『Abstract
　Late-successional forests in the upper Great Lakes region are susceptible to nitrogen (N) saturation and subsequent nitrate (NO3^-) leaching loss. Endemic wind disturbances (i.e., treefall gaps) alter tree uptake and soil N dynamics; and, gaps are particular susceptible to NO3^- leaching loss. Inorganic N was measured throughout two snow-free periods in throughfall, forest floor leachates,and mineral soil leachates in gaps (300-2,000 m², 6-9 years old), gap-edges, and closed forest plots in late-successional northern hardwood, hemlock, and northern hardwood -hemlock stands. Differences in forest water inorganic N among gaps, edges, and closed forest plots were consistent across these cover types: NO3^- inputs in throughfall were significantly greater in undisturbed forest plots compared with gaps and edges; forest floor leachate NO3^- was significantly greater in gaps compared to edges and closed forest plots; and soil leachate NO3^- was significantly greater in gaps compared to the closed forest. Significant differences in forest water ammonium and pH were not detected. Compared to suspected N-saturated forests with high soil NO3^- leaching, undisturbed forest plots in these late-successional forests are not losing NO3^- (net annual gain of 2.8 kg ha^-1) and are likely not N-saturated. Net annual NO3^- losses were observed in gaps (1.3 kg ha^-1) and gap-edges (0.2 kg ha^-1), but we suspect these N leaching losses are a result of decreased plant uptake and increased soil N mineralization associated with disturbance, and not N-saturation.

Keywords: Forest gap; Forest floor leachate; Nitrate; Soil leachate; Throughfall』

Introduction
Materials and methods
　Site description
　Forest water fluxes
　Drainage flux estimates with WATBAL
　Statistical analyses
Results and discussion
　Justification for examining treatment effects across cover types
　Forest water and N flux treatment effects across cover type
　Nitrate retention capacity of gaps, edges, and forests
Conclusion
Acknowledgements
References