Properties of the tree layer vegetation modulated by environmental heterogeneity in the small forest fragments in Český kras

Arnau Bosch Guiu

Master's thesis

Abstract:

Forest fragmentation in Central Europe during the last several decades has caused 40% of the remaining forests to be located within 100 meters of the forest edge. Although responses to forest margins have been extensively studied, a consensus is still lacking. It is increasingly necessary to understand vegetation responses in fragmented ecosystems surrounded by an unfavorable matrix. This study aims to analyze how slope, edge, and soil conditions, as well as the size of forest fragments in Bohemian Karst modulate basal area of trees at different scales: (1) generalized response of individual trees, (2) response at biotope level, (3) response at species level, and (4) generalized response of stand basal area for each plot. Generalized additive models (GAM) to analyze the available data. Significative responses to various environmental properties were found for all the analyses except for stand basal area. Basal area was observed to increase near forest edges, and the influence of edges is suggested to reach further than 200 meters into forest fragments for the tree layer. In general, edges facing south (S) and southwest (SW) exhibited higher basal areas. Fragment size did not exhibit any general pattern, but biotope and species-specific patterns. The slope was negatively related to the basal area, and southeast (SE) facing slopes were associated with bigger trees. Nitrogen was a limiting factor for tree growth in general, while phosphorus was a more determinant factor at biotope level. These results contribute to a better understanding of the role of forest edges, highlighting specific responses for different biotopes and species, and emphasizing the importance of conserving large forest fragments.

Keywords

tree species, soil nutrients, slope, light, edge influence, edge effect, landscape, climate change

Jazyk práce: English

Datum vytvoření / odevzdání či podání práce: 31. 3. 2022

Obhajoba závěrečné práce

• Vedúci: RNDr. Jan Hofmeister, Ph.D.

Czech University of Life Sciences Prague

Faculty of Forestry and Wood Sciences

Master programme:
Nature Conservation