Hydrological responses of pine needle litter to rainfall erosional processes on Chinese karst hillslopes

Abstract

Native vegetation restoration, such as pines, is an effective measure for mitigating soil erosion. However, the impact of pine needle litter on runoff, soil erosion, and hydrological responses on karst hillslopes remains unclear. This study investigated these factors during the rainy season from June to August 2021 under six distinct treatments (flat, gentle, and steep slopes with and without pine needle coverings). The results showed that pine needle litter significantly increased the soil water content, particularly on steeper slopes, by improving the water-holding capacity. It also substantially reduced runoff (by 23.8%) and soil erosion (by 92.5%). The critical rainfall threshold for generating runoff did not occur in the pine needle covering treatment, whereas it was 19.3 ± 8.8 mm in the bare soil treatment under wet conditions. These findings highlight the efficacy of pine needle cover in mitigating runoff and soil erosion in karst areas, suggesting it as a sustainable alternative against erosion, and underscoring the importance of pine plantations in degraded soil restoration efforts.

Keywords:

• karst hillslope
• pine needle covering
• rainfall threshold
• soil water content
• runoff
• soil erosion
• degraded soil restoration

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Supplementary material

Supplemental data for this article can be accessed online at https://doi.org/10.1080/02626667.2024.2349261.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

We acknowledge and are grateful for the financial support provided by the National Natural Science Foundation of China through grant no. 42067004, Guizhou Provincial Science and Technology Foundation (YQK[2023]005), and China Scholarship Council.