The Leutstettener Moos is a nature reserve in the Leutstetten district of the city of Starnberg in Upper Bavaria. It is a fen on a silted part of Lake Starnberg; it is located on its only outflow, the Würm, north of the lake shore. It ends in the north at the double terminal moraine, the breakthrough of which marks the beginning of the Mühltal. The 180.00 hectare area was declared a nature reserve by decree of November 5, 1984
The Leutstettener Moos lies in a hollow that runs roughly from south to north around the course of the Würm. It emerged in the Würm Ice Age as the northernmost part of the central tongue basin of the Isar-Loisach Glacier, the southern portion of which is Lake Starnberg. The glacier tongue deposited lake clay that sealed the moraine so that the meltwater formed a lake. In the bed of the Maisinger Bach and the Lüß-Bach, rock was brought into the lake from the flanks.[2] The resulting rock deposits dammed up the northern part of the lake more than the rest, so that a fen was created in the water body, which only flowed slowly, which was overgrown in places by a transitional bog and, on the eastern edge, parts of a rainfed bog. A peat layer of up to 1.5 m can be detected there. The Würm River expands several times into small open areas of water. An oxbow lake, the Alte Würm, was separated by an approximately 500 m long breakthrough before it was declared a protected area.
The Würm in the Leutstettener Moos
The protected area almost exclusively includes the lowlands and, with parts of the castle wood (towards Leutstetten Castle of the Wittelsbachers) in the west, a small hill that was formed as a ground moraine of the Würm Age glacier. The fen is largely in a near-natural condition. Exceptions are small areas of forest in the northern part, some of which have been reforested with non-native conifers. The parts of the Lower Castle Forest in the west of the NSG that belong to the protected area are a mixed forest closer to the potentially natural vegetation. In the core area there is a natural touch of birch and pine in some areas. The forest to the east has very different characters depending on the terrain profile. In the southeast, around the Röhrlbach, which flows into the Würm in the NSG, there is a quarry forest whose characteristic species are alders. In more open places it is interspersed with Großseggenried. It is partially flooded during floods and largely flooded when the water level is extreme. To the north, moss biotopes stretch for at least a kilometer to the wild moss through the forest, which is predominantly afforested with spruce.