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Long-term human activities substantially altered floodplain regions of temperate Europe. Forest management and extensive changes in hydrology greatly affected natural floodplain soil properties, in which microbes play key roles. This study aims to assess the effects of human activities through a gradient of forest management intensity on soil microbial community (SMC), its biomass, activity, and structure. Soil chemical and physical-chemical properties were used to explain the general associations and within-site variation using principal component analysis (PCA), linear regression (LR) and linear mixed-effect regression (LMER) models. It was found that forest management application, regardless of its intensity, led to significant microbial biomass reduction. PCA revealed that microbial biomass, expressed as a sum of phospholipid fatty acids along with recalcitrant carbon fraction (ROC) best explained the variability in data. LR and LMER highlighted that bacteria are affected by floodplain forest management more than fungi, and that bacterial response to pH was highly diversified. Also, pH was identified as the best predictor of SMC structure and activity but not of its size. The study calls for further investigation in SMC interactions with ROC, soil-available Fe and Mn, and the role of redox-active metals in soil organic carbon degradation.

Paulownia spp. comes from South-East Asia, where there is a tradition of its cultivation. Social pressure, in favour of the use of renewable sources of energy and sustainable agriculture, is on the rise. In this context, agroforestry has become a significant topic of interest. Paulownia spp. could be one of the species utilized in this field. That is why, in 2014, the experimental agroforestry system, which was intended for the production of fodder for farm animals, and also for the production of saw timber, was established in one of the warmest areas of the Czech Republic. The aim of this research was to evaluate the production potential of Paulownia Bellissia®. The measuring of the heights and thicknesses, and the determination of the extent to which the plants were damaged, were conducted during 2017–2020. The plantation consisted of two plots, where the plants on the first plot (treated plants) were regularly irrigated and annually pruned and those on the second (reference plants) were not. The treated plants reached a mean annual increment of 1.6 m in height and 2.8 cm in diameter at breast height, but almost 80 % were sunscalded, whereas the reference plants reached only 1.1 m and 2.0 cm but remained undamaged. Most of the damaged plants were also infested with parasitic fungi Schizophyllum commune and Trametes hirsuta, while the occurrence of S. commune on plantations of Paulownia was found as one of the first discoveries in the Czech Republic.

Due to an increasing risk of further damage to forests, forest managers are considering introducing an alternative direction for their future development - via the cultivation of mixed forests. At middle altitudes in the Czech Republic, an oak-beech-linden stand is the most natural type, and we tried to answer three main questions: (i) How the various thinning types affect dendrometric parameters and quality of the stand; (ii) How long thinning works on this stand until it loses its effect; (iii) How the stand develops spontaneously after abandonment. This experiment was conducted at the Training Forest Enterprise in the Czech Republic in Drahanská vrchovina (highlands in central Moravia). In 1988, four plots were established in a 49-year-old stand where, in three of the plots, different types of thinning (crown, low and heavy crown) were performed, leaving one (reference plot) to develop naturally. The height, the height of the crown base and diameter at breast height (DBH) were measured, and the shape and quality of the trunk and crown were estimated on each tree. Measurements were carried out in 1989, 1994, 1999, 2005, 2010, 2015, and 2020. In the first 10 years, the DBH and height of the crown base did not show any differences, and the linden at the heavy crown plot outgrew the linden trees at the other plots in height. After these 10 years, the thickest linden, the tallest beech and linden, and the greatest height of the crown base of beech and linden were all found at the heavy crown plot. The shape and quality of the trunks and crowns of beech, oak and linden were similar in all plots (including the reference plot) during the entire experiment. After thinning, the plots were left to grow spontaneously. The heavy crown thinning removed a greater number of thicker trees at the middle level, thus supporting the trees growing in the lower part of the middle level and in the below level (i.e. the beech and linden). These trees then grew more quickly compared to the others, but their quality decreased, as did that of the others. Therefore, a forest left to grow and develop spontaneously is practically unusable for commercial purposes.