low moor

...fens are broadly divided into mineralotrophic (eutrophic) fens, which are recharged by water that is rich in nutrients and not very acidic, and ombrotrophic (oligotrophic) fens, which are recharged only by rainwater and are acidic with few nutrients. Those in between are called mesotrophic fens. The terms low moor, middle moor, and high moor, which are terms derived from the relationship with groundwater levels, are commonly used to refer to oligotrophic, mesotrophic, and eutrophic fens, respectively.
[Wetland succession]
Peat bogs are formed when lakes and marshes turn into land, or when grasslands or forests turn into marshes due to poor drainage or spring water. They usually progress from swamps to low marshes and then to high marshes.

*Some of the terminology that refers to "low moor" is listed below.

Source | Heibonsha World Encyclopedia 2nd Edition | Information

…栄養物質に富み酸性度も高くない水に涵養される鉱物質栄養性(富栄養性)湿原fenと，涵養水が雨水に限られ，栄養物質が少なく酸性の水に涵養される降水栄養性(貧栄養性)湿原bogとに大別され，中間のものを中栄養性湿原という。地下水位との関係でできた語で，よく用いられている低層湿原low moor，中間湿原middle moor，高層湿原high moorという呼び方は，それぞれ貧･中･富栄養性湿原の意味で使われている。
［湿原の遷移］
　泥炭湿原のでき方には，湖沼の陸化による場合と，草原や森林の排水不良や湧水での沼沢化による場合とがあり，沼沢湿原，低層湿原，高層湿原へと進行するのが普通である。…

※「low moor」について言及している用語解説の一部を掲載しています。

出典｜株式会社平凡社世界大百科事典 第２版について | 情報