Tiller demography of Festuca rubra in a mountain grassland: seasonal development, life span, and flowering

The paper reports on demography of individual tillers in seventeen selected tussocks of Festuca rubra subsp. rubra over four vegetation seasons in a managed species-poor Nardetalia grassland. Natality of tillers peaked once a year only in spring; there was no increase of natality after the summer clipping. Tiller mortality showed no pronounced seasonal variation. Though flowering invariably resulted in the tiller death, flowering accounted only for 13-15% of the overall tiller mortality. Flowering tillers were statistically bigger already in the previous year, though the strength and timing of this size difference differed between years. Lifespan of tillers varied strongly, from several weeks to several years. Tiller survivorship was roughly exponential.