Litterfall and litter chemistry change over time in an old-growth temperate forest, northeastern China

Abstract

• Litterfall and litter chemistry are key factors for the assessment of forest floor properties. A long-term study on litterfall, litter chemistry and forest basal areas was carried out in an old-growth temperate forest, northeastern China.• The objective of this study was to test whether forest floor properties in the old-growth forest remain relatively constant.• Litterfall increased significantly over the past 27 y but litterfall of various litter components showed different temporal trends. Changes in proportions of various litter components, combined with the inherent chemistry differences among them, made litter carbon (C): nitrogen (N) and lignin:N ratios increase at an average rate of 0.19 and 0.16 per year, respectively, suggesting a decreasing trend in the forest floor C and N cycling rates. Changes in dominant tree species biomass significantly affected their corresponding foliar litter production and proportions in the total litterfall and therefore played a dominant role in regulating the developing trends of litter chemistry and quantity in this forest floor.• Our study indicated that forest floor properties in the old-growth forest still showed a directional change and this was mainly caused by the intrinsic changes rather than yearly climatic fluctuation.