The diversification of forest stands and the use of saplings and semi-saplings on mid-elevation sites

Ing. Josef Gallo, MSc

Doctoral thesis

Abstract:

The thesis is aimed at the verification of the use of large-sized planting stock on mid-elevation sites as a contribution to the regeneration and transformation of forest stands to reach the stability and diversity of forests. The goal is primarily to test the suitability of new generation saplings and semi-saplings (NGSS) of deciduous tree species on selected experimental plots for this purpose. The work analyses and summarizes the outcomes of several field experiments focused on testing the large-sized planting stock on mid-elevation sites. Mortality, growth and other characteristics of NGSS on selected research sites were evaluated. NGSS is characterized by an advanced, rich and compact root system and an improved ratio of aboveground and underground biomass to standard planting material, as well as generally larger dimensions. The basic hypothesis was that the NGSS show better growth dynamics on (exposed and extreme) habitats. The research was done on the basis of the evaluation of older research experimental plots, but new plots were also established. Additional analyses included the application of brassinosteroids onto advanced planting stock during the post-planting period, analyses of the chlorophyll content of NGSS and standard planting stock, and the determination of aboveground and underground biomass volumes in the tested planting stock types. New generation saplings and semi-saplings showed generally better increments in both height and root collar diameter as well as improved vitality. This was confirmed on various types of habitats. Therefore, this type of planting stock is recommended for reforestation and afforestation in specific and difficult cases, considering its higher costs. Basic economic analysis and evaluation of the economic efficiency of using the NGSS system is a part of the work. With different combinations of the number of planted trees and mowing regimes, the economic endurance of the NGSS system can be achieved thanks to the better attractiveness and vitality of the NGSS.

Keywords

large-sized planting stock, broadleaves, reforestation, economics of afforestation, above-ground and below-ground biomass, forest structure

Language used: English

Date on which the thesis was submitted / produced: 26. 3. 2021

Thesis defence

• Supervisor: doc. Ing. Ivan Kuneš, Ph.D.

Czech University of Life Sciences Prague

Faculty of Forestry and Wood Sciences

Doctoral programme / field:
Forestry Engineering / Silviculture