Literature review on the effects of biochar on soil quality has shown that biochar amendment to forest soil brings many benefits, such as increased organic matter content, water and nutrient retention (FC, CEC), and soil aggregate stability. Potentially soil vulnerability to erosion processes and greenhouse gas emissions are reduced. Studies on the effect of biochar on seed germination, as well as on seedling and tree growth, have shown an increased, reduced or neutral effect. The effects of biochar depends on the biochar characteristics, dosage and activation; on the soil type and climatic conditions of the site; as well as on the plant type and vegetation phase. In forestry, biochar soil amendment could be beneficially used especially in degraded areas (soil low in organic matter content, contaminated soil), for forest restoration after ecological disturbances, or in restoration of log landings, skid trails and abandoned forest roads. In the experimental part of the thesis, we found that biochar had negative effect on germination of empress tree seeds (Paulownia tomentosa (Thunb.) Steud.), as 12 % fewer seeds germinated compared to control. But it had positive effect on call growth, as they were on average 18 % higher in comparison to control without biochar amendment. As expected, until the completion of the thesis, we did not find statistically significant differences in common beech (Fagus sylvatica L.) growth (height and thickness) in the pot experiment. However, we found significant differences in soil properties between treatments. The addition of biochar to soil increased the content of organic C (for 5,9 %), water-holding capacity of soil (by 12.3 % for FC and 7.8 % for WP); and CEC (for 6,0 mmolc/100g) compared to control soil.
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