The effects of spring versus summer heat events on two arid zone plant species under field conditions

This dataset contains raw data for Milner, K.V., French, K., Krix, D.W., Valenzuela, S.M., and Leigh. A. (2023) The effects of spring versus summer heat events on two arid zone plant species under field conditions. Plant Functional Biology.

We addressed the following questions: 1) Is a spring or summer heat stress event more detrimental to growth and fitness outcomes for desert plants? 2) How does nutrient availability influence downstream effects of heat stress? To address these questions we applied spring or summer heat stress to two Australian arid zone Solanum species grown under two nutrient treatments and followed plants through to fruiting. Briefly, plants exposed to a summer heat stress event faired more poorly than plants exposed to spring heat stress, however outcomes for reproductive fitness were species specific.

This experiment used a fixed, four-factor design, each factor with two levels. The heat stress event was the level of replication; therefore the sample size was four (except where specified). Visible damage and survival were analysed using binomial logistic regression. ANOVA with Type II sums of squares using ‘lm’ function was applied to all other variables (leaf temperature, damage to PSII, membrane stability, LMA, growth rate, flower and fruit number, stem to leaf, flower or fruit to aboveground biomass ratios, leaf protein). Transformations were made where required to meet assumptions of analyses. Models were simplified by removal of non-significant interactions using and AIC values using ‘drop1’ function of ‘car’ package. Where there were significant interactions, Tukey HSD in ‘emmeans’ package was applied.

For more information see Milner et al. (2023) and steps to reproduce.