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Open access

Ladislav Kulla and Michal Bošeľa

Abstract

The paper proposes and justifies an alternative concept of aggregation of forest site types in higher units for purposes of differentiation of forest management. Analysis of variance was performed for both: the natural occurrence of tree species in reserves, as well as the production potential of tree species measured on the representative plots according to Zlatnik´s altitudinal vegetation zones and edaphictrophic series. Based on the results of this analysis, an aggregation of forest site types was suggested along the elevation gradient of climatop, and along the edaphic-trophic and the edaphic-hydric gradients of edaphotop. By intersection of such created 32 categories of geotope with the basic formation groups of forest habitats by Braun-Blanquet geo-botanical school, 53 reconstructive geo-biotopes were formed. The proposed unit was compared using the F-test, Akaike information criterion (AIC), and the index of classification efficiency (EQ) with current typological units in terms of its ability to describe the variability of the analyzed parameters. Finally, the qualitative association of the compared classification models with the European classification systems was assessed. Based on the results obtained, it can be concluded that the site unit geo-biotop is at least comparable with currently used unit MGFT, with the number of categories lower by 72%.

Open access

Ladislav Kulla and Vladimír Šebeň

Abstract

The paper deals with non-whole-area artificial reforestation as a new rationalization method of forest regeneration based on a combination of planting of desirable tree species and natural regeneration of other tree species from surrounding adult stands. It presents the first preliminary results of the experiment established on the demonstration area Kysuce - locality Husarik. The first results suggest that non-wholearea artificial regeneration can bring significant cost savings in establishing and subsequent treatment of the forest cultures. On the other hand, the question of ensuring adequate regeneration of desirable tree species in required time remains open at this time, and longer monitoring is necessary.

Open access

Rudolf Petráš, Julian Mecko and Ladislav Kulla

Abstract

Tree maturity of the four main tree species that are most frequent in the uneven-aged forests of the Western Carpathians was analysed. The maturity was determined on the base of the economic value production in relation to tree diameter. We derived mean timber values of spruce, fir, pine, and beech trees (€ m−3) depending on their diameters, quality and stem damage, and in the case of beech also depending on tree age. The assortment structure was calculated using the models of tree assortment tables that account for the stated tree parameters. The assortment prices were taken from the price list of logs in assortment and diameter classes of the Forests of the Slovak Republic, state enterprise, for the year 2016. Trees are mature when their mean timber monetary value is at maximum. Results show, that the highest mean value production of the majority of beech trees of average and above-average stem quality is 70 - 80 € m−3 for trees with diameters between 45 and 55 cm. Monetary values of spruce and fir trees with diameters above 60 to 90 cm are 80 - 95 € m−3, while the monetary values of pine trees with the same diameters are approximately 70 - 115 € m−3. The value production of trees is reduced if the stems are of worse quality or damaged, but in the case of beech it also decreases with greater diameter or tree age.

Open access

Ladislav Kulla, Ivan Sačkov and Miroslav Juriš

Abstract

Even if stand inventories based on growth tables have been widely discussed over the last years, this method of forest mensuration is still widely applied due to favourable ratio between costs and achievable precision of stand growing stock estimation. The aim of the study was to verify the potential of airborne laser scanning data (ALS) for direct estimation of mean stand height and mean stand density (stocking) as fundamental inputs for forest mensuration based on yield tables. The material from two reference plots with substantially different stand structure was processed by REFLEX software, and confronted with the results of the precise terrestrial inventory. The number of detected tree tops decreased from 100% in the case of super-dominant trees to 30% and 5% in the case of supressed trees at the homogeneous and heterogeneous plot, respectively. The correlation of ALS heights with terrestrially measured heights was R = 0.88 at the homogenous plot, and R = 0.77 at the heterogeneous plot. The tendency to underestimate dominant and to overestimate suppressed trees was revealed at both plots, but was more pronounced at the heterogeneous one. Nevertheless we justified that the mean ALS height calculated from the heights of the detected trees represented the biometric mean stand height linked to the stem with the mean basal area quite well. The stocking estimated by REFLEX software according to delineated crowns´ area was also closer to the real value of stocking than the one obtained by the routine mensuration procedure. The results indicate promising potential of the ALS data processed by REFLEX software to rationalise forest mensuration based on yield tables in even-aged forest structures.

Open access

Ladislav Kulla, Michal Bošeľa, Vlastimil Murgaš, Joerg Roessiger and Vladimír Šebeň

Abstract

The decision to change forest management system from the traditional even-aged to the selection one based on statistical inventory is often limited by a missing previous inventory. To avoid this issue, we used available forest inventory data from ca 2 000 ha of mixed uneven-aged beech-fir-spruce-pine forest and tree ring data from 831 trees to reconstruct forest status from one decade ago. For this purpose, we have created three sets of species-specific models: 1) diameter-stump models to reconstruct the diameter of missing trees, 2) diameter-increment models based on tree ring data to estimate past diameters, and 3) height-diameter models to estimate past tree heights. This approach has allowed us to completely reconstruct the state of the forest as it was ten years ago and use the results as a substitution for a previously missing inventory.

Open access

Maroš Sedliak, Ivan Sačkov and Ladislav Kulla

Abstract

Remote Sensing provides a variety of data and resources useful in mapping of forest. Currently, one of the common applications in forestry is the identification of individual trees and tree species composition, using the object-based image analysis, resulting from the classification of aerial or satellite imagery. In the paper, there is presented an approach to the identification of group of tree species (deciduous - coniferous trees) in diverse structures of close-to-nature mixed forests of beech, fir and spruce managed by selective cutting. There is applied the object-oriented classification based on multispectral images with and without the combination with airborne laser scanning data in the eCognition Developer 9 software. In accordance to the comparison of classification results, the using of the airborne laser scanning data allowed identifying ground of terrain and the overall accuracy of classification increased from 84.14% to 87.42%. Classification accuracy of class “coniferous” increased from 82.93% to 85.73% and accuracy of class “deciduous” increased from 84.79% to 90.16%.

Open access

Justyna Chodkowska-Miszczuk, Marián Kulla and Ladislav Novotný

Abstract

Energy production by agricultural biogas plants has recently recorded considerable growth in Visegrad countries. The development was enhanced by European Union’s efforts to increase the proportion of energy produced from renewable sources. The paper aims to assess the role of energy policy in the development of agricultural biogas energy production in Visegrad region. Conducted studies have shown that among various forms of support for energy production from renewable energy sources, the price system prevails, including the support by feed in tariffs and bonuses. Feed in tariffs were adopted in Czech Republic, Hungary and Slovakia. Another kind of support system – a quota system – was adopted in Poland, what includes tendering and certificate systems. The results confirm the adoption of legal framework was necessary step to enable agricultural biogas energy production in Visegrad countries, but itself it was not enough to stimulate development of agricultural biogas energy production significantly. Rapid development in each country was recorded only after the certain financial support systems took effect, what made production of agricultural biogas energy economically efficient for investors. The production of energy from agricultural biogas grew the most in the Czech Republic and Slovakia, where the financial support was the highest. Nevertheless, the protracted process of changes in legal framework and transformation of energy policy, certain measures including state-controlled price-making systems, risk regarding with auction system might hamper agricultural biogas energy production further development.

Open access

Ladislav Novotný, Stela Csachová, Marián Kulla, Janetta Nestorová-Dická and Loránt Pregi

Abstract

Small towns, compared to larger cities, are specific group of municipalities with weaker performance in many spheres of socio-economic development. The aim of the paper is to comprehensively evaluate development of twelve small towns in the region of East Slovakia over the centuries up to present. The paper deals with question how their demographic and economic developments have been reciprocally influenced under particular historical circumstances. Using various sources of statistical data and employing traditional historical, mathematical-statistical and cartographical methods, regularities and patterns were identified that enabled us to categorize small towns and evaluate their development trajectories and current roles in the settlement system. In the most cases, they are still valid nodes for their hinterlands even though their past situation has been unfavourable.

Open access

Tomáš Hlásny, Csaba Mátyás, Rupert Seidl, Ladislav Kulla, Katarína Merganičová, Jiří Trombik, Laura Dobor, Zoltán Barcza and Bohdan Konôpka

Abstract

The paper presents information on the projected drought exposure of Central Europe, describes the anticipated dynamics of the regional forests, and identifies measures facilitating the adaptation of forests to climate change-induced drought risk. On the basis of an ensemble of climate change scenarios we expect substantial drying in southern Slovakia and Hungary, while such trends were found to be less pronounced for the Czech Republic and Austria. In response to these climate trajectories, a change in species composition towards a higher share of drought tolerant species as well as the use of drought resistant provenances are identified as paramount actions in forest adaptation in the region. Adaptation to aggravating climate change may need to use artificial regeneration to enrich local gene pools and increase the drought tolerance of stands. Increasing risks from pests, pathogens and other disturbances are expected as a result of more frequent and severe droughts, underlining the need to put a stronger focus on risk management principles rather than on indicators of productivity in silviculture and forest planning. A consolidation of disturbance monitoring systems and a broader use of pest dynamics and hazard rating models are paramount tools to facilitate this adaptation process in forest management. The effectiveness of all the suggested measures needs to be controlled by efficient forest monitoring systems, the consolidation of which seems to be a timely task. Systematic and long-term implementation of the presented measures should increase forest stability and resilience, and further secure the sustainable provision of ecosystem services under climate change.