Litterfall, litter decomposition, and carbon storage of Pinus densiflora and Quercus variabilis stands in South Korea

Abstract

The quantification of carbon (C) storage of different stand types is a key component for understanding forest C cycles and potential climate change. This study evaluated the effects of stand types on litterfall, litter decomposition, and forest C storage in Pinus densiflora S. et Z. and Quercus variabilis Blume stands in southern Korea. The aboveground C storage by tree biomass was not affected (P > 0.05) by stand types (P. densiflora: 79.49 Mg C ha(-1); Q. variabilis: 96.37 Mg C ha(-1)). However, total C inputs by litterfall were significantly higher for the P. densiflora (4,473 kg C ha(-1) year(-1)) than for the Q. variabilis (2,633 kg C ha(-1) year(-1)) stands. Organic C over litter decomposition processes was more rapidly mineralized in the leaf litter of Q. variabilis than in needle litter of P. densiflora, but C storage on the forest floor was not affected by different stand types. Total soil C storage was not significantly different between the Q. variabilis (55.71 Mg C ha(-1)) and P. densiflora (80.49 Mg C ha(-1)), whereas the C concentrations at each soil depth were significantly higher in the P. densiflora than in the Q. variabilis stands, except for the subsurface depth (30-50 cm). These results indicate that the distribution of C storage in P. densiflora and Q. variabilis stands is less susceptible to interspecific differences, such as litterfall inputs and decomposition rates.