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The development of the annual population in Phragmites communis Trin.. 1970. Annals of Botany. 34, 571—91.


Each year, a young population of shoots of Phragmites communis Trin. shows a positively skew height/number curve. In a dominant stand the mode moves to the right during development, and the final growth curve is negatively skew. All fully developed shoots flower, but some buds are always formed too small to permit flowering; many shoots remain under-developed in unfavourable habitats; in bad weather potential flowering shoots may fail to develop through to flowering, and short inflorescences may fail to emerge and flower. The width of the emergent bud determines its potential number of nodes, and its potential for flowering.

The first cause of serious harm to young shoots is frost. Frost typically kills the early, potentially large, shoots, and gives a shorter and denser final population. Caterpillar damage comes rather later, and is more localized. With fewer replacement shoots, and less time in which these can mature, the final crop can be seriously reduced. Internal competition is serious only after the end of the emergence period, and as small and late-emerging shots are affected most, there is little effect on performance or flowering.