Potential Impacts of Climate Warming on Distribution of Euptelea pleiospermum along Altitude:An Experimental Simulation

Climate change has already triggered species distribution shifts along the elevation gradient in many mountainous regions.Seed germination and seedling survival of Euptelea pleiospermum with different seed sources were examined under different elevations,aspects,in the forest or in the gap,and in spring or winter.The results showed that gaps were necessary for seedling survival and establishment.Furthermore,seed germination rate and seedling survival rate were not significantly different between the population at higher elevations(2090 m and 2350 m)and population from intermediate elevation(1600 m),but populations at 2220 m were lower.Seed germination rate and seedling survival of the population at lower elevations(900 m and 750 m)were lower than at the intermediate elevations,but at 620 m were as high as intermediate elevation.In addition,seed sources and aspect had no significant effect on seed germination and seedling survival rate.Cold stratification at high altitude had negative influences on seed germination and seedling survival.These ndings suggest that E.pleiospermum has the potential to move to higher elevation.Furthermore,forest gaps,which are not frequent,are necessary for seedling survival and establishment,indicating the limited population shift of E.pleiospermum to higher elevations.Finally,populations in lower elevations will be vulnerable to future climate change due to poor seedling recruitment,which may be mediated by some scattered suitable habitats.