The environmental impact on woody plants functioning

Rapid and sudden changes in environmental conditions have a significant impact on woody plants, a crucial component of ecosystems where they perform numerous ecosystem services. The complexity of the anatomical structure, combined with the long lifecycle of woody plants, and logistical difficulties in terms of terrain and tissue accessibility, has resulted in significant knowledge gaps regarding the environmental impact on the woody plants functioning. Consecutively, this impacts forest ecosystem management strategies that need to rely on on-field observations and measurements to ensure a positive outcome in various stages of afforestation and reforestation efforts, from species selection to nursery production, outplanting, and sites management. Considering the aforementioned, the goal of the present PhD research project is to fill in some of these gaps. Therefore, several studies using different methodologies were conducted, in order to explore three research axes. The first research axis focused on afforestation success and the characteristics of woody plants grown in the arid and semi-arid regions of Mongolia. By analysing the anatomical characteristics of the secondary structure in the stem and root, the goal of this work was to investigate the wood response to environmental stress (Chapter 1). In the second research axis, the focus was extended toward the potential of plant biology to enhance the establishment and advancement of forest ecosystems. For this purpose, two separate case studies were conducted, i) the patterns of biomass partitioning as a way to further explore the plant development in the Mongolian steppe, and ii) the potential of using anatomical characterization of roots as a tool to understand the impact of containers on seedlings development during nursery cultivation (Chapter 2). In the third research axis, considering the previously understood lack of knowledge regarding woody roots, the focus was directed toward the potential of an interdisciplinary approach when studying woody roots (Chapter 3). Overall, the studies performed during the PhD research project have contributed to a better understanding of the environmental impact on woody plants functioning. The work has highlighted the need for focused research on semi-arid areas since their climatic conditions could soon be a reality for many other areas worldwide. The implemented methodologies have also allowed for analysis of the output from large afforestation activities and recommendations for their improvement. Finally, the work has also underlined the importance of an integrated and interdisciplinary approach, by using techniques commonly reserved for fundamental biology in the service of applicative sciences such as forestry.