From diaspore germination to climatic niche: Does microhabitat regulate the geographic distribution of peatland plants?

Hollow species exhibited higher germination and broader regeneration niches following dormancy release. Their strict reliance on overwintering cues aligns with a risk-avoiding “best-bet” strategy, concentrating mass germination during continuous, stable moisture to maximize recruitment. Conversely, hummock species—facing higher evaporation and moisture fluctuations—employed a risk-minimizing conservative strategy.

Higher germination thresholds and stringent responses to external cues prevented recruitment during unstable wet windows, mitigating drought mortality risks. Unexpectedly, local microhabitat type did not significantly constrain species’ macro-geographic ranges or climatic niche medians. Instead, macroclimatic adaptation diverged fundamentally between taxa.

Tracheophyte climatic optima were predicted by niche breadth, reflecting broad tolerance to seasonal hydrological extremes. In contrast, bryophyte climatic medians were strictly constrained by niche symmetry, highlighting a reliance on distributional stability. We conclude that peatland microhabitats do not directly dictate macro-distributions but act as strong environmental filters during early regeneration in plants.