Department of Civil and Environmental Engineering, Syracuse University, Syracuse, New York 13244, USA.
Environ Sci Technol. 2010 Jan 15;44(2):720-6. doi: 10.1021/es900890t.
Changes in climate and atmospheric deposition of base cations can alter the ionic composition of soil and surface waters, and therefore affect the structure and function of sensitive ecosystems. However, these drivers are not generally explicitly considered in the calculation of critical loads or dynamic critical loads to evaluate the recovery of ecosystems from elevated acidic deposition. Here we explore the importance of accounting for these changes in calculating dynamic critical loads for ecosystems. We developed three-dimensional dynamic critical load surfaces as a function of nitrate, sulfur, and base cation deposition under current and future climate change scenarios for the Hubbard Brook Experimental Forest, New Hampshire. This case study indicates that dynamic critical loads for nitrate and sulfur will be lower under conditions of potential climate change or decreases in base cation deposition. This analysis suggests that greater emission controls may be needed to protect sensitive forest ecosystems from acidic deposition under a future climate change or conditions of lower atmospheric deposition of base cations, particularly for watersheds experiencing elevated leaching losses of nitrate. This study should facilitate more informed policy decisions on emission control strategies and assessments of ecosystem recovery.
气候变化和大气中基础阳离子的沉积会改变土壤和地表水的离子组成，从而影响敏感生态系统的结构和功能。然而，在计算关键负荷或动态关键负荷以评估生态系统从酸化沉降中恢复的情况时，这些驱动因素通常并未明确考虑。本文探讨了在计算生态系统的动态关键负荷时考虑这些变化的重要性。我们针对新罕布什尔州哈伯德布鲁克实验森林，开发了基于当前和未来气候变化情景下硝酸盐、硫和基础阳离子沉积的三维动态关键负荷曲面。本案例研究表明，在潜在气候变化或基础阳离子沉积减少的情况下，硝酸盐和硫的动态关键负荷将会降低。该分析表明，在未来气候变化或大气基础阳离子沉积减少的情况下，为了保护敏感的森林生态系统免受酸性沉降的影响，可能需要采取更严格的排放控制措施，尤其是对于那些硝酸盐淋溶损失较高的流域。本研究将有助于在排放控制策略和生态系统恢复评估方面做出更加明智的政策决策。
