RESUME

Gene Pool Management of Forest Species from the Aspect of Forest Protection

Radomír Mrkva

Tree species gene pool is understood as a set of genetic features acquired by a long previous natural selection, which allow, like a kind of “historical experience”, the trees grow and propagate at the site of their occurrence. The author stresses merely decisive importance of permanently ongoing natural selection updating the ecological valence of plants. Protection of gene pool, i.e. protection of genetic diversity of varied genetic properties, out of which the ability to survive is the most important generally and the quality of stem is important for forestry production, has to be understood as a dynamic process.

It is performed both by the transfer of genetic properties and namely by selection of the youngest stages in the phase of natural regeneration. The selection continues also further on during the stand development and should be performed in a way adequate to the forest formation. Therefore it is necessary to support the share of natural forest regeneration in a long period of stand lifetime from the beginning of its maturity. Only then the toughest selection may go on and it is obvious such ideas can be fulfilled by the means of so called nature-close management. For the formation of Mid-European mixed forests, the selection system will be the most frequently used. With currently worsening health of forests caused apart from other anthropogenic impacts also by constricted gene pool resulting from long application of artificial regeneration it is necessary to strive for conservation of tree species gene pool, which will be able to resist possible impacts of “climatic change”.

Forest Vitality Evaluation by Electrodiagnostic Method on ICP Forests Monitoring Sites

Vladimír Rajda, Petr Fabiánek (pp. 308-309)

The evaluation of forest tree’s health has recently been enhanced by a new electrodiagnostic method using a direct measurement of electric currents running permanently between trees and their nutrient soil environment during the whole lifetime. This process is a natural and intrinsic component of energetic processes in metabolism. Regular connection of these electric currents and metabolic activity and health of trees sustains homogeneously in all plant species independently from the site conditions, altitude, geographical longitude and latitude. This all justifies this parameter as a reliably measurable degree of tree vitality.

GEO-FYTO electric currents always depend on the intensity and quality of internal physiological processes of plants. Unfavourable changes in these processes naturally reflect in the health of plants. External, visually observable changes of tree crown health are therefore a consequence of physiological changes. GEO-FYTO electric currents may be applied as a comprehensive objectively measurable indicator of changes in tree’s health, which reflects sensitively changes in metabolic activity and provides precise information on tree vitality from the very initial developmental stadium of a change of health before the first visually noticeable symptoms appear.

In order to verify the electrodiagnostic measurability of tree vitality on the ICP Forests monitoring sites in the CR 5 monitoring sites were selected so that the species composition and frequency can provide satisfying conditions for reliable verification of vitality measurability. The authors conclude the comparison of results of the two different evaluation methods (ICP Forests and the electrodiagnistic method) of tree health conditions proves a good agreement of observed values and confirms again close relationships between visible external health characteristics of tree crowns and the intensity of internal physiological processes, defined by the measurable electrodiagnostic symptom of vitality. In all cases the GEO-FYTO values of electric currents corresponded with external health symptoms (defoliation, colour changes of assimilating apparatus) and internal ones (tint and water saturation of phloem and cambial layers) of the examined trees.