Shoot height and density in Phragmites stands. 1971. Hydrobiolica. 12, 1139.
Primary production in Phragmites depends on shoot size and density. Once a bud is formed it can become narrower but not wider, and width at emergence is correlated with final height. Hence shoot height is controlled by factors influencing bud width and bud narrowing. Important external factors include nutrient and water regimes, litter, temperature, competition, etc. and internal ones include season and level of bud development. In autumn, bud formation is mainly controlled by long-term factors, while in spring it is much influenced by environmental fluctuations, particularly in temperature. In different conditions shoot, height and density are correlated, are inversely correlated, and vary independently. Production is determined mainly by factors acting on bud formation and bud growth below soil level.