The Alpine Germination Syndrome Differs Between Temperate and Mediterranean Habitats

Abstract

Aims

Recently, alpine communities have shown changes in plant composition, potentially influenced by alterations in their reproductive fitness. Understanding the environmental cues that stimulate germination is therefore important for forecasting future impacts. Although general germination patterns have been described in alpine plants, their ecological determinants can be highly species- and context-specific. Here, we ask whether germination responses to environmental cues differ across alpine habitats and related communities in a climatically heterogeneous region.

Location

Cantabrian mountains (north-western Spain).

Methods

We examined four germination cues in 56 species from contrasting Mediterranean and temperate alpine habitats. We subjected the seeds to five months of cold stratification, mimicking snow-like conditions and recorded their germination. Using the remaining non-germinated seeds, we tested the effects of water limitation, darkness and constant temperatures on final germination compared to control conditions.

Results

Seed germination responses to cold stratification differed between habitats, with species from the Mediterranean habitat exhibiting significantly higher germination during stratification than those from the temperate habitat. Species from both habitats responded similarly to the other treatments: lack of water and light hindered germination.

Conclusions

Our results open the door to new germination strategies linked to multiple climatic variations occurring in alpine habitats worldwide. Although germination requirements are species-specific, they are also modulated by macro- and microclimatic conditions, determining climate-driven shifts in community composition. In warmer conditions with reduced snow cover, species that require short periods of cold stratification and can tolerate limited water availability are likely to be favoured.