Data from: Effects of extreme temperatures on the growth and photosynthesis of invasive Bidens alba and its native congener B. biternata

Temperatures are expected to fluctuate widely under climate change but little is known about how extreme temperatures might affect the physiology and performance of invasive compared to native plant species. In this study, we evaluated the effects of high (40/35oC) and low (10/5oC) temperature regimes on the growth and photosynthesis of the invasive Asteraceae species Bidens alba and its native congener B. biternata using a growth chamber experiment. Results showed that invasive B. alba had significantly greater total biomass and relative growth rate, accompanied by higher net photosynthetic rate (Pn), than native B. biternata at both low and high temperature extremes. The reduction in Pn for B. alba was mainly caused by stomatal limitations, but for B. biternata it was caused by non-stomatal factors, indicating that greater damage to physiological processes may occur in native B. biternata under both low and high temperature stress. Higher cyclic electron flow around photosystem I in invasive B. alba than in native B. biternata under extreme temperatures might alleviate the negative effect of temperature extremes to photosynthetic apparatus of invasive B. alba and thus promoted its photosynthetic efficiency. The invasive B. alba had both greater cold and heat tolerance than its native congener B. biternata, suggesting that the invader may outperform native species under future extreme temperature conditions.

气候变化背景下，气温预计将出现剧烈波动，但目前学界对极端温度如何影响外来入侵植物与本土植物的生理特性及生长表现的认知仍较为匮乏。本研究借助生长箱实验（growth chamber experiment），探究了极端高温（40/35℃）与极端低温（10/5℃）两种温度处理组合对入侵菊科（Asteraceae）植物白花鬼针草（Bidens alba）及其同属本土物种三叶鬼针草（Bidens biternata）的生长与光合特性的影响。实验结果表明，在两种极端温度条件下，入侵种白花鬼针草的总生物量、相对生长率均显著高于本土三叶鬼针草，同时其净光合速率（net photosynthetic rate，Pn）也更高。白花鬼针草的净光合速率下降主要由气孔限制（stomatal limitations）导致，而三叶鬼针草的光合速率下降则源于非气孔限制因素（non-stomatal factors），这表明在高低温胁迫下，本土三叶鬼针草的生理过程可能受到更为严重的损伤。极端温度条件下，入侵种白花鬼针草的光系统I（photosystem I，PSI）周围循环电子流水平高于本土三叶鬼针草，这或许能够缓解极端温度对入侵种白花鬼针草光合机构（photosynthetic apparatus）的负面影响，进而提升其光合效率。相较于同属本土物种三叶鬼针草，入侵种白花鬼针草兼具更强的耐寒性与耐热性，这意味着在未来极端温度环境下，该入侵种的生长表现将优于本土植物。