood oil indicated a percentage of erythroid differentiation of 20 ± 2% at concentration 25 µg mL−1 and C. atlantica wood oils showed a percentage of erythroid differentiation of 12 ± 1.8% at concentration 10 µg mL−1.

Pathogenicity testing of four Bursaphelenchus species on conifer seedlings under greenhouse conditions

SummaryThe pinewood nematode, Bursaphelenchus xylophilus (Steiner and Buhrer, J. Agric Res. 48, 1934, 949), Nickle (J. Nematol. 2, 1970, 375), is the causative agent of the pine wilt disease and causes serious damage to pine forests around the world. During a survey for the pinewood nematode, four other Bursaphelenchus species (Bursaphelenchus mucronatus, B. sexdentati, B. anamurius and B. vallesianus) were isolated from wilted pine trees in Turkey. To understand the effects of these Bursaphelenchus species on wilting of pine trees, a study was conducted under greenhouse conditions. Two‐year‐old seedlings of three pine species (Pinus nigra, P. brutia and P. pinea) and one cedar species (Cedrus libani) were used. Fifteen seedlings of each species were inoculated with nematodes and 10 seedlings of each species served as controls. The inoculum densities used for each seedling contained approximately 1000 (±100) nematodes of all life stages in 0.25 ml of distilled water. The first wilting symptoms were observed in the fifth week in all pine species but not in the cedar seedlings. All seeding mortality occurred between the 5th and 13th weeks of the study; no mortality was observed outside of this period. The most pathogenic nematode species was B. mucronatus, closely followed by the other species. The most susceptible seedling species was P. nigra, and C. libani was the most resistant species.

Compatible volume and taper models for economically important tree species of Turkey

The accurate estimation of stem taper and volume are crucial for the efficient management of the forest resources. Compatible segmented polynomial taper and volume equations were developed for Brutian pine (Pinus brutia Ten.), Lebanon cedar (Cedrus libani A. Rich.), Cilicica fir (Abies cilicica Carr.), Scots pine (Pinus sylvestris L.), and Black pine (Pinus nigra Arnold.). In this study, the Clark et al. (USDA For Serv Res Pap SE-282, 1991) segmented taper model was selected as this model is one of the most tested segmented models and has frequently been well ranked for its excellent performance. The data for each species were divided into two sets: the majority (about 75%) was used to estimate model parameters, and the remaining data (about 25%) were reserved to validate the models. The performance of the models was compared and evaluated by average bias, standard error of the estimate (SEE), and a fit index (FI). The proposed model generally performed better than the other equations for the whole tree as well as for sections within the tree, based on the ten relative height classes examined. In addition, tree bole volume estimates were compared to other established tree bole volume estimation techniques. Based on our results, the taper equation of Clark et al. (1991) is recommended for estimating diameter at a specific height, height to a specific diameter, merchantable volume, and total volume for the species considered.

Wound repair and anti-inflammatory potential of essential oils from cones of Pinaceae: Preclinical experimental research in animal models

Ethnopharmacological relevanceEthnobotanical surveys revealed that Abies bornmulleriana, Abies cilicica, Abies nordmanniana and Cedrus libani have been used to promote wound healing in Turkish folk medicine. Four different fir species (Abies cilicica subsp. cilicica, Abies nordmanniana subsp. bornmulleriana, Abies nordmanniana subsp. equi-trojani, and Abies nordmanniana subsp. nordmanniana), Cedrus libani and Picea orientalis were assessed for their in vivo wound healing and anti-inflammatory activities. Materials and methodsThe essential oils from six different coniferous cones were used. In vivo wound healing activity of the plants was evaluated by linear incision and circular excision experimental wound models subsequently histopathological analysis. The healing potential was comparatively assessed with a reference ointment Madecassol®, which contains 1% extract of Centella asiatica. Additionally acetic acid-induced capillary permeability test was used for the oils’ anti-inflammatory activity. ResultsThe essential oils from Cedrus libani and Abies cilicica subsp. cilicica demonstrated the highest activities on the both wound models. Moreover, the oil from Abies nordmanniana subsp. bornmulleriana was found generally highly effective. On the other hand, the rest of the species did not show any remarkable wound healing effect. Results of the present study support the continued and expanded utilization of these plant species employed in Turkish folk medicine. ConclusionThe experimental study revealed that Cedrus libani and Abies cilicica subsp. cilicica display remarkable wound healing and anti-inflammatory activities.

Growth Indicators of Lebanon Cedar (Cedrus libani A. Rich.) and Brutia Pine (Pinus brutia Ten.) in the Cool Supra-Mediterranean Bioclimatic Zone of the Syrian Coastal Mountains

Lebanon Cedar (Cedrus libani A. Rich.) and Brutia pine (Pinus brutia Ten.) growth performance in the Cool Supra-Mediterranean bioclimatic zone of the Syrian Coastal Mountains at Almawla Hassan afforestation site was evaluated. The Pluviothermal quotient of Emberger and the aridity index for the site is 199 and 53.1 consecutively, whereas, summer drought spans for 120 days. The site is dominated by oak Maqui with 80 species distributed equivocally on site aspects. Lebanon Cedar was superior to Brutia pine in all growth indicators. It achieved mean height of 17.97m compared to 14.07m in Brutia pine with significant effects of exposures on the later. Furthermore, it realized a diameter of 27.37cm compared to 23.95cm in Brutia pine with significant effects of exposures on the later species. Basal area (BA) median tree of Lebanon Cedar was 0.058m2, equivalent to 64.78m2/ha. compared with 0.045m2 Brutia pine median tree BA, equivalent to 62.18m2/ha. The growing stock volume (GSV) of Lebanon Cedar median tree was 0.494 m3, and total GSV for its stand was 549.45 m3/ha. whereas, average annual growth reached 13.73 m3/ha/yr. On the other side, GSV of Brutia pine median tree was 0.335 m3, and GSV for its stand was 461.90m3/ha. In the meantime, the species average growth was 11.84 m3 /ha /yr. Tree form factor was greater in Brutia pine. Width of average annual growth rings of the Lebanon Cedar was 4.34 mm/yr. of which 82% of growth was formed in fall compared with 2.42 mm of Brutia pine of which fall growth formed 76%. It is suggested that Lebanon cedar be afforested to similar mountain aspects within this bioclimatic regime along the coastal range mountains.

Growth stages of bare rooted seedlings of Taurus Cedar and Anatolian Black Pine in Eskişehir forest nursery conditions.

Bu calismada, Eskisehir Orman fidanligi kosullarinda yetistirilen farkli orijinlere ait 1+0 ve 2+0 yasli ciplak koklu fidanlarda rutin yetistirme islemleri sonucu; “Kuru madde degisim” yontemiyle “fidan gelisim donemleri” belirlenmistir. Fidanlar, ozel herhangi bir isleme tabi tutulmadan normal yetisme/yetistirme kosullari altinda; ilk gelisme, hizli gelisme, duraklama, odunlasma ve gercek durgunluk donemlerinin yilin hangi donemiyle ortustugu incelenmistir. Fidanlik kosullarina ve ture ozgu gelisim evrelerinin tespitiyle; uygun gubreleme ve sulama rejimleri, kok kesimi, seyreltme, ot alma zamani ve sokum gibi kulturel islemler icin en uygun zamanin belirlenmesi amaclanmistir. Calisma sonucuna gore; 2+0 yasli Toros Sediri fidanlari icin fidan gelisim donemleri; Mart basi - Nisan ortasi durgimluktan cikis donemi, Mayis ayi basi — Temmuz ayi basi gelisme ve hizli gelisme donemi, Temmuz ayi sonu - Agustos ayi ortasi yavaslama donemi, Eylul ayi ortasindan itibaren odunlasma donemine girdigi tespit edilmistir. 2+0 yasli, Anadolu karacami fidanlari icin fidan gelisim donemleri; Mart basi Nisan ortasi durgunluktan cikis donemi, Mayis basi - Temmuz sonu gelisme ve hizli gelisme donemi, Agustos ayinin ortasindan itibaren ve Kasim ayi basina kadar yavaslama ve odunlasma donemini gecirmislerdir. 1+0 yasli Anadolu karacami fidanlari ise; Mayis ayi ortasi - Haziran ayi ortasi fidecik donemi, Temmuz ayi basi — Agustos ayi ortasi gelisme ve hizli gelisme donemi, Eylul ayi ortasi ve Ekim ayi sonu yavaslama ve odunlasma donemi olarak fidan gelisim donemleri belirlenmistir

English

In this study, the reactivity of wood components with acetic anhydride or vinyl acetate was studied. It was found that the reactivity of wood components was virgin wood flour > holocellulose >> a-cellulose. Acetylation of Turkish pine or cedar wood flour with acetic anhydride was significantly improved in the presence of potassium carbonate at 100°C. Maximum of about 20 and 18% weight percentage gain (WPG) values were obtained with Turkish pine ( Pinus brutia ) and cedar ( Cedrus libani ) wood flour after 3 h reaction at 100°C, respectively. The two modification methods and the effect of wood components on vinyl acetate (VA) or acetic anhydride (AA) modification, were characterised by infrared analysis in detail. As an apparent advantage of this new method, acetaldehyde was formed as by-product which is non-acidic was removed easily after the reaction due to low the boiling point of acetaldehyde [b.p. (760 mm Hg) = 21°C]. Key words : Acetic anhydride, vinyl acetate, holocellulose, α-cellulose, FTIR, chemical modification

First Report of Brown Felt Blight Caused by Herpotrichia juniperi on Cedrus libani in Turkey.

Lebanon cedar (Cedrus libani A. Rich) is an ecologically, economically, and historically important conifer species that currently mainly occurs in the Taurus Mountains in southern Turkey. In former times, extensive forests of this species were also found in Syria and Lebanon. However, because of intensive cutting, burning, and goat grazing, only small populations are left in these countries. Currently, the range of Lebanon cedar covers approximately 600,000 ha in Turkey, including extremely degraded stands and bare karstic land that was previously covered by this species (1). Therefore, efforts to protect existing forests and promote natural regeneration of this endangered tree species were undertaken in recent years. In addition, reforestations were carried out on bare karstic lands to expand the population of Lebanon cedar in Turkey. During disease surveys, carried out in October 2009 in the Mt. Dedegül Region of the western Taurus Mountains (37°36'54″N, 31°20'00″E), a dieback of lower branches and young plants of C. libani was observed at 1,700 to 1,885 m above sea level. The disease often occurred in scattered patches and was most evident near the timberline. Needles, shoots, and twigs of affected trees or entire small trees were covered or completely enmeshed in silky, shining, blackish brown mycelial felts. Symptoms resembled those of brown felt blight, also known as black snow mold, caused by Herpotrichia juniperi and Neopeckia coulteri on various other conifer species (2). For fungal isolation and identification, 18 twig samples from 14 different C. libani trees were collected. Two colonized needles from each twig were transferred to water agar (16 g liter-1 of agar and 0.1 g liter-1 of streptomycin) and incubated at 4°C for at least 8 days in the dark. Single hyphal-tip cultures were then established from only one of the developing colonies per twig and transferred to 1.5-ml microcentrifuge tubes containing 500 μl of potato dextrose broth. DNA extraction, directly from the mycelium, was performed after 20 days (3). DNA was amplified using primer pair ITS1 and ITS4 (4) and sequenced. Sequences of two representative fungal isolates from C. libani were deposited in GenBank (HM853976 and HM853977). Comparison of the 18 internal transcribed spacer sequences obtained from C. libani showed 99 to 100% nucleotide identity with those of reference strains of H. juniperi (2) from GenBank and variation among the 18 sequences was <1%, which is within the limits reported in a previous study (2). To our knowledge, this is the first report of C. libani as a new host of H. juniperi. Thus, brown felt blight is considered to have a significant impact on regeneration of C. libani as well as on the survival and growth of seedlings and young trees in the study area.

Modeling stem profile of Lebanon cedar, Brutian pine, and Cilicica fir in Southern Turkey using nonlinear mixed-effects models

The Max and Burkhart segmented taper model was fitted using nonlinear mixed-effects modeling techniques to account for within- and between-individual stem profile variation for Lebanon cedar (Cedrus libani A. Rich.), brutian pine (Pinus brutia Ten.), and cilicica fir (Abies cilicica Carr.) in Turkey. About 75% of the trees were randomly selected for model development, with the remainder used for model validation. Diameter measurements from various heights were evaluated for tree-specific calibrations by predicting random-effects parameters using an approximate Bayesian estimator. The procedure was tested with a validation dataset. Predictive accuracy of the model was improved by including random-effects parameters for a new tree based on upper stem diameter measurements. Prediction in stem diameter was less biased and more precise across the all sections of bole when compared to predictions based only on fixed-effects parameters. In the future, the proposed mixed models can be applied to region wide three species stands by fitting the model to a larger data set that more closely represents regional variation.

Modeling above‐ground litterfall in eastern Mediterranean conifer forests using fractional tree cover, and remotely sensed and ground data

AbstractQuestion: How can we model above‐ground litterfall in Mediterranean conifer forests using remotely sensed and ground data, and geographic information systems (GIS)?Location: Eastern Mediterranean conifer forest of Turkey.Methods: Above‐ground litterfall from Mediterranean forest stands of Pinus nigra, Cedrus libani, Pinus brutia and Juniperus excelsa and mixed Abies cilicica, C. libani and P. nigra was modeled as a function of fractional tree cover using a regression tree algorithm, based on IKONOS and Landsat TM/ETM+data. Landsat TM/ETM+images for the study area were used to map actual stand patterns, based on a land‐cover map of species stands using a supervised classification.Results: Total amount of annual above‐ground litterfall for the entire study area (12 260 km2) was estimated at 417.2 Mg ha−1 for P. brutia, 291.1 Mg ha−1 for the mixed stand, 115.5 Mg ha−1 for P. nigra, 54.6 Mg ha−1 for J. excelsa and 45.9 Mg ha−1 for C. libani. The maps generated indicate the distribution of the seasonal amount of total above‐ground litterfall for different species and the distribution of species stands in the study area. There was an increase in the amount of above‐ground litterfall for P. brutia stand in summer, for J. excelsa in autumn and for C. libani, P. nigra and the mixed stand of A. cilicica, P. nigra and C. libani in winter.Conclusion: Application of this model helps to improve the accuracy of estimated litterfall input to soil organic carbon pools in the Mediterranean conifer forests.

Yields and Constituents of Essential Oil from Cones of Pinaceae spp. Natively Grown in Turkey

In this study, the yields and composition of essential oils obtained from the cones of Pinaceae family species natively grown in Turkey were investigated. Essential oils were obtained by hydrodistillation. Oil yields were 0.13-0.48 mL/100 g in pine cones, 0.42-0.59 mL/100g in fir, 0.36 mL/100g in spruce and 0.37 mL/100g in cedar. While α-pinene (47.1-14.8%) was the main constituent of P. slyvestris, P. nigra and P. halepensis, limonene (62.8%) in P. pinea and β-pinene (39.6%) in P. brutia were found in higher amounts. Like in P. pinea, limonene was the main compound in Cedrus libani (22.7%). In fir species the major compounds were α-pinene (70.6-53.0%) and β-pinene (10.9-8.2%). Contrary to other species β-pinene (32.7%) was found as a major compound in Picea orientalis.

Cedrus libani (A. Rich) distribution in Lebanon: Past, present and future

Long-term vegetation studies are needed to better predict the impact of future climate change on vegetation structure and distribution. According to the IPCC scenario, the Mediterranean region is expected to undergo significant climatic variability over the course of this century. Cedrus libani (A. Rich), in particular, is currently distributed in limited areas in the Eastern Mediterranean region, which are expected to be affected by such climate change. In order to predict the impact of future global warming, we have used fossil pollen data and model simulations. Palaeobotanical data show that C. libani has been affected by both climate change and human activities. Populations of C. libani survived in refugial zones when climatic conditions were less favourable and its range extended during periods of more suitable climate conditions. Simulations of its future geographical distribution for the year 2100 using a dynamic vegetation model show that only three areas from Mount Lebanon may allow its survival. These results extrapolated for cedar forests for the entire Eastern Mediterranean region show that forests in Syria are also threatened by future global warming. In southern Turkey, cedar forests seem to be less threatened. These results are expected to help in the long-term conservation of cedar forests in the Near East.