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The aim of the study is to quantify the impacts of a possible transition to close-to-nature forestry in Slovakia and to compare the expected development of the total volume production, growing stock, merchantable wood increment and harvesting possibilities of forests in Slovakia with current conventional management using the FCarbon forest-growth model and available data from the Information System of Forest Management. The subject of the study was all forest stands available for wood supply (FAWS). The simulations were run in annual iterations using tree input data aggregated over 10-year-wide age classes. The calculation of wood increments was based on available growth models. In the business-as-usual (BAU) scenario, stock losses were based on the actual intensity of wood harvesting in the reference period 2013–2022. In the scenario of the transition to close-to-nature forest management, the losses were specifically modified from the usual harvesting regime at the beginning, to the target harvesting mode in selective forest at the end of the simulated period. With the modelling method used, a gradual increase in forest stocks occurred in both evaluated scenarios in the monitored period, namely by 10% in the case of BAU and by 23% in the case of close-to-nature forest management until 2050. In absolute mining volume, CTNF is by 5–10% lower than BAU management, with the difference gradually decreasing. The results show that the introduction of close-to-nature forest management will temporarily reduce the supply of wood to the market, but this reduction will not be significant and will be compensated by a higher total volume production, and thus also by increased carbon storage in forests. [ABSTRACT FROM AUTHOR]

• Significant shifts in radial growth of four European tree species during the past hundred years. • Fir showed the greatest recovery, but was found less resistant than beech. • Spruce found to be the least resilient and least resistant in the region. • Long-term BAI growth not affected by species mixture. • A small, but statistically clear effect of species diversity on BAI growth was revealed. Norway spruce (Picea abies), European beech (Fagus sylvatica), silver fir (Abies alba) and Scots pine (Pinus sylvestris) typically co-occur in European forests, but show contrasting response to climate and environmental change. Sustainable forest management therefore depends on species- and regional-specific information. Here, we use tree-ring width measurements of 334 beech, 280 fir, 144 spruce and 63 pine trees from 75 inventory plots in Slovakia to assess the predominant factors that control radial stem growth of Europe's economically most important forest species. All four species exhibit significant shifts in stem growth over the past 100 years. Ring width patterns were, however, not significantly affected by tree species diversity and site elevation. The resistance, resilience and recovery of all species to the extreme summer droughts between 1950 and 2003 suggest that spruce is the species most unsuitable for the predicted warmer and drier future. Silver fir may benefit from warmer conditions, although we cannot conclude that it will not suffer from predicted increased frequency of climate extremes. Forest management in this locality should aim to avoid significant loss of forest cover by replacing Norway spruce monocultures with mixed stands of silver fir and European beech. [ABSTRACT FROM AUTHOR]

Steadily increasing damage to Norway spruce forests in Europe has caused researchers and managers to consider whether these forests can be converted to more stable ecosystems. In a central European mountain region, we investigated whether management systems (MSs) specified by regional stakeholders provide sound alternatives to the currently applied management. We used the forest model Sibyla to explore whether the tested MSs differ in their sensitivity to climate change in terms of altered biomass production, stand structure, forest damage, and financial outcome. The tested MSs were no-management (NM), currently applied management (BAU), and management based on the preferences of forest managers (FM) or on the preferences of other stakeholders (OSH). With NM, spruce remained dominant during the simulation period 2010-2100, and the rate of damage significantly increased. Spruce also remained dominant with FM, while the abundance of non-spruce species significantly increased with BAU and OSH. The rate of salvage logging converged at 50% of the total harvest for all MSs up to 2050. Climate change reduced biomass production (−15%) with all MSs but had a negligible effect on biodiversity indicators. The average initial value of the simulated stands was 20,000 € ha and the nominal value in 2100 was between 1900 and 10,900 € ha. The Net Present Value calculated with the 2% interest rate was negative during the whole simulation period (−5600 to −18,500 € ha in 2100). Effect of climate change on all financial indicators was negative. Our findings indicate that secondary spruce forests are highly vulnerable and that the systems proposed by both forest managers and other regional stakeholders failed to significantly reduce forest damage and stabilize forest production. [ABSTRACT FROM AUTHOR]

• An unique database on dynamics of eleven beech-dominated old-growth forests in Central Europe since 1970 to 2019 utilised. • The radial increment of beech trees increased whereas the natural mortality decreased significantly during the study period. • European beech appears to be the most vital and competitive species from sub-mountain to mountain zones in Central Europe under ongoing climate change. • Admixture of other species can contribute to profitability of close-to-nature forest management based on European beech. European beech is the dominant native tree species in sub-mountain and mountain zones of the European continent and provides multiple ecosystem services to European society. However, the mountain zone is strongly affected by environmental change. Here, we explore the long-term natural dynamics of European beech-dominated old-growth forests in the Western Carpathians, Central Europe. We use fifty-year measurements of forest stand dynamics from eleven nature reserves strictly protected from any management (some of them included in the UNESCO natural heritage program). The study sites cover a typical range of natural conditions of the beech-dominated altitudinal zone in the Western Carpathians. The database includes long-term pair-wise non-destructive measurements of nearly 3.000 beeches from 1970 through 2019. We aim to investigate three crucial processes of beech forest dynamics: increment, ingrowth, and mortality of beech trees. The results, besides expected interactions, indicated a statistically significant change in radial increment and tree mortality during the study period. The radial increment increased, whereas tree mortality decreased during the past decades. Our findings indicate that European beech has strengthened the role of the most vital and competitive tree species in the elevational range from sub-mountain to mountain zone of Central European mountains during the last 50 years. The species increases the potential of enlarging its current distribution and outcompeting other species at the upper as well as lower elevational range edges. The assumed reasons for such development considering postglacial vegetation development in Europe and upcoming climate change are discussed. Possible implications and ways how to utilize the observed findings in close-to-nature forest management are suggested. [ABSTRACT FROM AUTHOR]

Chronic browsing and inappropriate stand management are often discussed as causes for recruitment failure of tree species in temperate mixed uneven-aged forests. Continuous cover forestry is thought to produce conditions that are conducive to the recruitment of native shade-tolerant and browse-sensitive tree species such as silver fir (Abies alba Mill.). This study used density-dependent matrix population models parameterized for three maintypes of fir forests in Europe (53 048 measured trees from 3183 permanent sample plots) to project the effects of Business- As-Usual uneven-agedmanagement (BAU) andthree alternativemanagementscenarios (Non-Intervention (NON), Profit Maximization (MAX) and stand management optimized for increasing recruitment (CONS)) on fir population dynamics over 100 years. BAU, MAX and, particularly, CONS improved the population parameters if natural recruitment was sufficient regardless of site, current and historical logging and transient and equilibrium growth rates under NON. In chronically browsed and recruitment-limited fir populations with transient and equilibrium growth rates <1 under NON, the demographic ageing of fir can only be halted temporarily if silviculture is optimized for conservation, but none of the scenarios can prevent fir from decline. Our results suggest that a number of uneven-aged silvicultural systems, including more profit-oriented, can improve the demography of fir in central European mountain forests. However, theyare not apragmaticmethodto conserve firwhenapopulation suffers from limited recruitment that causes an unmanaged population to decline. [ABSTRACT FROM AUTHOR]

Abstract: A new modeling approach which combined survival probabilities for spruce with financial optimization showed a considerably reduction in financial risk in spruce (Picea abies [L.] Karst.) stands with an admixture of a 20% proportion of beech (Fagus sylvatica L.). The admixture enhanced the stability of the spruce component against natural hazards, such as storm or insect damage. Here, these new survival investigations were integrated into a bio-economic modeling approach called silvicultural economics. A new failure model which includes the benefits of ecological interactions for decreasing hazard risk for spruce was developed. The modeling technique is based on Monte-Carlo-Simulation and on simultaneous portfolio optimization of management strategies under risk. Area proportions were allocated as decision variables to each tree species and to regeneration harvests at various points in time in order to achieve the maximum financial return given a predefined, acceptable risk. The simultaneous optimization led to a mixed – and, through long regeneration periods – to an uneven-aged forest stand, for almost all predefined risk-levels. In addition, for a selection of possible even-aged tree species compositions, a stand-level mixture (including the species interactions of the new model) was compared with the same species proportion at the stand level, but consisting of two separated parts of spruce and beech (thus excluding species interactions). For all even-aged and interacting mixtures that were investigated, a higher expected return and a lower financial risk were achieved when compared to the identical even-aged mixture proportions without interactions. When the timing and distribution of regeneration harvests was also optimized (as opposed to using a clear-cut strategy) there was a slight loss in financial return, but the reduction in risk was even greater, given the same tree species proportion – especially in cases with a low beech admixture. Compared to the simulation which excluded the stabilizing effect of beech on spruce, the variant with interacting tree species allowed for higher spruce proportions and shorter regeneration cycles for the same acceptable risk. [Copyright &y& Elsevier]