Seasonal changes in the standing crop of two montane sedges

Aboveground green biomass of a montane pure stand of Carex rostrata varies from about 125 g/m2 (air-dry weight) at the end of November to about 640 g/m2 in early August. The maximum production rate of about 6 g/m2 per day occurs in May. For a nearby stand of Carex aquatilis with a prominent moss layer the aboveground green biomass of sedge material varies from about 40 g/m2 in February to about 380 g/m2 in mid-August. The maximum production rate for sedge material is about 4 g/m2 per day in July. Both species exhibit two main populations of shoots, one emerging in late summer and the other through winter and early spring. The winter and spring shoots of Carex rostrata flower and die after about 18 months, while the late summer shoots, which do not mature vegetatively until the following summer, have a life-span of about 2 years. The late summer shoots of Carex aquatilis mature vegetatively before winter, and flower and die within about 12 months; while the winter and spring shoots live through the next winter, and flower and die the following summer after a life-span of about 18 months.