A dendroecological perspective on tree life history across a gradient of primary temperate forests in Central, East, and Southeast Europe

Jakob Pavlin, M.Sc.

Disertační práce

Abstract:

Objectives of thesis Tree life history strategies are crucial determinants of forest community structure and dynamics. Knowledge of tree life history traits is thus critical for a more comprehensive understanding of forest ecosystem tendencies. Furthermore, quantifying these developmental characteristics and how they relate to dominant drivers may serve as an important basis for projections of future forest states. Using dendroecological and supporting data collected on up to 1000 permanent sampling plots, the main aim of this thesis is to analyze the variability in some of the key life history traits such as longevity and canopy accession of the dominant tree species across primary temperate mountain forests of Central, East, and Southeast Europe. Additionally, the aim is to examine and assess the relationships between tree life history traits and their drivers. The specific objectives of this thesis were: 1) To quantify the life span variability among dominant tree species and analyze the dominant drivers of their life spans. Additionally, to assess the landscape variability of old tree densities. 2) To analyze the variability of canopy accession patterns across dominant tree species and to investigate how these patterns are influenced by disturbance history, climate, and topography. 3) To investigate growth releases in dominant tree species and examine the species‐specific relationships between the growth and duration of growth releases and multiple factors, including disturbance severity, climate conditions during release, topography, tree age and size, as well as temporal trends. Methodology To address the objectives of this thesis, data were collected in the scope of a large‐scale network of permanent sampling plots located in primary temperate mountain forests of the Balkan Mountains, Carpathians, and Dinarides. Plots were set up using a stratified random design covering an elevational gradient from broadleaf‐dominated and mixed forests at lower elevations to conifer‐dominated forests at higher elevations. Data collection encompassed documenting physiographic site information, dendrometric data and collecting tree increment cores. Tree increment cores were processed using standard dendrochronological techniques. Ring widths were measured and cross‐dated and were subsequently used to calculate the life‐history‐related parameters and to reconstruct the plot‐level disturbance histories. The interspecific variability in life‐history‐related parameters was ultimately assessed using generalized linear mixed effect models in combination with post‐hoc tests, while the trait drivers were analyzed using generalized linear mixed effect models.

Keywords

Disturbance, Life span, Canopy accession, Radial growth, Irradiance, Shade tolerance, Growth release, Suppression, Abies alba, Acer pseudoplatanus, Fagus sylvatica, Picea abies

Jazyk práce: angličtina

Datum vytvoření / odevzdání či podání práce: 1. 10. 2024

Obhajoba závěrečné práce

• Vedoucí: Thomas Andrew Nagel

Česká zemědělská univerzita v Praze

Fakulta lesnická a dřevařská

Doktorský studijní program / obor:
Forestry Engineering / Forest Biology