Some Results of Stationary Sample Plot for Intensive Monitoring of Forest Ecosystems in Vitinya Area

Results are presented for the chemical composition of the forest litterfall and lysimetric waters of Cambisols from the intensive monitoring stationary sample plot of the forest ecosystems. Litterfall (litter biomass fraction) had fallen on the soil surface with acid reaction, which in the period 2011 - 2018 varied from 5.1 to 5.4. The established contents of calcium (6.9 mg.g-1 ), magnesium (0.52 mg.g-1 ), potassium (3.58 mg.g-1 ), nitrogen (7.28 mg.g1 ) and phosphorus (0.55 mg.g-1 ) were low and those of manganese (1754 µg.g-1 ), iron (185 µg.g-1 ), copper (11 µg.g-1 ) and zinc (36 µg.g-1 ) were high. The lysimetric waters in the surface horizon were very strongly acidic – pHH2O= 4.6. The amounts of all the tested parameters in them were very low – dissolved organic matter (8.0 mg.dm3 ), potassium (2.6 mg.dm3 ), calcium (5.7 mg.dm3 ) and others. Only the content of manganese was increased, which in some years exceeded the maximum value pointed in the literature for the European forests. It is assumed that degradation processes take place in the mineral part of the soil which lead to its impoverishment of macro and microelements.