DECOMPOSITION OF PINE-LITTER ORGANIC-MATTER AND CHEMICAL-PROPERTIES OF UPPER SOIL LAYERS - TRANSECT STUDIES

The relationship between Seats pine litter decomposition rate and some chemical properties of the upper soil layers and litter (contents of iron, manganese, zinc, copper, lead, mercury, nickel and chromium) was determined. For the metal content in the organic-mineral horizon of s oils, the strongest correlation was between needle decomposition and c opper (r=0.90), zinc (r=0.90), iron (r=0.83), and nickel (r=0.85) conc entrations. For the metal content of litter, the strongest correlation s were between needle decomposition and nickel (r=0.89), iron (r=0.83) , zinc (r=0.80), and lead (r=0.82) concentrations. For mixed-litter de composition and litter heavy metal concentrations, the highest correla tions were with nickel (r=0.72), iron (r=0.71), zinc (r=0.66), and lea d (r=0.68). There were no significant correlations between the rate of decomposition of wood or cones and the litter concentration of metals other than chromium. In some cases, the correlations between decompos ition rate and metal concentration were positive. Two out of six signi ficant correlations between needle decomposition and the concentration of metals in litter were positive. For mixed litter decomposition, th e five significant correlations included two that were positive. lit b oth cases, decomposition responded positively to the presence of iron and lead. Comparing decomposition rates with the level of soil metal c ontent, all five significant correlations with needle decomposition we re positive; for mixed-litter decomposition, only one significant corr elation was positive. (C) 1997 Elsevier Science Ltd. All rights reserv ed.