The diversity of plant species in western Slovenia (most of the Alpine region, Slovenian submediterranean region with Kras and part of Istria) with 800 or more taxa within approximately 140 km2 (basic field of four quadrants) is considerably higher than in the central and eastern parts of Slovenia.
The trend of extinction of endangered plant species is noticeable in Slovenian Istria, in the extreme east of Slovenia in the Mura floodplain, in the extreme east of the Sava basin in Slovenia (Prilipe, Jovsi, Dobrava), partially in the western Karawanken Range and in the northern spurs of the Dinaric Mountains. Also, a slight concentration of extinction of endangered flora is noticeable in the Pohorje Massif and in the Slovenske gorice hills. An apparent improvement of conditions is dispersed throughout Slovenia with several indistinct concentrations in the upper Soča Basin, the eastern Kamnik Alps and Bela krajina.
Richness of plant species is mostly related to diversity of habitat types, which, in turn, depends on various factors ranging from natural geographic (altitude range, solar exposure, geological structure) to florogenesis-related and pure anthropogenic (intensity of impacts on nature, urbanisation, extensiveness of farming, etc.).
The indicator shows the species richness of plant species for different periods, based on the available data. All the data for the last 50 years were taken into account for the estimate of species richness of higher plants, i.e. the period 1957–2006, while comparisons were made for the periods 1987–1996 (approximately 100,000 pieces of data) and 1997–2006 (approximately 130,000 pieces of data). Threatened plant species are presented in more detail (trends showing their changing share within the flora of a certain quadrant in the periods compared).
Raw input data contained over 500,000 data points on the presence of species of vascular flora within the territory of Slovenia. Among the available data, only that with sufficient topographic accuracy was selected so it could be undisputedly placed into the grid of 35 km2 quadrants.
· To preserve a high level of biodiversity and to halt the decline of biodiversity by 2010:
· to preserve or to achieve a favourable state of species and habitat types;
· long-term stabilisation or increase in the share of threatened plant species within the flora of a certain quadrant.