Environmental filtering, not local adaptation of established plants, determines the occurrence of seed- and bulbil-producing Poa alpina in a local flora

Abstract

Genetic variability among subspecies, ecotypes and populations is an important component of biodiversity, particularly when habitats are characterized by steep environmental gradients across short distances as in the landscape of the European Alps. In Poa alpina population differentiation is high due to polyploidy, facultative apomixis and the occurrence of seed-and bulbil-producing plants. We analysed microsatellite diversity of seed-and bulbil-producing populations from two nearby alpine grassland sites in the Swiss Alps and transplanted them reciprocally to test the hypothesis that established plants are locally adapted. The seed-and bulbil-producing populations differed molecularly strongly from each other despite their proximity. The seedproducing plants from the rich, calcareous grassland site performed well at both the home and the away site. Conversely, the bulbil-producing plants from the species-poor grassland had a comparatively low productivity at both sites, but performed better at the high-quality away site compared to its home site. Thus, local adaptation of established plants could not be confirmed by reciprocal transplantation. Results suggest that the distribution of seed-and bulbil-producing Poa alpina is a result of habitat quality, differences in plant performance, and the requirements for successful offspring recruitment. The prevailing occurrence of bulbil-producing plants at low productivity sites is probably due to different regeneration niches for seeds vs. bulbils, i.e. an advantage of bulbils at cold sites with poor soil and short growing seasons at this elevation.

Effect of nitrogen concentration and cotyledons on nitrogen preference in seedlings of Cedrus atlantica Manetti

“…This means that the gap between growth on NH 4 + and NO 3 depends on the cotyledons. The present results are consistent with those of Stöcklin and Armbruster (2016) which show that seed-producing individuals strongly differ molecularly from each other despite their proximity. Overall, it can be suggested that the preference of the nitrogen form by seedlings depends on the cotyledons which themselves depend on the availability and form of nitrogen in the rhizosphere of the mother plant during seed formation.…”

Variation of vegetative and floral traits in the alpine plant Solidago minuta: evidence for local optimum along an elevational gradient

“…Therefore, the elevational gradient has been considered as the most important factor in studies on phenotypic variation of plant species in mountains (e.g. Stöcklin et al 2009;Št'astná et al 2012;Kim and Donohue 2013;Scheepens and Stöcklin 2013;Gugger et al 2015;Hamann et al 2016;Stöcklin and Armbruster 2016;Sakurai and Takahashi 2016;Takahashi and Matsuki 2016). Plants can respond to elevational changes based on their morphological and physiological plasticity and through local adaptations (Hirano et al 2017).…”

Concepts in Alpine Plant Ecology

“…Substrate fertility may affect all climate response traits. For genotype tests, a most robust approach might be to sample replicated clonal fragments of different genets of the same species and replant them across the species’ home range [ 113 , 114 , 115 ]. Reciprocal transplantations of entire sods or monoliths can overcome the soil bias, but target species remain tied to the given neighborhood in the plant community.…”