Impact of root system type and elevation on the richness and distribution of orchid flora in the Czech Republic
Abstract
Understanding diversity patterns along elevational gradient and the effect of global change on abundance, distribution patterns and survival of species, especially of the most endangered ones, are two highly discussed topics in biodiversity research. Here we compare the distribution patterns of orchid taxa in six floristic areas of the Czech Republic and explore specific trends in the data within each of these areas.
We use data on 69 terrestrial orchid species and subspecies recorded in the Czech Republic and classify them according to their root system into three categories - rhizomatous, intermediate and tuberous orchids. Using available distributional data on these species and interpolate them in 100-m elevational intervals along the entire elevational gradient of each floristic area.
Six OMI analyses were performed to calculate the niche breadth of the orchid species studied. Using regression techniques, we explored how orchid species richness and mean niche breadth depend on elevation for each of the three orchid categories separately.
Most of the coefficients of determination in these regressions were high and statistically significant. The most widely distributed orchid group in the Czech Republic were the rhizomatous orchids, followed by intermediate and tuberous ones.
Both species richness and mean niche breadth have shown different trends between the orchid groups studied. These patterns are probably strongly influenced by the orography of the country, in combination with the distribution of different habitat types in the six floristic areas of the country.