Floristic, chorological and life-form patterns at the highest summits of Mt Olympus, Greece

ABSTRACT

High elevation habitats within the Mediterranean biome are expected to be disproportionally exposed to climate change impacts in comparison to the ecosystems of the lower and drier sites. The distribution and structure of alpine ecosystems greatly depend on temperature variables including growing season length. Tree-line shifts, structural change of alpine plant communities and shifts of the alpine-nival ecotone are among the most commonly observed impacts of climate change. The Global Observation Research Initiative in Alpine Environments (GLORIA) network has developed a common methodology and facilitates a global approach for studying the effects of climate change in alpine ecosystems with repeated measurements in permanent plots. Mt Olympus, Greece, was the last target region to join the network. In this study we use the vegetation data from the baseline survey on Mt Olympus to describe floristic patterns along an elevational gradient of four summits. To examine compositional, life-form and chorological differences between- and within-summits we analyzed data from 32 plots. Moreover, we fitted generalized linear models to distinguish important environmental variables for the occurrence of plant taxa. Our results demonstrate that elevation was the dominant factor influencing vegetation changes along the examined gradients. Additional, the life-form spectrum does not provide sufficient information to be used as index for monitoring climate change impacts on vegetation composition. Instead, the use of the species matrix provides enough information regarding the between-summits dissimilarities. We also identified a number of plant taxa that are highly related to either low or high elevations. These taxa could be used as early warning indices of compositional shifts.

KEYWORDS:

• Alpine grasslands
• climate change
• GLORIA network
• monitoring
• special area of conservation GR1250001

Acknowledgments

We would like to acknowledge the support of the GLORIA office at BOKUW as well as of the Management Unit of the Olympus National Park for the administrative support of the project. Moreover, we would like to thank Dr A. Strid (Ørbæk) and Dr E. Eleftheriadou (Thessaloniki) for their assistance with plant specimen identification.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Author contributions

F.X.: Scientific coordination, data collection (summits 1, 2, 3 and 4), plant specimen identification, data analysis, MS preparation; G.P.: Administrative coordination, data collection (summits 1, 2, 3 and 4), MS preparation; Ch.D. and F-N. S: Data collection (summits 1, 3 and 4), plant specimen identification; M.T: Data collection (summits 1, 2 and 3); M.C.: Data collection (summits 1 and 3); A.E: Data collection (summit 2)

Data availability statement

The data that support the findings of this study are stored in the GLORIA network repository (gloria.ac.at) and are available from the corresponding author, F.X., upon reasonable request.

Additional information

Funding

The establishment of the GLORIA sites on Mt Olympus was financed by the project “Provision of services of specialized scientists for the establishment of a system for the monitoring of climate change on alpine habitat types on Mt Olympus and the inclusion of the area in the international program and network GLORIA” of the Act “Management Actions for protected areas, species and habitats in the area of responsibility of the Mt Olympus National Park Management Authority”, of the O.P. “Transportation Infrastructures, Environment and Sustainable Development 2014-2020”, which is included in the Public Investments Program. It is co-funded by the Cohesion Fund and it is included in the Priority Axis “ENVIRONMENTAL CONSERVATION AND PROTECTION – PROMOTION OF EFFICIENT USE OF RESOURCES (CF)” of the O.P. “Transportation Infrastructures, Environment and Sustainable Development 2014-2020” with MIS code 5033173 and Act code 2019ΣΕ27510018.