Ecophysiology of the Sand Sedge, Carex arenaria L. I. Growth and dry matter distribution

The growth and the dry matter distribution of sand sedge plants were followed in time by means of an indirect estimation method. This method enabled us to calculate the time courses of both the growth of the whole plant, and the growth of the individual shoots from measurements of the shoot length, the number of leaves and the length and width of the leaf laminae only. The growth rate of each individual shoot decreases with time. In the primary shoots 1-7 the amounts of dry weight added during the experiment were equal to each other, indicating a higher growth rate for the younger shoots. A comparison of dry weight production and increase in dry weight of shoots gave the amount of dry matter import or export by those shoots. The dry matter production in the tip part of the rhizome (two shoots, a shoot bud, the rhizome parts and the roots attached to them) proved to be far too small to maintain the growth of the non-assimilating tissue in this part. There must be a considerable export from the older plant part towards the rhizome tip region. It should be mentioned that the results presented here are similar to those obtained from 14C studies. Because of its simplicity the method we used would be very suitable for use in field studies.