Phenology and reproduction of Poa alpina (2010-2011)

Phenology and reproduction of Poa alpina (2010-2011)

Poa alpina L. (Poaceae) is a widespread species in the subalpine and alpine zone of the European Alps, where it occurs mainly in moist, nutrient-rich pastures and meadows. As a pioneer species, it colonizes rocky sites and scree slopes on calcareous and siliceous bedrock, and in glacier forelands, it occurs as a ubiquitous species.
In grasslands, the perennial species can be found mainly with seminiferous inflorescences (i.e. producing seeds, P. alpina var. seminifera), but the proportion of individuals with pseudoviviparous inflorescences (i.e., producing plantlets instead of seeds on the mother plant, P. alpina var. vivipara) increases with altitude and severity of the environment.
Flowering and reproduction is controlled by environmental conditions, and it was suggested that pseudoviviparous inflorescences are a result of marginal or incomplete floral induction. As environmental conditions may vary substantially between years, the reproduction mode of Poa alpina may switch between seminiferous and pseudoviviparous inflorescences depending on the annual conditions. During the last years indications accumulated that the mode of reproduction is largely predetermined. Following this hypothesis, a switch of the reproduction mode should be a rare event.

Research Questions

  • How does the phenology differ along an altitudinal gradient and between successional stages?
  • Is the reproduction mode (seeds vs. plantlets) governed by habitat conditions or is it predetermined by the mother plant?
  • What is the influence of both environmental conditions and reproduction mode on the reproductive investment in Poa alpina?

Funding
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Personnel involved
Vera Margreiter (Master Thesis)
Erich Schwienbacher
Brigitta Erschbamer

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