Native Australian seedlings exhibit novel strategies to acclimate to repeated heatwave events

Heatwaves are becoming more intense and frequent. Plant photosystem thermal thresholds can vary with species, but also shift in response to environmental triggers. Both upper and lower thresholds can acclimate to repeated heatwaves through ecological stress memory, where prior exposure primes them for subsequent events. The extent to which acclimation to repeated heat stress events varies among environmental origin and/or species is unknown. Different acclimation strategies might reflect biome of origin, or may be species-specific. For 12 species from two contrasting biomes – extreme desert and benign coastal temperate – we investigated responses to two simulated heatwaves, via shifts in upper and lower critical temperatures of photosystem II, and the difference between these thresholds, thermal tolerance breadth (TTB).  Biome of origin had no effect on thermal tolerance. Observed differences among species following heat events suggested two possible acclimatory strategies. In some..., , ## Native Australian seedlings exhibit novel strategies to acclimate to repeated heatwave events Contains 15 files: (1) Analysis - R scripts required to replicate analysis and figures in the manuscript and supplementary material: DRYAD biome and species lmer models.R DRYAD Delta models.R DRYAD Figure 2.R DRYAD supp.R (2) Datasets (11 files total): dfcold.csv dfhot.csv dfTTB.csv For analysis of effect of treatment and time period on seedling tcrit_hot, tcrit_cold and thermal tolerance breadth Columns: * stage - the time period of when the measurement was taken; 1,2,3,4 * biome - desert (extreme), coastal temperate (benign) * species - Acacia longifolia, Acacia salicina, Acacia victoriae, Banksia integrifolia, Capparis mitchellii, Carex appressa, Casuarina pauper, Eucalyptus largiflorens, Flindersia maculosa, Lomandra longifolia, Melaleuca hypericifolia, Pittosporum undulatum * treatment - 0_HW, control; 1_HW, one heatwave; 2_HW, two heatwaves * block_rep - replicate; 1, 2, 3, 4, 5...,热浪正变得愈发强烈且频发。植物光系统（photosystem）的热阈值不仅因物种而异，还会随环境触发因素发生改变。其上下阈值均可通过生态胁迫记忆适应反复热浪胁迫——即前期的热暴露会为后续的热浪事件预先做好应对准备。目前尚不清楚，针对反复热胁迫的适应程度在不同环境起源的物种间存在多大差异。不同的适应策略可能反映物种的原生生物群系（biome）特征，也可能是物种特异性的。 本研究针对来自两类截然不同生物群系——极端荒漠与温和沿海温带——的12个物种，通过检测光系统II（photosystem II）上下临界温度的变化，以及二者之差即热耐受广度（thermal tolerance breadth, TTB），探究了它们对两次模拟热浪的响应。 原生生物群系对物种的热耐受能力并无影响。热浪事件后观测到的物种间差异提示了两种潜在的适应策略。部分……## 澳大利亚本土幼苗展现出适应反复热浪事件的新型策略 本数据集共包含15个文件： (1) 分析代码：用于复现论文正文及补充材料中的分析与图表的R脚本： DRYAD biome and species lmer models.R DRYAD Delta models.R DRYAD Figure 2.R DRYAD supp.R (2) 数据集（共11个文件）： dfcold.csv dfhot.csv dfTTB.csv 用于分析处理与测量时段对幼苗tcrit_hot、tcrit_cold及热耐受广度的影响 列信息如下： * stage：测量时段，取值为1、2、3、4 * biome：原生生物群系，分为荒漠（极端型）、沿海温带（温和型） * species：供试物种，具体包括Acacia longifolia、Acacia salicina、Acacia victoriae、Banksia integrifolia、Capparis mitchellii、Carex appressa、Casuarina pauper、Eucalyptus largiflorens、Flindersia maculosa、Lomandra longifolia、Melaleuca hypericifolia、Pittosporum undulatum * treatment：处理组，0_HW为对照组；1_HW为单次热浪处理组；2_HW为两次热浪处理组 * block_rep：生物学重复，取值为1、2、3、4、5……