Adaptive phenotypic plasticity and competitive ability deployed under a climate change scenario may promote the invasion of Poa annua in Antarctica

Abstract

Antarctica is one of the less prone envi-11 ronments for plant invasions, nevertheless a growing12 number of non-native species have been registered in13 the last decades with negative effects on native flora.14 Here we assessed adaptive phenotypic plasticity in15 three photoprotective traits (non-photochemical16 quenching, total soluble sugars, and de-epoxidation17 state of xanthophylls cycle), and fitness-related traits18 (maximum quantum yield, photosynthetic rate and19 total biomass) in the invasive species Poa annua and20 Deschampsia antarctica under current conditions of21 water availability and those projected by climate22 change models. In addition, two manipulative exper-23 iments in controlled and field conditions were con-24 ducted to evaluate the competitive ability and survivalof both species under current and climate change 25 conditions. Moreover, we performed an experiment 26 with different water availabilities to assess cell 27 damage as a potential mechanism involved in the 28 competitive ability deployed in both species. Finally, 29 was assessed the plasticity and biomass of both species 30 subject to factorial abiotic scenarios (water 9 tem- 31 perature, and water 9 nutrients) ranging from current 32 to climate change condition. Overall, results showed 33 that P. annua had greater phenotypic plasticity in 34 photoprotective strategies, higher performance, and 35 greater competitive ability and survival than D. 36 antarctica under current and climate change condi- 37 tions. Also, cell damage, assessed by lipid peroxida- 38 tion, was significantly greater in D. antarctica when 39 grown in presence of P. annua compared when grownalone. Finally, P. annua showed a greater plasticity42 and biomass than D. antarctica under the factorial43 abiotic scenarios, being more evident under a climate44 change scenario (i.e., higher soil moisture). Our study45 suggests that the high adaptive plasticity and compet-46 itive ability deployed by P. annua under current and47 climate change conditions allows it to cope with harsh48 abiotic conditions and could help explain its success-49 ful invasion in the Antarctica.