Functional responses to climate change may increase invasive potential of Carpobrotus edulis

• Published in: American journal of botany Vol. 108; no. 10; pp. 1902 - 1916
• Main Authors: G. Campoy, Josefina, Lema, Margarita, Fenollosa, Erola, Munné‐Bosch, Sergi, Retuerto, Rubén
• Format: Journal Article
• Language: English
• Published: Columbus Botanical Society of America, Inc 01.10.2021
• Subjects: Aizoaceae; Biodiversity; biomass allocation patterns; Carpobrotus edulis; Chlorophyll; Climate change; Climatic conditions; ecophysiology; Environmental changes; Evolution & development; evolutionary change; Factorial experiments; Genotypes; global warming; Growth rate; ice plant; Introduced species; Invasive plants; Invasive species; Invasiveness; isotope composition; Lipid peroxidation; Lipids; Peroxidation; Photochemicals; photoprotection; pigment contents; Populations; Rainfall; Rainfall levels; Survival; Temperature effects; Water use; Water use efficiency; Xanthophylls; Iberian Peninsula
• ISSN: 0002-9122; 1537-2197
• DOI: 10.1002/ajb2.1745

Premise Biological invasions and climate change are major threats to biodiversity. It is therefore important to anticipate how the climate changes projected for Southern Europe would affect the ecophysiological performance of the invasive South African plant, Carpobrotus edulis (ice plant or sour fig), and its capacity to undergo rapid adaptive evolution. Methods We manipulated the climate conditions in a field plot located on the island of Sálvora (northwest of the Iberian Peninsula) to establish a full factorial experiment with C. edulis plants transplanted from four native (southern African) and four invasive (northwestern Iberian Peninsula) populations. Throughout 14 months we measured growth and functional traits of this species under two temperatures (control vs. increased), and two rainfall levels (control vs. reduced). Results Temperature increased photochemical efficiency and relative growth rate of C. edulis. Rainfall modulated some of the effects of temperature on C and N isotopic composition, and pigment contents. Invasive populations showed lower root mass allocation and higher survival rates, as well as increased water use efficiency, lipid peroxidation, chlorophyll, and xanthophyll cycle pigment contents than native populations. Conclusions The increased growth and physiological performances observed under our experimental conditions suggest that the expected climate changes would further promote the invasion of C. edulis. Differences between native and invasive genotypes in survival and functional traits revealed that populations have diverged during the process of invasion, what gives support to the invasiveness hypothesis. Our findings highlight the importance of analyzing intraspecific variability in functional responses to better predict how invasive species will respond to environmental changes.