Potentiel d'utilisation de la diversité fonctionnelle des arbres dans l'aménagement durable des forêts tempérées nordiques et boréales
|Authors:||Laginha Pinto Correia, David|
|Advisor:||Raulier, Frédéric; Bouchard, Mathieu; Larose-Filotas, Élise|
|Abstract:||Forest management objectives have slowly changed over the last few decades. While forest management used to focus mainly on wood production, forests are now expected to be managed for multiple ecosystem services. Traditional forest management strategies are also unsuitable to tackle the threats posed by climate change and by the increased frequency of climate extremes. The development of biodiversity indicators capable of predicting ecosystem response to disturbances has been identified as one of the key research priorities in the improvement of existing sustainable forest management frameworks. However, our understanding of these biodiversity-ecosystem functioning relationships and their response to disturbances needs to be improved if such indicators are to be developed. The objective of this thesis was to analyse the potential of tree functional diversity indicators in improving sustainable forest management of northern temperate and boreal forests. In my first chapter, I studied the impact of stand age, height and cover type on multiple tree biodiversity indicators. My analyses showed that stand age, one of the most widespread indicators of biodiversity, should not be used as the sole indicator of tree diversity in forest management because it inadequately represents a significant part of stand tree diversity. In my second chapter, I analysed the relationship between two indicators of pre-logging functional diversity (functional redundancy and response diversity), and post-logging stand productivity. My results revealed the importance of considering functional diversity in biodiversity-ecosystem functioning studies and showed that response diversity is significantly associated with post-logging productivity in these forests. In the last chapter, I examined the relationship between three functional traits associated with tree resistance and resilience to drought. My results showed that, in our study area, dry leaf mass per unit area and xylem pressure at which 50% of stem xylem conductivity is lost through cavitation significantly influence drought-induced tree mortality, but do not affect stand productivity response to drought. This thesis revealed the importance of the relationships between tree functional diversity, stand productivity and stand response to partial and severe disturbances. Besides improving our scientific understanding of the relationships between functional diversity and ecosystem functioning, these results allowed us to propose several tree-diversity based forest management strategies that should considerably improve stand resilience and resistance to disturbances.|
|Document Type:||Thèse de doctorat|
|Open Access Date:||11 September 2018|
|Collection:||Thèses et mémoires|
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