effect of european black alder monocultures on the characteristics of reclaimed mine soil

the effect of european black alder (alnus glutinosa l.) on the contents of carbon and nitrogen,exchangeable base cations, and plant available forms of phosphorus in the reclaimed mine soils formed bywaste deposition from opencast lignite mines was researched in central serbia. it was concluded that thegreatest part of dead organic residues reaching the soil under european black alder monocultures was liable torapid decomposition into end products. this was the consequence of a narrow c/n ratio in the european blackalder litterfall which amounted on average to 12.77 in the study monocultures. only a small part of organicresidues was transformed into humus. on that account, european black alder monocultures did not have amajor impact on the accumulation of organic carbon and total nitrogen in the soil. the content of carbon in thesurface layers accounted for 1.55-1.57%, and the content of nitrogen to 0.085-0.132%. fast mineralisation oforganic matter, and thus also of the organic forms of nitrogen, resulted in the surplus of soil nitrates, whichwere liable to washing through the soil. nitrate movement resulted in the soil leaching and the movement ofbase cations, primarily calcium, to the deeper layers of the solum. the total soil phosphorus content was low,and also the level of plant available forms. a significant portion of total phosphorus in the surface layers of thereclaimed mine soils was composed of its organic forms.