Climate warming could increase seed longevity of alpine snowbed plants
2015
Bernareggi, Giulietta | Carbognani, Michele | Petraglia, Alessandro | Mondoni, Andrea
Under climate change, regeneration from seeds is becoming increasingly important for species persistence, migration and conservation, especially in high-elevation environments. In this regard, the ability of seeds to remain viable for a long time is a crucial prerequisite for seed persistence in the soil and in germplasm banks. However, little is known about the effects of climate warming on seed longevity of alpine plants. Here, we analysed the effects of a moderately warmer parental growth environment generated by open top chambers on subsequent seed longevity of four alpine snowbed species. Seeds from plants exposed to natural and warmed climate during the growing season were subjected to laboratory-controlled accelerated ageing and then regularly sampled for germination tests. Initial viability (Ki), deterioration rate (σ ⁻¹) and time taken for viability to fall to 50 % (p ₅₀) were estimated using probit analysis. Across species and treatments, p ₅₀ varied from 4.9 to 23.1 days. Seeds produced by plants exposed to warmer temperatures were significantly longer lived than those from plants at natural conditions. Under warming, the seed progeny showed either a higher Ki or a slower σ ⁻¹ . Under moderate climate warming (about + 2 K), alpine snowbed species produced seeds with an extended resistance to heat stress indicating an effective rapid response to the new environment. Such plastic response may play a key role for survival and persistence of alpine snowbed species facing climate change and may also have important implications for ex situ conservation.
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