Effects of simulated climate change on soil characteristics under Carpobrotus edulis invasion in a coastal backdune

Abstract

Background and aims: Along coastal habitats worldwide, Carpobrotus edulis is a highly invasive and detrimental species, that acts as an ecosystem engineer by modifying many soil properties for its own benefit. However, the combined effects of C. edulis and climate change on soil characteristics remain largely unknown. Methods: To address this knowledge gap, we set up a factorial field experiment with five treatments and eight replicates per treatment: natural vegetation as an uninvaded control under current climate conditions, C. edulis under current climate conditions, and C. edulis subjected to increased temperature (+ 2 ºC), decreased rainfall (- 33%), and both factors combined (+ 2 ºC and - 33% rainfall). The soil 0–5 and 5–10 cm layers were sampled after 14 months and analysed for 21 properties. Results: Although the effect of depth on soil characteristics was greater in most cases, the treatments significantly affected soil pHKCl, electrical conductivity, organic δ13C, NH4+-N, NO3−-N and available Al, Ca, Cu, Fe, Mg, Mn, P, and Zn. The discriminant analyses clearly differentiated the invaded from the uninvaded soils, reinforcing the view of C. edulis as an ecosystem engineer and highlighting the significant role of the species in shaping ecosystem dynamics. Besides, the analyses indicated that decreased precipitation had a greater impact on invaded soils than increased temperature, and suggested a synergistic effect of both climatic treatments. Conclusion: These findings underline the complex interactions between invasive species and climate change, highlighting the need for specific management strategies to mitigate C. edulis impacts on soil health and ecosystem integrity.

Open Access funding provided thanks to the CRUE-CSIC agreement with Springer Nature. The study was funded by the Spanish Ministry of Economy and Competitiveness and the European Regional Development Fund (ERDF) (grants Ref. CGL2013\u201048885\u2010C2\u20102\u2010R and Ref. CGL2017\u201087294\u2010C3\u20101\u2010P). The participation of Cristina Vieites-Blanco was supported by a pre-doctoral fellowship by Xunta de Galicia and by the European Union\u2019s Horizon 2020 research and innovation program under the Marie Sk\u0142odowska-Curie grant agreement No 101034288. Josefina Gonz\u00E1lez Campoy was supported by a postdoctoral research grant from the Autonomous Government of Galicia (Spain). The isotopic ratio mass spectrometer was partly financed by the European Regional Development Fund (EU).