Effects of Thinning On Soil and Forest Floor Carbon Storage of Pinus Densiflora Stands in Central Korea.

The objective of this study was to investigate the effects of thinning on soil carbon (C) storage of Pinus densiflora stands in central Korea. Study stands were located in P. densiflora forests of central Korea [stand I (15-year-old), stand II (25-year-old), and stand III (55-year-old)] and thinned in 2008. Three plots with different thinning intensities by stand density were established within each stand (no thinning, control: 0%, light thinning, L: 30%, moderate thinning, M: 50%, heavy thinning, H: 70%). We measured the C storage of soil (30cm in depth) and forest floor in P. densiflora stands in 2009. C storage (ton C/ha) of soil and forest floor in thinned plots were higher than that in control plot only for the stand III: 55.5 for control < 57.6 for L, and 59.2 for H. On the other hand, C storage of soil and forest floor in the stand I and stand II were not different among thinning intensities: [48.5 for control, 62.8 for L, and 46.1 for M in the stand I], and [54.9 for control, 49.9 for L, and 52.8 for M in the stand II]. This result showed that the higher the stand age, the more C was stored in soil and forest floor according to thinning. We speculated that 1 year was too short to detect any consistent changes in C storage of soil and forest floor by thinning. Therefore, we need to investigate the change in C storage of soil and forest floor more than 1 year.