Spatial analysis of orchids diversity unveils hot-spots: The case of Zante Island, Greece

Abstract

The current study aims to analyze the ecological niche and mapping the distribution of species belonging to Orchidaceae family, in Zante Island and to determine hotspots at sites of high species richness. 967 observations were recorded into 110 tracks in 2015 and 120 tracks in 2016, where 47 orchid species were identified belonging to 9 genera. Using Maxent, the ecological niche of each species was analyzed and habitat suitability map was created using 12 environmental parameters. The suitability maps were transformed into a binary format according to the threshold “10th percentile training presence” and the transformed maps used to compute hot-spot regions by applying the SMD toolbox using the software ArcGIS. Zante Island is characterized by remarkably high orchid species richness since the synthetic model indicates presence of at least 10 species for the 53.2% of the island area. Topography, geology and landscape openness are determining factors for orchids’ diversity conservation. Altitude is the determining factor of differentiation in species distribution. Hydro-lithology was the following most significant interpreting parameter. The mapping analysis of species abundance units revealed that 12.5% of the island surface could be characterized as hotspots of high value for the conservation of orchid diversity.