The class Montio-Cardaminetea comprises vegetation developing in springs with cold and well oxygenated water. Cold water with low nutrient content reduces vascular plant productivity, while leading to increasing bryophyte cover. Enhanced input of nutrients can therefore quickly change the structure of spring vegetation to the benefit of vascular plants. With increasing distance from a spring, flow rates and oxygenation decrease and spring vegetation is replaced by other communities, typically mire and fen vegetation of the class Scheuchzerio palustris-Caricetea nigrae. Spring vegetation occurs across a broad altitudinal range from lowlands to the subalpine belt, both in open places and under forest canopies.