Department of Bioscience, Aarhus University, Vejlsøvej 25, 8600, Silkeborg, Denmark.
Naturstyrelsen-Himmerland, Møldrupvej 26, 9520, Skørping, Denmark.
Ambio. 2020 Jan;49(1):324-336. doi: 10.1007/s13280-019-01181-2. Epub 2019 Apr 16.
Wetland restoration is considered an effective mitigation method for decreasing nitrogen (N) losses from agricultural land. However, when former cropland becomes rewetted, there is a risk that phosphorus (P) accumulated in soils will be released downstream. Here, we evaluate N and P retention in eight restored wetlands in Denmark monitored for 1 year using a mass balance approach. The wetlands represented different types, for instance, lakes and wet meadows, and ages (3-13 years). We also show the results from a long-term monitoring station established in 1973, located downstream a lake that was re-established in 2006. All restored wetlands removed total N (42-305 kg N ha year), while some wetlands acted as source of total P and others as a sink (- 2.8 to 10 kg P ha year). Our study confirms that restored wetlands are effective at removing N, whereas P can be released for several years after restoration.
湿地恢复被认为是减少农业用地氮（N）损失的一种有效缓解方法。然而，当以前的耕地重新湿润时，土壤中积累的磷（P）有可能被释放到下游。在这里，我们使用质量平衡法评估了丹麦的 8 个湿地恢复项目，这些湿地已被监测了 1 年。这些湿地代表了不同的类型，例如湖泊和湿地草甸，以及不同的年龄（3-13 年）。我们还展示了 1973 年建立的长期监测站的结果，该监测站位于 2006 年重建的湖泊下游。所有恢复的湿地都去除了总氮（42-305kgNha 年），而一些湿地是总磷的来源，而其他湿地则是总磷的汇（-2.8 至 10kgPha 年）。我们的研究证实，恢复的湿地在去除 N 方面非常有效，而 P 可能在恢复后的几年内被释放。
