The red heartwood of beech is responsible for decreasing the market value of the most important deciduous tree species of central Europe. The aims of this study were: (i) to verify the hypothesis that stand age affects the occurrence and metamorphosis of red heartwood in beech; and (ii) to quantify the economic loss due the sale price reduction of timber affected by red heartwood. Seven even-aged beech stands of different age (87, 100, 105, 110, 115, 132, and 145 years) were selected in Slovakia, and 213 trees were cut into 961 pieces of assortments which were evaluated for the presence, form and extension of red heartwood. The economic loss caused by red heartwood was determined as the difference in price between the actual and the potential quality grades of assortments. The results confirmed that stand age significantly influence the occurrence, development, and metamorphosis of red heartwood. The average loss in timber sale price caused by red heartwood varied between 0.76 and 28.04 € m-3, depending on age and form of red heartwood, with more severe losses in stands older than 110 years. To reduce the incidence of beech red heartwood in Central Europe, a reduction of the rotation period should be considered, as well as the adoption of suitable silvicultural practices in aged beech stands.

Forest cover influences not only the amount of surface runoff, but also its quality. The concentrations of chemicals in surface runoff differ between forest catchments and non-forest catchments (agricultural areas). The authors investigated the chemical compositions of surface runoff in two small neighboring catchments (forest, non-forest), by analyzing and summarizing data over a period of 26 years from 1986 to 2012. During this period, the stock and absorption area of forest stands increased, air quality improved, the agricultural landscape was partly regenerated, and global climate change became apparent. The authors observed differences in surface runoff between forest- and non-forest catchments. However, these differences were not mainly caused by the influence of the forest cover, but by changes in agricultural land management. Since 2006, agricultural land has been managed without the use of artificial fertilizers, which reduced the contents of pollutants in surface runoff from the non-forest catchment. The existence of the forest as such excludes or noticeably eliminates the use of fertilizers and chemical substances that affect water quality.

The aim of the article is to find out if there is a difference between amount of litter-fall in hornbeam-oak-pine stands according to regeneration (naturally and artificially) and age of the stand (middle-aged, mature). We analysed the annual dynamics of litter-fall (litter) and its fractions (needles of Scots pine; leaves of common oak; leaves of associate species; twigs; bark; pine cones; acorns of common oak; seeds of other species; acorn cups, winged seeds; lichens, mosses) in middle-aged hornbeam-oak-pine stands which were regenerated naturally or artificially on the cutover sites following two-stage uniform shelterwood felling and clearcutting, as well as in a mature parent stand (control plot) in the Lviv Roztoche region. Two peaks of organic matter fall have been revealed on both the control plot and the experimental plots: the largest one in October and much lower in May. It was found that the annual mass of litter was 5.8 - 6.6 tons per hectare, the annual weight of litter in the middle-aged hornbeam-oak-pine stands was greater than in the mature stands. Annual dynamics of certain fractions of litter in the stands is preconditioned by the specificity of functioning of the relevant bodies of the trees.

The aim of the paper is to analyze and evaluate the long-term impacts of the transition from agricultural production to ecological farming on the quality of runoff water in small catchments based on the analysis of water samples in the period 1986–2022. A total of 111 samples were analyzed. The following parameters were determined: nitrites, nitrates, chlorides, sulphates, phosphates, iron, coliform bacteria, and pH. Until 2006, the catchment was intensively managed by using artificial fertilizers and chemical preservatives. Since 2006, the catchment has been managed exclusively in an ecological way without the use of fertilizers and chemicals. The results of the analysis confirmed the positive impact of the transition of agricultural production to ecological farming, especially in the parameters of nitrates and chlorides. The greater use of organic fertilizers has caused an increase in coliform bacteria in the runoff water. The long period of the research also caused it to be possible to assess the impact of other potential factors. Changes in pH parameters and sulphates indicate an improvement in air quality. Changes in nitrite and iron parameters may indicate climate change associated with more intense precipitation activity.

Water reservoirs are an important source of drinking water in Slovakia and are managed under the control of regional water utility enterprises. These enterprises face increasing challenges due to ecological pressures, land use conflicts, and technological constraints. This paper investigates the external factors that influence the management of drinking water reservoirs and their implications for water quality. Using the PESTLE framework (Political, Economic, Social, Technological, Legal, and Environmental), we analyse case studies from four Slovak reservoirs: Málinec, Turček, Nová Bystrica, and Hriňová. The data was collected in 2025 using structured interviews with representatives of four water management enterprises and forest managers (three respondents from Málinec, Turček and Hriňová, two respondents from Nová Bystrica), whose forests surround the chosen water reservoirs. The analysis reveals that forest management, stakeholder relations, extreme climate events, and outdated infrastructure significantly affect water treatment efficiency and operational costs. While national water policy provides a uniform regulatory framework, the case studies demonstrate that local conditions and governance dynamics strongly impacts the water management utilities and its performance in drinking water treatment.

The increasing competition for nature resources usage emerges the highest pressure on ensuring forest ecosystem services. The goal of the paper is to demonstrate that the quality of the water is the forest's positive external effect and the value of this service. The paper points to possibilities for valuation methods based on costs for drinking water treatment in forested water catchments near three water reservoirs in Slovakia. The value of this service in the case of analysed water reservoirs in Slovakia is in the range of 1.67 to 8.90 € ha-1 year-1. With the alternative payment of a water cent for each m 3 of drinking water consumed, the calculated value per ha of forest in water reservoir catchment is in the range of 3.82-12.19 € ha-1 year-1. The valuation of water quality and quantity regulation enables to compensate forest enterprises for ensuring these services and is also the base for implementing effective forest policy instruments.