Significant areas of Latin America, and especially of Chile, have been forested with forest plantations to provide timber and fiber and to decrease soil erosion after deforestation. Despite their potential contribution to reducing erosion processes, the magnitude of this decline has not been adequately assessed. In this study, we estimated soil loss and mobility for one year on steep hillslopes using the traditional erosion‐pin approach at five micro‐catchments planted with Pinus radiata with different stand ages and compared them to an adjacent secondary broadleaf Nothofagus sp. native forest. Annual net soil loss (ASL) positively correlated with cumulative rainfall (R² = .49, p < .001). ASL averaged 65.03 ± 9.8 mg ha⁻¹ yr⁻¹, with the lowest ASL in the natural forest with 21.4 ± 3.1 mg ha⁻¹ yr⁻¹ and the highest in one of the 1‐year‐old plantation micro‐catchments (88.9 ± 9.3 mg ha⁻¹ yr⁻¹). ASL under plantation stands of different ages displayed no significant differences. All areas showed similar net soil loss index values, averaging 83.0 ± 1%, suggesting that most of the sediment left the hillslope. The RUSLE model predicted ASL moderately well across all sites and conditions (0.41, p = .018), but it tends to underestimate ASL, particularly for native forests. On average, soils on hilly terrain under plantation forest may suffer losses up to four times greater than natural forests. The latter stresses the need to improve our understanding of erosive processes that may be still active under planted forest, and to better assess the effect of management practices on soil erosion, particularly on previously highly degraded and erodible soils.

中文翻译：

---

智利中南部沿海地区松树人工林和天然落叶林的坡地土壤侵蚀和迁移

拉丁美洲的重要地区，尤其是智利的重要地区，已植树造林，以提供木材和纤维并减少森林砍伐后的土壤侵蚀。尽管它们对减少侵蚀过程有潜在的贡献，但这种下降的幅度尚未得到充分评估。在这项研究中，我们使用传统的侵蚀钉方法在五个不同林分年龄的辐射松种植的微型集水区，使用传统的侵蚀钉方法估算了一年的土壤流失和迁移，并将其与相邻的次生阔叶Nothofagus sp进行了比较。原生森林。年净土壤流失量（ASL）与累积降水量呈正相关（R ² = .49，p  <.001）。ASL平均65.03±9.8毫克公顷^-1 yr ^-1，天然林中的ASL最低，为21.4±3.1 mg ha ^-1 yr ^-1，在1年人工林小集水区之一中最高（88.9±9.3 mg ha ^-1 yr ^-1）。不同年龄的人工林下的ASL没有显着差异。所有地区都表现出相似的净土壤流失指数值，平均为83.0±1％，这表明大部分沉积物都离开了山坡。RUSLE模型在所有场所和条件下均能很好地预测ASL（0.41，p= .018），但它往往会低估ASL，尤其是对于原生森林而言。平均而言，人工林下丘陵地带的土壤损失可能是天然林的四倍。后者强调有必要增进我们对人工林下仍可能活跃的侵蚀过程的理解，并更好地评估管理措施对土壤侵蚀的影响，特别是对先前高度退化和易侵蚀的土壤的侵蚀。