Growth and physiological characteristics of five island tree species with drought stress

To compare the drought-resistance of five island tree species,namely,Ilex integra,Machilus thunbergii,Cinnamomum japonicum var.chenii,Eurya emarginata,and Eurya japonica,an experiment was conducted using tree seedlings with different soil drought stress levels.Plant physiological responses to the drought stress were measured.Results showed that the root and shoot biomass decreased as drought increased,but the root-to-shoot ratios(R/S) increased first and then decreased.In addition,chlorophyll content(Chl) decreased as drought stress increased.With severe drought stress,the survival rate was C.japonicum var.chenii I.integra M.thunbergii = E.emarginata E.japonica.A subordinate function used to rank drought-resistance showed: C.japonicum var.chenii I.integra M.thunbergii E.japonica E.emarginata.