Forest status is crucial for catchment hydrology and water quality but is increasingly disturbed by human activities and climatic factors. Therefore, it is urgently necessary to develop water quality models that can adapt to these changes. This study used a new dynamic Hydrological Predictions for the Environment (HYPE) model to assess the effect of rapid and continuous forest changes on catchment hydrology and nitrogen export. The modified HYPE model was implemented for the 25 years period in the Große Ohe catchment in Germany, which has experienced severe forest dieback and recovery. Due to the stochastic nature of infestation events, data covering the entire process of forest change are rare. The modified HYPE model performed well at different scales for discharge and dissolved inorganic nitrogen (DIN) export. It was able to (a) capture the timing of peak flows and the seasonal DIN concentration dynamics and (b) reflect the initial increase and subsequent decrease trend in discharge and DIN export in accordance with forest dieback and regeneration. The increase in nitrogen export after forest dieback primarily resulted from reduced forest uptake and increased soil nitrogen availability from tree residues. The difference in runoff and nitrogen export increment with or without regeneration highlights the importance of forest regeneration in restoring catchment hydrology and water quality. Additionally, a decrease in DIN export after residue removal implies the impact of sound post-disturbance management strategies. The dynamic modeling under changing catchment forests can enhance the analysis of catchment water quality and effectively support forest management.

中文翻译：

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使用新的动态水质模型，森林枯萎对水文和氮输出的影响


森林状况对流域水文和水质至关重要，但越来越受到人类活动和气候因素的干扰。因此，迫切需要开发能够适应这些变化的水质模型。本研究使用一种新的动态环境水文预测 （HYPE） 模型来评估快速和连续的森林变化对流域水文和氮输出的影响。修改后的 HYPE 模型在德国的 Große Ohe 流域实施了 25 年，该流域经历了严重的森林枯萎和恢复。由于侵扰事件的随机性，涵盖森林变化整个过程的数据很少。改进的 HYPE 模型在不同尺度上对排放和溶解无机氮 （DIN） 输出表现良好。它能够 （a） 捕捉峰值流量的时间和季节性 DIN 浓度动态，以及 （b） 根据森林枯萎和再生，反映排放和 DIN 出口的初始增加和随后的减少趋势。森林枯萎后氮输出的增加主要是由于森林吸收减少和树木残留物对土壤氮的可用性增加。有或没有再生的径流和氮输出增量的差异突出了森林再生在恢复流域水文和水质方面的重要性。此外，残留物去除后 DIN 输出的减少意味着合理的干扰后管理策略的影响。变化流域森林下的动态建模可以增强流域水质分析，并有效支持森林管理。