Improving restoration success through research-driven initiatives: case studies targeting Pinus pinea reforestation stock development in Lebanon

Lebanon is located in one of the most ecologically diverse semi-arid regions of the world, characterized by endemism and richness of higher plants, which persist despite centuries of intensive agro-sylvo-pastoral use and more recent urbanization. Extensive deforestation, fires, and potential desertification have advanced concerns over the sustainability of naturally forested ecosystems in Lebanon, with only ca. 13 % forest cover remaining. Despite high numbers of seedlings planted in recent decades, reforestation success in Lebanon has been historically low. Increased success can be achieved through the effective production of high-quality native plant seedlings, capable of survival in increasingly arid climatic and harsh edaphic conditions. Through two trials focused on Pinus pinea as a model species, we aim to use a research-based approach to identify techniques required to produce high-quality seedlings to improve post-transplant performance in Lebanon. The first trial examines the suitability of using controlled release fertilizer for seedling production and evaluates the effect of fertilizer application rates on seedling morphological and tissue nutrient parameters. The second study examines the role of water availability during the three key periods of seedling development in the nursery to identify the optimal irrigation regime needed to achieve functional attributes associated with seedling drought and cold hardiness. Our findings serve as the first data-driven recommendations for improved seedling production in Lebanon and the greater region as well as demonstrate how locally integrated planning can result in effective capacity building.