Data analysis

We performed analyses using GLMMs with sampling shrubs within plot and plots within zone as random variables (sampling shrubs were nested in plot; plots were nested in zone; n = 10 shrubs/plot) to examine the differences of number of flowers, number of mature pods, and seed number per pod among climate zones and across years (2012 and 2013). We performed analyses using LMMs with plots within zone as random variables (plots were nested in zone; n = 4 plots/zone) to examine the differences of flower biomass, fruit set, seed set, sexual allocation, and sexual allocation efficiency among climate zones and across years (2012 and 2013). We conducted correlation analyses between sexual reproduction indexes and aridity index (AI), flower number and flower biomass, fruit set and flower biomass, seed number per pod and flower biomass, seed set and flower biomass. All data analyses were performed with SPSS 21.0 (SPSS Inc).