Impact of fine woody debris on surface water run-off

The presented study focuses on the impact of deadwood on surface water run-off, which was examined under laboratory conditions. In total we performed 600 rainfall simulations with harvest residues (wood with maximum length of 1 m and maximum diameter of 7 cm) that were either fresh (collected immediately after the harvest) or old (3 years and 3 months after harvest). The research analysed the impact of different values of deadwood coverage (15%, 30%), direction of its spatial arrangement (along the contour line, along the slope, random), moisture and decay stage (fresh, old) of deadwood situated on the slope with different inclinations (1% and 25%) under different rainfall intensities (5, 20, 40, 80 and 150 mm/h) on water run-off. The obtained results confirmed the significant impact of terrain slope on water run-off. The run-off from 1% slope represented 32% of the run-off observed from 25% slope. From the point of deadwood coverage, we found the fastest run-off at the smaller coverage of 15%, while in the case of 30% deadwood coverage, the run-off was only 75% of the value for 15% coverage. Decay stage of deadwood had also a significant impact on water run-off, which was by one third lower in the case of old deadwood in comparison to fresh wood. The water run-off was the fastest in the case of the spatial arrangement of deadwood along the contour line, and the slowest in the case of randomly distributed deadwood in all directions.

Automated summary

The study examined the impact of deadwood on surface water run-off through laboratory simulations. Various factors such as deadwood coverage, spatial arrangement, moisture, decay stage, slope inclination, and rainfall intensity were analyzed. The results showed that slope inclination significantly affected water run-off, with 1% slope experiencing only 32% of the run-off observed from 25% slope. The fastest run-off occurred with 15% deadwood coverage, while 30% coverage resulted in only 75% of the run-off compared to 15% coverage. The decay stage of deadwood also played a significant role, with old deadwood leading to one-third lower run-off than fresh wood. Deadwood arranged along the contour line resulted in the fastest run-off, while random distribution led to the slowest run-off.