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  • Author: Milan Barna x
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Abstract

At beginning of the 1980‘s, the National Science Foundation (USA) came up with the initiation of the program for Long-Term Ecological Research (LTER), which is a program based on long-term comprehensive study of the structure and processes of ecosystems. The Ecological Experimental Station (EES) in the Kremnické vrchy Mountains (Western Carpathians, Slovakia, 1986) was founded for similar purposes. The aim of the research at EES was to evaluate the productivity, carrying capacity and functioning of the beech ecosystem. In February 1989, five plots were established. Four plots were subjected to a regeneration cutting of different intensities (clear-cut, strip shelterwood cut: light, medium and heavy). The fifth plot was left without any management treatments as a control. The second cutting was performed in 2004 followed by the final cutting five years later. Currently, the research is carried out on the EES control plot in the stand comprising 115–120 years old beech trees. In the other stands the research is focused on the development of naturally regenerated beech ecosystems established after different cutting interventions. The future of the EES is in addressing some global issues, particularly the impact of climate change on primary production, as well as on its other consequences for the functioning of the affected ecosystems.

Abstract

We investigated the current health condition (defoliation), state of natural regeneration, and mycoflora and phytopathogen-caused attacks in Scots pine forests (Pinus sylvestris L.) planted in the 1960s in areas affected by wind disturbances in the West Rhodope Mountains in Bulgaria. Some damage types (resin outflow and anthropogenic damage) were present to a low extent in the research plots (S – Selishte and PK – Pobit Kamak). Some were missing completely (damage by deer and other animals, the presence of lignicolous fungi and abiotic damage). The most important results of this study were the following: i) the occurrence of the bark beetle pest Tomicus minor Hartig (Coleoptera, Scolytinae) was recorded on average in 4.6 (S) and 2.3 (PK) of fallen shoots under the tree crown within 1 m diameter around the stem; ii) significant damage to tree crowns due to the loss of assimilation organs in Scots pine trees (28% – S and 39% – PK, respectively) was several times higher than that recorded in Norway spruce (Picea abies L.) (10%); iii) tree species composition resulting from natural regeneration showed 95–100% proportion of Norway spruce despite the predominance of Scots pine in the maternal stand. These observations might provide evidence of unsuitable environmental conditions in the studied localities for pine forests on the southern range of the natural P. sylvestris occurrence. Forest management in similar ecological and climatic conditions should aim at significant diversification of the forest stand structure by utilizing tree species suitable for the given ecosystems.

Abstract

Extracting cores from a tree using an increment borer has been standard practice in dendrochronological studies for a long time. Although empirical rules exist regarding how many samples to take and which methodology to apply, comparatively few studies provide quantification of the similarity of relative tree-ring-widths (TRW) around the stem circumference. The aim of this study was therefore to precisely measure the similarity of standardised TRWs around the stem circumference and to provide objective suggestions for optimal core sampling of Norway spruce (Picea abies Karst. [L.]) and European beech (Fagus sylvatica L.) growing in Central European temperate forests.

A large sample of cross-sectional discs was used from Norway spruce and European beech trees growing on various slopes, at different altitudes and biogeographic regions across the Czech Republic and Slovakia. The similarity of TRWs measured in different coring directions was analysed by testing the relativized TRW around the trunk (rTRW). Comparison of rTRWs revealed no significant differences between coring directions, indicating that the relative increment was the same around the radius. The results also showed the high similarity between the rTRWs to be independent of both slope inclination and altitude. Moreover, the reconstruction of proportional tree diameters and basal areas backward in time from one core sample and one measurement of tree diameter (basal area) at the time of sample extraction is possible with reasonable precision.