Environmental and management factors determining regeneration responses in european temperate forests
- Autores: Iris Pilar Monfort Bague
- Directores de la Tesis: Cristina Vega García (dir. tes.), Pere Casals Tortras (dir. tes.), Lluis Coll Mir (dir. tes.)
- Lectura: En la Universitat de Lleida ( España ) en 2024
- Idioma: español
- Tribunal Calificador de la Tesis: Paloma Ibarra Benlloch (presid.), Luis Serrano Endolz (secret.), Begoña Abellanas Oar (voc.)
- Programa de doctorado: Programa de Doctorado en Gestión Forestal y del Medio Natural por la Universidad de Lleida
- Materias:
- Enlaces
- Tesis en acceso abierto en: TDX
- Resumen
The objective of this doctoral thesis is to understand the factors related to post-disturbance regeneration. The thesis will examine the establishment and growth of individuals in mixed spruce forests in Central Europe and sub-Mediterranean forests following natural or human-induced disturbances. The results of natural regeneration in a mixed spruce forest after a wind disturbance revealed that salvage logging had a positive impact on growth and survival, but for some species, it had a slightly negative effect on browsing and recruitment. Pioneer species, such as birch (Betula sp.), were the first to colonize the managed areas due to the increased light availability and the destruction of advanced regeneration of spruce seedlings. In sub-Mediterranean forests, where resprouting is the primary natural regeneration strategy, it was observed that marcescent species resprouted more vigorously than evergreen and deciduous for the same aboveground biomass after a complete stool cleaning. This suggests that the ability and vigour of resprouting varies among and within species. When stem selection was applied to box-tree individuals growing in the understory, the number of resprouts and their lengths were lower in stools where stem selection was done, compared to stools where complete cleaning was applied. This indicates that stem selection can reduce the resprouting vigour. Our results also suggested that resprouting vigour was regulated by the allocation of stored resources and the capacity to acquire new ones through photosynthesis of the new ones.
In an experimental plantation established in the Catalan pre-Pyrenees, we observed a trade-off seven years later: species with higher survival ratio under shade of tree canopy, showed lower growth rates. Leaf habit or provenance did not play a significant role in explaining species survival, which appears to be more closely related to the capacity of species to withstand cold at high altitudes or drought. Despite a positive correlation between light and aboveground biomass in deciduous species, the increase in aerial biomass with increasing light availability was more pronounced at the species level and was likely related to the plasticity of the various traits studied: to increase or maintain their aerial biomass in response to increased light availability, deciduous species exhibited plasticity by increasing the number of leaves while reducing the individual leaf surface area. In contrast, evergreen species limited individual leaf-level plasticity and primarily responded to increased light availability by increasing the number of leaves. Marcescent species exhibited a behaviour between both groups, slightly reducing the specific leaf area and increasing the number of leaves under increasing light availability.
