Jiří Remeš

Effect of Tree Layer and Microsite on the Variability of Natural Regeneration in Autochthonous Beech Forests

ABSTRACT The present study describes natural regeneration on five permanent research plots (PRP) in juvenile growth and development phases (regrowth and advanced growth) in autochthonous beech forests in Broumovské stěny National Nature Reserve located in the Protected Landscape area in the northeast part of Czech Republic. The stands of herb-rich beech forests were studied in the optimum to break-up stage. Natural regeneration was not evenly spaced but rather was clustered. Mean regeneration density ranged from 1,472 to 44,888 recruits per ha. European beech (Fagus sylvatica L.) made up 78.5–98.0% of all regeneration. Sycamore maple (Acer pseudoplatanus L.) was also relatively abundant. Regeneration dominance and abundance responded to the mature stand canopy, soil skeleton, microrelief, ground vegetation cover, and surface characteristics. The results suggest a relationship between recruit height and microrelief in 4 out of 5 PRPs. We found statistically significant differences in height of natural regeneration (F(2,18843) = 191.8, P <0.001) on mounds (74.0 cm), on slopes (119.5 cm) and on pits (121.0 cm) due to high soil skeleton content on mounds with numerous rock outputs, minimum amount of fine earth and lower water retention, both necessary for recruit growth. In addition to the character of microrelief, the growth of natural regeneration was negatively influenced by mature stand density and canopy indicators.

Diameter increment of beech in relation to social position of trees, climate characteristics and thinning intensity

We present the results of research on diameter increment in beech stands in the area of Hostýnské and Vsetínské vrchy. The data were collected on three series of permanent research plots (PRP) in middle-aged stands in the property of BFP Forests and Estates of Tomas Baťa, Ltd. established for the evaluation of the effect of different thinning regimes. Each series consists of one control plot and two plots with different treatment intensity. The objective of this paper was to assess the increment response of beech individuals in the first year after a thinning intervention and to evaluate the increment of sample trees in relation to the social position of tree in the stand and the climate trends in the last 30 years. The diameter increment was evaluated on harvested sample trees, after the thinning treatment the growth reaction of standing sample trees of the main stand was evaluated based on their dendrometric characteristics. To calculate the radial growth of beech, the annual ring increment series were cross-dated individually (to eliminate errors caused by missing annual rings) using statistical tests in the PAST4 application software (Knibbe 2007) and then subjected to visual inspection according to Yamaguchi (1991). If a missing annual ring was found, a ring 0.01 mm wide was inserted in its place. The individual curves from PRPs were then detrended and an average annual ring series was created in the ARSTAN software. First a negative exponential spline was used, and then the 30-year spline was applied (Grissino-Mayer et al. 1992). The response of tree radial growth to climatic factors was evaluated using the DendroClim software. The method of single pointer years analysis was used to estimate the influence of extreme climatic events on diameter growth. One year after thinning, the harvest intensity had no significant effect on the radial growth of dominant trees (F(4, 293) = 1.0, P > 0.05), but oppositely, differences in the average diameter increment of co-dominant trees on PRPs were statistically significant (F(4, 362) = 2.6, P < 0.05). The diameter increment of dominant trees in 1978–2013 showed positive correlations with the March temperatures of the current year (r = 0.27) and negative ones with June–September (r = –0.28 to –0.43) and November (r = –0.36) of the last year and April, June and July (r = –0.35 to –0.44) of the current year. Negative correlations of temperature in the growing season of the current year were similar to dominant trees, only the impact was weaker in April to August (r = –0.28 to –0.32). According to the results of the PCA analysis, annual ring width was negatively correlated with temperatures in the vegetation season of the last year and current year, July, April and June temperature of the current year, and with precipitation in January–March of the current year.

Struktura a modelový vývoj lesních porostů v NPR Trčkov – CHKO Orlické Hory, Česká republika

Abstract The paper deals with the research of structure and dynamic development of stands in National Nature Reservation Trčkov, located in Protected Landscape Area Orlické Mts. (Czech Republic). The research was carried out in spruce-beech stand with admixed fir and sycamore maple. Two permanent research plots (PRP 1 and PRP 2), for each with area of 0.25 hectare were chosen as an object of our research. FieldMap technology was used for field measurement. Compared PRP were characterized by the same typological, soil, phytocenology and stand parameters, but different method of protection against game damage. Results showed that deer is considered to be limiting factor for successful development of natural regeneration of autochthonous tree species. The tree species proportion of natural regeneration occurred in PRP 1 with fencing was sufficient, contrary to PRP 2 (outside fencing) owing to site and stand conditions. The results of biometric measurements and predicted simulation by Sibyla growth simulator showed multi-layer stand structure and productive spruce-beech stands with interspersed fir and sycamore maple. We also found depleted phase of regeneration according to frequency and tree species proportion, as well as beginning of grow up stadium, especially related to fir and sycamore proportion and/or beech and spruce. It is concluded that growth visualization and simulation confirmed the hypothesis about long-term effect of game to species, spatial and age structure and development of concerned autochthonous population.

Magnetic mapping of distribution of wood ash used for fertilization of forest soil

The effect of wood-ash fertilization on forest soils has been assessed mainly through geochemical methods (e.g., content of soil organic matter or nutrients). However, a simple and fast method of determining the distribution of the ash and the extent of affected soil is missing. In this study we present the use of magnetic susceptibility, which is controlled by Fe-oxides, in comparing the fertilized soil in the forest plantation of pine and oak with intact forest soil. Spatial and vertical distribution of magnetic susceptibility was measured in an oak and pine plantation next to stems of young plants, where wood ash was applied as fertilizer. Pattern of the susceptibility distribution was compared with that in non-fertilized part of the plantation as well as with a spot of intact natural forest soil nearby. Our results show that the wood-ash samples contain significant amount of ferrimagnetic magnetite with susceptibility higher than that of typical forest soil. Clear differences were observed between magnetic susceptibility of furrows and ridges. Moreover, the dispersed ash remains practically on the surface, does not penetrate to deeper layers. Finally, our data suggest significant differences in surface values between the pine and oak plants. Based on this study we may conclude that magnetic susceptibility may represent a simple and approximate method of assessing the extent of soil affected by wood-ash.