Distribution of plant communities in relation to hydrological condition of Furen mire, northern Japan.

我们研究了混合沼泽的建立机制，这是一个矿养沼泽与许多富营养化的驼峰泥炭藓fuscum通过检查植物群落的分布与水文和化学变量的关系。研究区域为宽约1400 m的湿地，分布在一个从丘陵边缘向下延伸至辅仁河的极缓坡上。混合沼泽与山体边缘相邻，宽度约200 m，矿养沼泽分布在山体下部，水量平衡分析表明，每次降雨后，混合沼泽地表水开始流出，但短期内地表水停止流出，维持稳定水位。当水位上升到高于湿地表面2 cm以上时，各浅池和孤立池中的沃茨连成一体，沿沿着向下流动，在1998 ~ 1999年水位最高时，指示水化学、高EC和大量矿物质和营养物质的洪水河水流入下部沼泽区。然而，混合沼泽区没有洪水中的矿物质和营养物质。而混合沼泽中的水也表现出较高的EC值，这是因为富含矿物质的水通过径流机制从山上的牧场进入混合沼泽。结果表明，湿地两端EC值均高于中部，混合沼泽中的丘丘比湿地表面高50 cm以上，下垫面稳定，不会将矿物质和营养物质带入丘中上部。因此，生长在富营养化水体上的丘状体可以保持恒定水位下的富营养化状态。

We studied the mechanism of the establishment of the mixed mire, which is a minerotrophic fen with many ombrotrophic hummocks of Sphagnum fuscum by examining the distribution of plant communities in relation of hydrological and chemical variables. The area we studied was 1400 m wide wetland distributed on a extremely gentle slope going downward from a hill margin to Furen river. The mixed mire was adjacent to a margin of the hill with 200 m wide, and the minetrophic fen was distributed in a lower part.Analysis of water budget showed that surface water in the mixed mire began to flow out just after each rainfall whereas surface water flowing stopped within a short period, maintaining in a stable water level. When the water level increases to more than 2 cm above a wetland surface, waters in shallow and isolated pools become to connect into one and flow downward along a gentle slope.At the time of the highest water level within 1998 to 1999, the flooding river-water indicating water chemistries, high EC and much minerals and nutrients, flowed into the fen area of the lower part. The area of the mixed mire, however, was free from the supply of minerals and nutrients in flooding water. Water in the mixed mire, however, also showed high EC value because mineral-rich water was supplied from pasturage lands on the hill into the mixed mire through the run-off mechanism before mentioned. As a result, both ends of the wetland area keep higher EC values than middle part.Since hummocks in the mixed mire are 50 cm or more higher than the wetland surface, an underlying stable water table does not carry minerals and nutrients into middle to upper part of hummocks. Accordingly, hummocks growing on the minerotrophic water can keep the ombrotrophic condition as it is under the constant water level.