Róbert Sedmák

Possible causes of the recent rapid increase in the radial increment of silver fir in the Western Carpathians

Silver fir is one of the most productive and ecologically valuable native European tree species, however, it has been experiencing decline which has periodically occurred over its natural range. This paper aims to investigate the recent climate-growth relationships of silver fir (Abies alba Mill.) and its temporal change along the course of its life. Long-term tree-ring databases, as well as records on climate, atmospheric SO2, NO3 and acid concentrations from four different regions in the Western Carpathians were used. The results provide clear evidence of significant increase of silver firs radial increment over the entire Western Carpathian area since 1970-1980. The results indicated that the most probable factors behind the rapid recovery of tree radial increment were reductions in emissions of NO3 and SO2, alongside a significant increase in mean June, July and April temperatures.

Sustainable forest management in a mountain region in the Central Western Carpathians, northeastern Slovakia: the role of climate change

European forestry is facing many challenges, including the need to adapt to climate change and an unprecedented increase in forest damage. We investigated these challenges in a Norway spruce-dominated mountain region in Central Europe. We used the model Sibyla to explore forest biomass production to the year 2100 under climate change and under two alternative management systems: the currently applied management (CM), which strives to actively improve the forest’s adaptive capacity, and no management (NM) as a reference. Because biodiversity is thought to have mostly positive effects on the adaptive capacity of forests and on the quality of ecosystem services, we explored how climate change and management affect indicators of biodiversity. We found a differential response across the elevation-climatic gradient, including a drought-induced decrease in biomass production over large areas. With CM, the support of non-spruce species and the projected improvement of their growth increased tree species diversity. The promotion of species with higher survival rates led to a decrease in forest damage relative to both the present conditions and NM. NM preserved the high density of over-matured spruce trees, which caused forest damage to increase. An abundance of dead wood and large standing trees, which can increase biodiversity, increased with NM. Our results suggest that commercial spruce forests, which are not actively adapted to climate change, tend to preserve their monospecific composition at a cost of increased forest damage. The persisting high rates of damage along with the adverse effects of climate change make the prospects of such forests uncertain.

Evaluating similarity of radial increments around tree stem circumference of European beech and Norway spruce from Central Europe

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.

Spatial and non-spatial harvest scheduling versus conventional timber indicator in over-mature forests

Abstract This paper presents two alternative approaches of final cut scheduling for a fifty year strategic planning horizon. One approach is represented by cutting percentage, which is a classical timber indicator commonly used in the Czech and Slovak Republics. The second approach is represented by two optimisation models of integer programming; the first model without spatial aspect and the second model including adjacency constraints. Both optimisation models are derived for the clear cut management system with the scheduling approaches applied on an example of a forest management area with over-mature stands. The main aim of the paper is to compare two suggested optimisation models with the classical scheduling approach and to demonstrate their positive effect on the age class distribution of forests. The further aim is to include green-up constraints in the scheduling, which respect legislative conditions. The results show that even in the case of a single management system, without considering different ecosystem services, the optimisation model that does not consider the spatial aspect gives comparable results to the approach that r includes the adjacency constraints. The primary hypothesis, that the regular age-class distribution and flow harvesting cannot be achieved when considering green-up constraints, was rejected Abstrakt Práce prezentuje dva alternativní přístupy k plánování mýtních těžeb v rámci 50 letého strategického plánovacího horizontu. Jeden přístup je reprezentován klasickým těžebním ukazatelem, těžební procento, který je běžně používaný v České a Slovenské republice. Druhý přístup je reprezentován dvěma optimalizačními celočíselnými modely; první model je bez prostorového aspektu, druhý pak zahrnuje vztahy omezení sousednosti. Oba dva optimalizační modely jsou odvozeny pro holosečný hospodářský způsob. Alternativní přístupy plánování těžeb jsou aplikovány na příkladu lesního hospodářského celku s převahou přestárlých porostů. Hlavní cíl práce je porovnat navržené optimalizační modely s klasickým postupem plánování mýtní těžeb a demonstrovat pozitivní vliv navržených těžeb těmito modely na věkovou strukturu lesa. Dalším cílem je zahrnout do modelu zákonná omezení vzájemného přiřazování holých sečí. Výsledky ukazují, že i v případě jednoduchého hospodářského způsobu bez zahrnutí různých ekosystémových služeb, poskytuje optimalizační model bez prostorového hlediska srovnatelné výsledky s modelem, který tato hlediska zahrnuje. Primární hypotéza, že nemůže být dosaženo normální věkové struktury a těžební vyrovnanosti i v případě použití omezení týkající se přiřazování sečí, byla zamítnuta

Contrasting effects of environmental change on the radial growth of co-occurring beech and fir trees across Europe

Under predicted climate change, native silver fir (Abies alba) and European beech (Fagus sylvatica) are the most likely replacement species for the Norway spruce (Picea abies) monocultures planted across large parts of continental Europe. Our current understanding of the adaptation potential of fir-beech mixed forests to climate change is limited because long-term responses of the two species to environmental changes have not yet been comprehensively quantified. We compiled and analysed tree-ring width (TRW) series from 2855 dominant, co-dominant, sub-dominant and suppressed fir and beech trees sampled in 17 managed and unmanaged mixed beech-fir forest sites across Continental Europe, including Bosnia and Herzegovina, Germany, Italy, Romania and Slovakia. Dendroecological techniques that combine various detrending methods were used to investigate variation in radial growth of co-occurring fir and beech trees. Coincidental with peak SO2 emissions, the growth of silver fir declined between 1950 and 1980 at most sites, whereas beech growth increased during this period. Correspondent to a significant warming trend from 1990-2010, average beech growth declined, but silver fir growth increased. Long-term growth patterns and growth-climate sensitivity of fir and beech trees did not significantly differ between managed and unmanaged forests. Multi-decadal changes in the growth rate of all vertical tree classes were similar. In contrast to previous indications of limited drought susceptibility of beech mixed stands, this study suggests that the mixture of tree species in forest stands does not necessarily prevent growth depressions induced by long-term environmental change. Our results further imply that forest management does not necessarily alter their sensitivity to environmental changes.

decision support systems in Slovak forestry planning: a review Systémy na podporu rozhodovania v lesníckom plánovaní na Slovensku: prehľad

Abstract Project COST Action FP 0804 - FORSYS summarizes European experiences in developing and applying decision support systems for forest management. This paper introduces FORSYS methodology for the classification of current forest management problems and for the description of existing decision support systems. The paper identifies the general forestry planning problems that need to be solved in Slovakia, lists the DSS tools available in Slovakia and evaluate their ability for addressing the identified problems. Finally, the research needs and gaps in this field were identified. A comparison of the situation regarding decision support in Slovakia and both in Europe and neighbouring countries (Austria, Hungary) is introduced in order to justify the identified needs. The paper is focused on the overview of models, methods and knowledge management techniques which are available in Slovakia now. We found out that the Slovak decision support research follows the state in Europe with a significant time delay and a lack of adequate instruments for addressing the contemporary planning problems exists. Consequently, there is a strong need for the development and application of computer-based tools to support decision-making problems in forest management. Abstrakt Projekt Akcie COST FP 0804 - FORSYS zhŕňa európske skúsenosti v oblasti rozvoja a využívania systémov pre podporu rozhodovania v obhospodarovaní lesov. Predložený príspevok sa zaoberá metodikou FORSYS pre klasifikáciu súčasných problémov lesného hospodárstva a pre opis existujúcich systémov pre podporu rozhodovania. Identifikuje základné problémy lesníckeho plánovania, ktoré je potrebné riešiť na Slovensku, uvádza DSS nástroje ktoré sú k dispozícii a hodnotí ich schopnosť riešiť identifikované problémy. Na záver sú identifikované potreby výskumného riešenia a existujúce nedostatky v tejto oblasti. Na odôvodnenie zistených potrieb sa tiež uvádza porovnanie situácie v oblasti podpory rozhodovania na Slovensku so situáciou v Európe a susedných krajinách (Rakúsko, Maďarsko). Článok je zameraný na prehľad modelov a metód rozhodovania ako aj techník na manažment znalostí, ktoré sú aktuálne na Slovensku k dispozícii. Všeobecne možno konštatovať, že výskum v oblasti podpory rozhodovania na Slovensku síce sleduje stav v Európe, avšak so značným časovým oneskorením a výrazným nedostatkom vhodných nástrojov pre riešenie aktuálnych plánovacích problémov. V dôsledku toho existuje silná potreba pre vývoj a aplikácie počítačových nástrojov na podporu rozhodovania problémov hospodárenia v lesoch.

Cross-dating tree-ring series of living European beech by isochronic weather records

Abstract The main objective of the study is to facilitate cross-dating of sensitive tree-ring series from living European beech (Fagus sylvatica L.) trees in the absence of a regional chronology. The main idea lies in the preliminary dating of marker rings or ring patterns visually identified on the wood (before the ring-width measurements), which is independently validated through a moving correlation between a tentative reference chronology and instrumental climate records (after the ring-width measurements). Following the detection of low moving correlations, potentially misdated segments or series are re-examined and a new tentative reference chronology is constructed. The process is repeated as long as a higher correlation with climate is obtainable. The applicability of this method was investigated on three difficult-to-date sets of tree-ring series of beech trees which were growing at temperature- or precipitation-sensitive locations in under-canopy or canopy positions. A good ability of the combined method for the cross-dating was practiced on datasets almost impossible to cross-date by commonly used approaches. Highlighting the actual correlation of ring widths with climate in tree-ring series makes the cross-dating process more independent from human decisions, so the com-bined cross-dating has the potential to improve the reliability of various dendrochronological studies.

Structural analysis of the drivers and barriers to forest management in the Slovak regions of Podpoľanie and Kysuce

Abstract The paper presents an application of structural analysis in search of key drivers and barriers of forest management in two Slovak regions: Podpoľanie and Kysuce. A comparison with factors identified in selected European regions is also presented. First, various relevant factors affecting forest management were selected for both regions. The selections draw on the pool of primary data (structured in-person interviews) and secondary data (qualitative analysis of national and European documents). Second, factors were grouped according to the STEEP categories (Society, Technology, Economy, Ecology, and Policy). Subsequently, factors were rigorously assessed by the regional stakeholders in participatory workshops, and their answers were analysed by structural analysis with the help of Parmenides EIDOS™ software. The results show that in both Slovak regions political, economic, and ecological factors dominated over social and technological factors. The comparison with selected European regions revealed that in the Slovak and other European regions, the Policy category dominated due to having the highest number of factors and their overall impact on forest management. In contrast, the least important societal domain was Technology in both the Slovak and other European regions. However, while stakeholders across the selected European regions perceived the Society domain as significant, stakeholders in both Slovak regions perceived the Economy and Ecology domains as more significant.