Factors affecting the distribution and abundance of orchids in grasslands and herbaceous wetlands

Abstract

Grasslands, wet meadows, fens, bogs, and marshes represent important ecosystems that host many orchid species. However, research on the joint effect of the multi-scalar abiotic drivers on orchid distribution and abundance in these habitats is limited. In this study, we investigated factors associated with the occurrence and abundance of 42 orchid taxa in grasslands and herbaceous wetlands of 29 mountains and the surrounding low altitude areas in western Serbia (eastern Dinaric Alps, southeastern Europe). Niche analysis of orchids was performed using outlying mean index analysis (OMI). In addition, we used similarity profile analysis (SIMPROF) to classify orchid taxa into ecological groups, multi response permutation procedure (MRPP) to analyse the differences in orchid composition between vegetation types, and indicator species analysis (ISA) to detect orchids with an affinity to a certain type of vegetation and geological bedrock. The most important gradients that separate orchids within the sampled environmental conditions were moisture, temperature, altitude and soil pH. Moreover, this study underlines the importance of certain vegetation types and geological bedrocks in determining the distribution and abundance of orchids. In total, eight ecological groups of orchids were distinguished. The results have shown that 11 orchid taxa are indicators of specific vegetation types, whereas 13 orchid taxa are indicators of specific bedrock types. The study area provides suitable conditions for survival of some rare and endemic orchid species that have southern limits of their distribution in this part of southeastern Europe. The study suggests that the joint effect of ecological factors, especially vegetation communities and bedrock types, is important to consider in the planning and management of orchid species conservation.

Keywords:

• ecology
• geological substrates
• grasslands
• herbaceous wetlands
• niche analysis
• Orchidaceae

Acknowledgements

The authors thank Tara National Park, Forest Estate ‘Golija’ Ivanjica, Citizens Association ‘Jadovnik’ and Goran Nikolić (Tourist Organization of Čačak) for hospitality and logistical field support. We are grateful to Dr Ljupko Rundić and the Department for Mineralogy, Crystallography, Petrology and Geochemistry (Faculty of Mining and Geology, University of Belgrade) for help in identification and classification of geological bedrock types. We also thank Dr Alessandro Chiarucci (University of Bologna) for valuable comments and suggestions on the manuscript. We are grateful to Dr Nadia Bystriakova, Dr Schatz Bertrand, and an anonymous reviewer, who provided valuable suggestions to improve the first version of this manuscript.

Disclosure statement

No potential conflict of interest was reported by the authors.

Supplemental data

Supplemental data for this article can be accessed here http://dx.doi.org/10.1080/14772000.2016.1151468.

Additional information

Funding

This work was supported by the Ministry of Education, Science and Technological Development of the Republic of Serbia under Grant number 173030.