Key Laboratory of Forest Ecology and Environment of National Forestry and Grassland Administration, Research Institute of Forest Ecology, Environment and Protection, Chinese Academy of Forestry, Beijing 100091, China.
Key Laboratory of Forest Ecology and Environment of National Forestry and Grassland Administration, Research Institute of Forest Ecology, Environment and Protection, Chinese Academy of Forestry, Beijing 100091, China.
Sci Total Environ. 2021 Aug 25;784:147120. doi: 10.1016/j.scitotenv.2021.147120. Epub 2021 Apr 16.
Forest management practices play an important role in soil water conservation. However, the soil water-holding capacity and associated drivers under different management practices remain uncertain, especially when the precipitation varies substantially at the regional scale. Here, we used hydrogen stable isotope to explore the contribution of rainfall to soil water (CRSW) under light, moderate and heavy precipitation in Pinus massoniana plantations with multiple management practices (pure stand, mixed stand, understory removal, light-intensity thinning and high-intensity thinning) in subtropical China. We further used variation partitioning analysis and structural equation modeling to identify the dominant driver affecting CRSW. Our results showed that after light rainfall, the highest CRSW (28.7%) was found in the high-intensity thinning plantation. However, after heavy rainfall, the high-intensity thinning plantation received the lowest CRSW (43.3%), while the mixed stand showed the highest CRSW (67.1%). These results demonstrated that the mixed stand of P. massoniana had a stronger capacity for soil water conservation, whereas high-intensity thinning showed poorer capacity. Furthermore, our results revealed that plant properties (i.e., tree, root and litter biomass) were the dominant controls of the CRSW under light rainfall, while soil properties (i.e., bulk density, total porosity, field capacity) were the primary drivers under moderate and heavy rainfall, indicating that the determinants influencing plantation capacity for intercepting rainfall vary with different levels of precipitation. These results highlight the importance of the level of precipitation in determining the dominant driver of CRSW. More importantly, these results suggest that the mixed stand, rather than high-intensity thinning, was better forest management since the former has a higher capacity for intercepting heavy rainfall.
森林经营措施在水土保持中起着重要作用。然而，在不同管理措施下，土壤持水能力及其相关驱动因素仍不确定，特别是在区域尺度上降水变化较大的情况下。在这里，我们使用氢稳定同位素来探索在亚热带中国具有多种管理措施（纯林、混交林、林下清除、轻度疏伐和高强度疏伐）的马尾松人工林在轻、中、重三种降水条件下，降水对土壤水的贡献（CRSW）。我们进一步使用方差分解分析和结构方程模型来确定影响 CRSW 的主要驱动因素。结果表明，在小雨后，高强度疏伐林的 CRSW 最高（28.7%）。然而，在大雨后，高强度疏伐林的 CRSW 最低（43.3%），而混交林的 CRSW 最高（67.1%）。这些结果表明，马尾松混交林具有更强的土壤保持能力，而高强度疏伐林则较差。此外，我们的结果表明，在小雨条件下，植物特性（即树木、根系和凋落物生物量）是 CRSW 的主要控制因素，而在中雨和大雨条件下，土壤特性（即容重、总孔隙度、田间持水量）是主要驱动因素，这表明影响林分截留降雨能力的决定因素因降水水平的不同而不同。这些结果强调了降水水平在确定 CRSW 的主要驱动因素中的重要性。更重要的是，这些结果表明，与高强度疏伐相比，混交林是更好的森林管理措施，因为前者具有更高的截获大雨的能力。
