earticle

영어

Previous studies surmised that under-canopy dead branches in unmanaged/abandoned coniferous plantations could reduce throughfall kinetic energy (TKE); however, the effect of under-canopy dead branch pruning on TKE has not been clarified. We established two plots under the same stand density (2500 stems ha⁻¹) in abandoned Japanese cypress plantations: (1) one with dead branch pruning (plot 1, P1) and (2) the other with no dead branch pruning (plot 2, P2). Throughfall (TF) and TKE were measured on the weekly basis during the growing season using manual-type TF rain gauges and sand-filled splash cups, respectively. Results showed that other than dead branch structures, no other stand structures significantly differed between P1 and P2 (p < 0.05). Both stand-scale TF ratio (72.8% vs. 63.5%) and unit TKE (21.4 J m⁻² mm⁻¹ vs. 13.5 J m⁻² mm⁻¹) were higher in P1 than in P2. This implies that dead branches under the canopy had considerable impacts on raindrop fall velocity after passing through upper canopies in unmanaged/abandoned Japanese cypress plantations. Our findings clarified that under-canopy dead branches can mitigate soil erosion risk in such plantations and can provide new insights into forest management for soil conservation.