The effect of harsh abiotic conditions on the diversity of serpentine plant communities on Lesbos, an eastern Mediterranean island

Abstract

Background: Diversity patterns of plant communities are related to the environment, including productivity and patchiness of habitat.

Aims: To determine differences in diversity patterns between serpentine and non-serpentine communities.

Methods: A two-year study was conducted in native eastern Mediterranean grasslands. For each year 40 0.25 m² plots were sampled across four pairs of sites, each of which contained a serpentine and an adjacent non-serpentine plant community. Alpha and beta diversity (variation in species composition among plots within localities), species composition and biomass production were determined. Total soil elemental concentrations and pH were also measured.

Results: Serpentine habitats were shown to support a lower alpha diversity relative to non-serpentine habitatas on a per plot basis. Differences in alpha diversity between the two substrates were associated with variation in soil chemistry rather than above-ground biomass production. Serpentine habitats also exhibited lower beta diversity, which was unrelated to variation in biomass production. The two contrasting communities presented distinct species composition.

Conclusions: Differences in diversity patterns between serpentine and non-serpentine communities in the eastern Mediterranean are influenced by soil chemistry rather than biomass production.

Keywords:

• alpha diversity
• beta diversity
• floristic composition
• heavy metals
• productivity
• stress
• ultramafic soils

Acknowledgments

We would like to thank I. Bazos for species identification, Bernhard Schmid (University of Zurich) and S. Koukoulas for their advice on statistical analysis, and S. Harrison and four anonymous reviewers for their constructive comments on an earlier version of the manuscript. This research was co-financed by the European Union (European Social Fund) and national Greek funds through the Operational Program ‘Education and Lifelong Learning’ of the National Strategic Reference Framework (NSRF) – Research Funding Program: Heracleitus II. Investing in knowledge society through the European Social Fund.

Additional information

Notes on contributors

George C. Adamidis

George C. Adamidis is a Ph.D. candidate. His research is focused on the functions and factors shaping plant species diversity in stressful (serpentine) environments, and on understanding the mechanisms behind the processes of metal tolerance and hyper-accumulation in plants.

Elena Kazakou

Elena Kazakou is an assistant professor. Her main research focuses on analysing the ecological consequences of variability of plant functioning through the use of functional traits.

Alan J.M. Baker

Alan J.M. Baker is an honorary professor at the Universities of Melbourne, Queensland, and Sheffield. His life-time research has been focused on the ecophysiology and evolutionary biology of plant adaptation to metalliferous soils and the development of phytotechnologies for the clean-up and restoration of contaminated and mining lands.

Roger D. Reeves

Roger Reeves has recently retired after 41 years as a lecturer and professor in physical and analytical chemistry at Massey University. Since the 1970s he has held a major interest in soil–plant elemental relationships, particularly in the unusual accumulation of trace elements by plants in many types of metalliferous environments.

Panayiotis G. Dimitrakopoulos

Panayiotis G. Dimitrakopoulos is an associate professor of functional ecology. His research is focused on biodiversity effects in ecosystem processes in Mediterranean ecosystems, serpentine ecology, and on biodiversity conservation and planning.