‘Poor rich fen mosses’: atmospheric N-deposition and P-eutrophication in base-rich fens

摘要: Base-rich fens in the Netherlands are threatened by acidification and replacement of rich-fen bryophytes Sphagnum spp. Acidification is a natural process when input base-rich water reduced, probably accelerated high atmospheric deposition, leading to lower pH at similar calcium levels, increased capacity Sphagnum. However, may also be due eutrophication, especially with P, which leads shift stable states from Sphagnum-dominated fen. Under nutrient-poor conditions, Scorpidium scorpioides fen stabilized as long sufficient supplied. The species tolerant rainwater even counteract acidification. Its successor subnitens, however, intolerant groundwater has low capacity, can only become dominant after changes hydrology (local) accumulation rain water. nutrient-rich S. replaced Calliergonella cuspidata. In contrast scorpioides, this rainwater. Moreover, its squarrosum grows already well under conditions. High growth rates further lead rapid expansion species, fen, loss characteristic species. For conservation rich it thus very important keep habitat base-rich, but nutrient-poor.