Rewetting effects on nitrogen cycling and nutrient export from coastal peatlands to the Baltic Sea

作者：Anne Breznikar, Daniel Pönisch, Marvin Lorenz, Gerald Jurasinski, Gregor Rehder, Maren Voß · 发表于：Biogeochemistry · 年份：2024 · DOI：10.1007/s10533-024-01149-9 · 被引用次数：5 · 研究领域：Peatlands and Wetlands Ecology、Coastal wetland ecosystem dynamics、Soil and Water Nutrient Dynamics

Abstract Coastal nutrient loads from point sources such as rivers are mostly well-monitored. This is not the case for diffuse nutrient inputs from coastal catchments unconnected to rivers, despite the potential for high inputs due to intensive land use. The German Baltic Sea coastline consists of numerous peatlands that have been diked and drained. However, some of the dikes have been removed in order to re-establish the hydrological connection to the Baltic Sea, restore local biodiversity, and promote natural CO 2 uptake. Since these peatlands were used for agriculture, their rewetting may release accumulated nutrients, leading to nutrient export into the Baltic Sea and intensified coastal eutrophication. Data on these potential nutrient exports are mostly lacking. Therefore, this study investigated nutrient exports from two former agricultural, coastal peatlands: Drammendorfer Wiesen, rewetted in 2019, and Karrendorfer Wiesen, rewetted in 1993. Nutrients (NO 3 – , NO 2 – , NH 4 + , PO 4 3– ), nitrous oxide (N 2 O), particulate organic matter (POM, comprising POC and PON; δ 13 C-POC), chlorophyll- a, and nitrification rates were analyzed in surface water and porewater sampled weekly to monthly in 2019 and 2020 to compare the effects of different time scales after rewetting on nutrient cycling and potential exports. NH 4 + , NO 2 − , and PO 4 3− concentrations were higher in the porewater than in the overlying water at both sites, while nutrient concentrations were generally ...