Decomposition and element concentrations of silver birch leaf litter as affected by boron status of litter and soil

摘要

Inadequate boron (B) nutrition can affect the structural integrity and chemical composition of plant tissues. The changes in mass and element concentrations were studied using silver birch (Betula pendula Roth) leaf litter from seedlings grown with or without added B (B_litter+ or B_litter−). The litter was produced in a growth room, and it was incubated in either B fertilised or control forest plots (B_soil+ or B_soil−) between the moss and humus layers in two Norway spruce stands for 13 months. Additionally, the field decomposition experiment included long-term N and P application treatments (N_soil and P_soil). B_litter+ somewhat reduced the remaining litter mass. In contrast, B_soil+ increased it, possibly because of lower soil pH. The +N_soil treatment reduced the remaining mass. B_litter+ increased the remaining P, S, Cu, Cd, Ni and Zn but reduced Pb. Remaining B was high in the B_litter– which also accumulated B from soil. B_soil increased remaining Ca, Cd, Mg, Na, Pb, and slightly reduced N (in N fertilised plots). These changes in decomposition and element release have a potential to affect nutrient, carbon, and heavy-metal cycles in areas where B deficiencies are common, and where B fertilisation is practised.