Positive relationship between genetic- and species diversity on limestone outcrops in the Carpathian Mountains

• We tested for parallel patterns of genetic- and species diversity.
• We examined mainland limestone outcrops at local and regional geographic scales.
• A strong positive relationships exists between the genetic- and species diversity.
• The parallel patterns are driven by similar landscape level mechanisms.
• The landscape matrix effect may differentiate mainland islands from oceanic islands.

We asked if the genetic diversity of Saponaria bellidifolia (a habitat specialist plant) and the species diversity of its habitat are driven by parallel landscape level processes in an island-like system of limestone outcrops in the Carpathian Mountains. We tested the relationship of these two diversity levels at local and regional geographic scales. Local genetic and species diversity showed parallel patterns influenced by the number of plant communities. Likewise, at regional level there was strong evidence for parallel equilibrial dynamics of genotypes and species. However, a superimposed matrix effect enhanced the regional species diversity only. Genetic diversity of habitat specialist organisms and species diversity of these limestone outcrop islands on mainland are modulated by parallel landscape-level processes at different geographic scales, and mechanisms may be identified at very high spatial resolutions.