Details

Autor(en) / Beteiligte

• Solveig Nachtigall
• Karsten Mohr
• Luise Giani

Titel

Water, soil and vegetation under the influence of high atmospheric nitrogen deposition in a cutover and rewetted raised bog in Northwest Germany

Ist Teil von

• Mires and peat, 2023-01, Vol.29 (7), p.1-16

Ort / Verlag

International Mire Conservation Group and International Peatland Society

Erscheinungsjahr

2023

Quelle

EZB Electronic Journals Library

Beschreibungen/Notizen

• Bogs located near agricultural areas often receive high atmospheric nitrogen (N) depositions, and this may result in an increased soil and water N pool and enhanced N supply for plants and microorganisms. The consequences are changes in plant species composition and diffuse emissions of N species from these bogs. However, research on the resilience of rewetted bogs to high atmospheric N inputs is still sparse. Our aim was to evaluate the influence of N depositions on a bog that was rewetted after peat extraction down to bare ‘black’ (highly decomposed) bog peat. We monitored dry (NH3) and wet (NH4+ and NO3-) deposition, and plant available N as NH4+ and NO3- in soil and water, over the course of one year. The amount of N stored in vegetation was also quantified. We detected a total N deposition of 32 kg ha-1 y-1 which by far exceeded the critical load (5–10 kg ha-1 y-1) for bogs, but there were no signs of deposition induced N increase in soil and bog water. Our findings suggest, rather, that levels of plant available N were crucially affected by mineralisation in areas with lower water table. Depending on the sampling station, the amount of N stored in the vegetation was 23 or 30 kg ha-1. Although it was likely that uptake by vegetation played a decisive role in buffering the high N depositions, it did not completely explain the whereabouts of excess N. Accordingly, other processes like peat growth, N removal by mowing or denitrification must have contributed to buffering N levels in soil and water.