1. Introduction Limestone karsts, with their unique physical and chemical substrates, shape a range of microhabitats and unique island habitats, such as karst caves, and terrestrial islands [1]. These special habitats have ecological conditions that significantly differ from the surroundings and thus provide relatively isolated environments for species isolation and differentiation [2,3]. Karst areas have harboured a high level of plant richness and endemism through a long period of evolution [2].
