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To better guide Cedruslibani provenances movement to northerly and higher-altitude sites for afforestation, the limits of hardiness to cold should be better known. In this study, we quantified the cold hardiness of seven C.libani provenances sampled from a provenance trial in Ankara, Türkiye, a site located outside the natural range of distribution of the species. Visual damage observation and chlorophyll fluorometry screening methods were used to assess variation in cold hardiness (LT50, the temperature estimated at which 50% of the needle tissue is damaged) among populations. Overall, C.libani can tolerate winter temperatures down to − 21.5 °C. Even though there were significant differences in cold hardiness among populations, the maximum difference was only 1.9 °C between the most and the least cold-resistant provenances. Cold tolerance was generally greater for provenances that experienced colder temperatures in March and lower levels of total precipitation in their native ranges. We also conclude that the fluorometry method provides a more efficient and stable comparison of cold hardiness than visual observation for C.libani. The results of this study may be useful for assisted migration and breeding programs, as well as for developing guidelines for genetic materials transfer, to increase productivity or adaptability of C.libani. [ABSTRACT FROM AUTHOR]

This study investigated the potential acaricidal and repellent effects of tar obtained from the Lebanon cedar (Cedrus libani A. Rich.) against the brown dog tick species Rhipicephalus sanguineus sensu lato Latreille (Acari: Ixodidae). The goal was to find an alternative, safe, and effective way to eliminate ticks. Tar is traditionally extracted from cedar trees in the Antalya region of Türkiye. The composition of the tar is primarily characterized by a diverse mixture of terpenes, with β-himachalene (29.16%), α-atlantone (28.7%), ar-turmerone (8.82%), longifolene-(V4) (6.66%), α-himachalene (5.28%), and β-turmerone (5.12%) emerging as the predominant constituents. The toxic effects of tar on tick larvae were studied through larval immersion tests (LIT), and its repellent activity was evaluated using a new larval repellent activity test (LRAT). The results revealed significant acaricidal effects, with mortality rates of 77.7% and 82.2% for the Konyaalti and Kepez strains of the brown dog tick, respectively, in response to a 1% concentration of tar. LC50 and LC90 values were determined as 0.47% and 1.52% for the Kepez strain and 0.58% and 1.63% for the Konyaalti strain, respectively. When comparing the repellent effect of tar to the widely used synthetic repellent DEET, repellency rates of up to 100% were observed. As a result, this study establishes, for the first time, the larvicidal and repellent effects of C. libani tar on ticks. [ABSTRACT FROM AUTHOR]

The remnants of old-growth cedar forests in Lebanon are currently protected since they are taken to represent relic ecosystems sheltering many endemic, rare and endangered species. However, it is not always obvious how "natural" these forest relics are, and how the past use, conservation and management history have affected their current structural properties and species community composition. Even though Integrated Monitoring Programs have been initiated and developed, they are not being implemented effectively. The present research studied the effect of forest stand structure and the impacts of the anthropogenic activities effects on forest composition and floristic richness in four cedar forests in Lebanon. Horizontal and vertical structure was assessed by relying on the measurement of the physical characteristics and status of cedar trees including diversity and similarity indices. Two hundred and seventeen flora species were identified, among which 51 species were found to have biogeographical specificity and peculiar traits. The species composition seems not to be correlated with stand age structure; however, the occurrence of multiple age cedar stands favors floristic richness and variability in species composition as observed in one of the stands where the variation in diversity indices was high. In conclusion; to conserve biodiversity across landscapes, it is necessary to maintain a collection of stands of different vertical structure; an effect produced both by natural and anthropogenic disturbances since they both create a mosaic of different aged succession stands. [ABSTRACT FROM AUTHOR]

Abstract: 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. [ABSTRACT FROM AUTHOR]