ABSTRACT Climate change has led to a focus on forest management techniques to increase carbon (C) sequestration as a mitigation measure. Fertilisation and increased removal of biomass have been proposed. But these and other forest practices may have undesirable effects on surface water quality. In naturally acid-sensitive areas such as much of Fennoscandia a concern is acidification due to acid deposition in combination with forest practices that increase the removal of base cations and leaching of nitrate (NO3). Here we apply the biogeochemical model MAGIC to the coniferous-forested catchment at Birkenes, southernmost Norway, to simulate the effects of forest fertilisation and harvest on soil and streamwater. The model was calibrated to the 40-year data for water quality, soil and vegetation and then used to simulate fertilisation and clearcutting of the mature forest by either conventional stem-only harvest (SOH) or whole-tree harvest (WTH). The 5 – 10-year pulse of NO3 following clearcut was larger with SOH than WTH. WTH causes larger acidification of surface water relative to SOH, due to greater depletion of base cations, N and C from the soil. The use of forestry as a climate mitigation measure should take into consideration the potential effects on soil and surface water quality.

中文翻译：

---

集约化林业作为气候缓解措施改变了低强度管理森林的地表水质量

摘要 气候变化导致人们关注森林管理技术，以增加碳 (C) 封存作为缓解措施。已经提出施肥和增加生物质的去除。但是这些和其他森林做法可能会对地表水质量产生不良影响。在自然酸敏感的地区，如芬诺斯坎迪亚的大部分地区，人们担心酸沉积导致酸化，再加上森林实践会增加碱性阳离子的去除和硝酸盐 (NO3) 的浸出。在这里，我们将生物地球化学模型 MAGIC 应用于挪威最南端 Birkenes 的针叶林集水区，以模拟森林施肥和收获对土壤和河流水的影响。该模型根据 40 年的水质数据进行校准，土壤和植被，然后用于模拟通过常规仅茎收获 (SOH) 或全树收获 (WTH) 对成熟森林进行施肥和砍伐。清除后 5-10 年的 NO3 脉冲比 WTH 大。由于土壤中碱性阳离子、N 和 C 的消耗更大，WTH 导致地表水相对于 SOH 更大程度的酸化。使用林业作为气候缓解措施应考虑到对土壤和地表水质量的潜在影响。