De ecologie van het Groot boomglanswier [Tolypella prolifera (Ziz ex A. Braun) Leonhardi], een zeldzame cultuurvolger

Tolypella prolifera is a rare stonewort-species. Its distribution is centred in the Netherlands. Recent investigations in the province of Zuid-Holland show that it is less rare than was previously known. It is usually found in narrow, frequently cleaned ditches on clay soils, growing in shallow water with comparatively low amounts of potassium and phosphate. A frequent and thorough cleaning of the ditches by which all vegetation and organic matter is removed, is important for its survival. Tolypella prolifera then colonizes the barren clay soil.