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The study presented a bioeconomic modelling approach for an uneven-aged mixed forest management planning. Regression models for transition (increment), and ingrowth (regeneration) used the National Forest Inventory (NFI) of Slovakia and regional inventory data. Mortality was based on salvage logging records. Models were specific for five tree species within three forest types (FT) (oak with hornbeam and beech, beech, mixed fir-beech-spruce). Net timber prices were calculated with regard to stem quality. Tree growth depended on crown characteristics. The regression models were adjusted to three main geobiotope (GBT) sites per FT. Forest growth was simulated with the density-dependent stand-level matrix transition model. Financial optimisation of harvest was sensitive to an interest rate. Long-time optimisation stabilised in a steady state equilibrium characterised by a stable diameter distribution. Target diameters were specific for site and tree species, and were highest for fir, a dense crown, a good stem quality, and a lower interest rate. Standing timber volume varied from 150 m3 ha–1 (oak forests, 2% interest rate) to 400 m3 ha–1 (beech and fir-beech-spruce forests, 0.5% interest rate). Harvested volume varied from 38 to 93 m3 ha–1 per 10 years, stand basal area (ba) varied from 19 to 36 m2 ha–1 depending on the site, timber price, and interest rate. The discussion pointed out that the relative low volume of the oak FT resulted from the light-demanding characteristics of oak. The mean of oak mosaic structures was lower compared to the high level of more storeys present in the single tree selection structures in beech and mixed fir-beech-spruce forests.

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]

• 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]

Based on a literature review and on a new bioeconomic modelling approach, we investigated whether or not clear-cutting and mono-species forests are the optimal silvicultural strategies under the presence of risk. The model reflects a risk-avoiding attitude and builds upon portfolio theory. The selected tree species and the timing of regeneration harvests constitute a total of 22 management alternatives. Optimal area fractions of the alternatives were combined at the stand level to find the maximum value at risk (VaR, annualized net present value exceeded with probability of 0.99). Relevant uncertainties were integrated via Monte Carlo Simulation and bootstrapping. The results showed a maximum VaR for a highly diversified treatment combining 42 per cent Norway spruce and 58 per cent European beech and included area fractions with regeneration harvests from age 50 to 120 years. This treatment avoids clear-cutting and a mono-species forest composition. It uses tree species diversification and extends the regeneration period over 70 years to diversify hazard and price risks. The resulting scenario may be called ‘near-natural’ and emerges as the optimal choice, particularly for cautious, and thus risk-avoiding forest owners who do not have the opportunity to diversify risks by means of large-scale forest properties. [ABSTRACT FROM AUTHOR]