Germination niche breadth and potential response to climate change differ among three North American perennials

摘要: Responses of species to environmental change are largely dependent on their niche breadth. To investigate the relationship between germination breadth and sensitivity climate change, we selected three North American perennials: Physalis longifolia, Asclepias syriaca Penstemon digitalis. Dormancy loss requirements were determined for seeds from populations along a Midwest US latitudinal gradient. Fresh incubated at 1, 5, 9, 15/6, 20/10, 25/15 30/15°C, cold stratified 5 9°C 4–12 weeks 30/15°C. Germination (Levins’ Bn) was calculated final proportion. In addition, sequence temperatures evaluated effect future warming phenology. differed significantly among collection latitudes (P < 0.001), but variation did not have pattern. Niche widest narrowest ≤ 0.05), with implications shifted autumn under in northern regions, earlier spring regardless region. Due limited stratification requirements, resulting breadth, initially predicted be most at-risk, as would fall outside its envelope. However, wide breadths (Physalis Asclepias) may more vulnerable due maladaptive shifts