High species turnover and low intraspecific trait variation in endemic and non-endemic plant species assemblages on an oceanic island

Hanz, Dagmar Martina; Beloiu, Mirela; Wipfler, Raja; Beierkuhnlein, Carl; Field, Richard; Jentsch, Anke; Vetaas, Ole Reidar; Irl, Severin David Howard

Abstract

Questions: Both species turnover and intraspecific trait variation can affect plant assemblage dynamics along environmental gradients. Here, we asked how community assemblage patterns in relation to species turnover and intraspecific variation differ between endemic and non-endemic species. We hypothesized that endemic species show lower intraspecific variation than non-endemic species because they tend to have high rates of in situ speciation, whereas non-endemic species are expected to have a larger gene pool and higher phenotypic plasticity. Location: La Palma, Canary Islands. Methods: We established 44 sampling sites along a directional gradient of precipitation, heat load, soil nitrogen, phosphorus and pH. Along this gradient, we estimated species abundances and measured three traits (plant height, leaf area and leaf thickness) on perennial endemic and non-endemic plant species. In total, we recorded traits for 1,223 plant individuals of 43 species. Subsequently, we calculated community-weighted mean traits to measure the relative contribution of species turnover, intraspecific variation and their covariation along the analysed gradient. Results: The contribution of intraspecific variation to total variation was similar in endemic and non-endemic assemblages. For plant height, intraspecific variation explained roughly as much variation as species turnover. For leaf area and leaf thickness, intraspecific variation explained almost no variation. Species turnover effects mainly drove trait responses along the environmental gradient, but intraspecific variation was important for responses in leaf area to precipitation. Conclusions: Despite their distinct evolutionary history, endemic and non-endemic plant assemblages show similar patterns in species turnover and intraspecific variation. Our results indicate that species turnover is the main component of trait variation in the underlying study system. However, intraspecific variation can increase individual species’ fitness in response to precipitation. Overall, our study challenges the theory that intraspecific trait variation is more important for the establishment of non-endemic species compared with endemic species.

Citation

Hanz, D. M., Beloiu, M., Wipfler, R., Beierkuhnlein, C., Field, R., Jentsch, A., …Irl, S. D. H. (2022). High species turnover and low intraspecific trait variation in endemic and non-endemic plant species assemblages on an oceanic island. Journal of Vegetation Science, 33(1), Article e13120. https://doi.org/10.1111/jvs.13120

• Journal Article Type: Article
• Acceptance Date: Jan 25, 2022
• Online Publication Date: Feb 8, 2022
• Publication Date: Jan 1, 2022
• Deposit Date: Apr 17, 2022
• Publicly Available Date: Apr 21, 2022
• Journal: Journal of Vegetation Science
• Print ISSN: 1100-9233
• Electronic ISSN: 1654-1103
• Publisher: Wiley
• Peer Reviewed: Peer Reviewed
• Volume: 33
• Issue: 1
• Article Number: e13120
• DOI: https://doi.org/10.1111/jvs.13120
• Keywords: Plant Science; Ecology
• Public URL: https://nottingham-repository.worktribe.com/output/7511525
• Publisher URL: https://onlinelibrary.wiley.com/doi/10.1111/jvs.13120