Fertiliser use in agriculture increases the non-point pollution of waters with nitrogen (N) and phosphorus (P). Wetland buffer zones (WBZs) are wetland ecosystems between agricultural lands and water bodies that protect surface waters from non-point source pollution. We assessed how vegetation harvesting within WBZs impacts their N and P removal efficiency, nutrient uptake by plants and their biomass quality. We surveyed vegetation of a spontaneously rewetted fen along a small river in Poland, and analysed plant biomass, its nutrient contents and nutrient-leaching potential and the water chemistry. Total N removal reached 34–92% and total P removal 17–63%. N removal was positively related to the initial N concentration, regardless of mowing status. We found a high N removal efficiency (92%) in the harvested site. Vegetation of mown sites differed from that of unmown sites by a higher water-leached carbon and P contents in the biomass. We found that vegetation harvesting may stimulate the overall N removal, but may increase potential biomass decomposability, which eases the recycling of plant-incorporated nutrients back to WBZ. Thus, mowing should always be followed by the removal of biomass. Neglecting already mown WBZs may temporarily lower their nutrient removal efficiency due to potentially faster decomposition of plant biomass.

中文翻译：

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植被采伐对湿地缓冲区养分去除和植物生物量质量的影响

农业中的肥料使用增加了氮（N）和磷（P）对水域的面源污染。湿地缓冲区 (WBZ) 是农业用地和水体之间的湿地生态系统，可保护地表水免受非点源污染。我们评估了 WBZ 内的植被收获如何影响它们的 N 和 P 去除效率、植物的养分吸收及其生物量质量。我们调查了波兰一条小河沿岸自发再润湿的沼泽植被，并分析了植物生物量、其营养成分和营养浸出潜力以及水化学。总氮去除率达到 34-92%，总磷去除率达到 17-63%。无论割草状态如何，氮去除量与初始氮浓度呈正相关。我们发现收获地点的 N 去除效率很高 (92%)。已修剪场地的植被与未修剪场地的植被不同，在于生物质中更高的水浸出碳和磷含量。我们发现植被收获可能会刺激整体的 N 去除，但可能会增加潜在的生物量可分解性，这有助于植物吸收的养分循环回 WBZ。因此，割草之后应始终去除生物质。由于植物生物量分解速度可能更快，忽略已经修剪过的 WBZ 可能会暂时降低它们的养分去除效率。割草之后应始终去除生物质。由于植物生物量分解速度可能更快，忽略已经修剪过的 WBZ 可能会暂时降低它们的养分去除效率。割草之后应始终去除生物质。由于植物生物量分解速度可能更快，忽略已经修剪过的 WBZ 可能会暂时降低它们的养分去除效率。