Environmental factors shaping copepod distributions in cave waters of the Lessinian unsaturated karst (NE-Italy)

The unsaturated karst represents a transitional zone connecting the land surface to water table of underlying saturated through percolating and small perched aquifers. It constitutes significant groundwater reservoir hosts high biodiversity specialized endemic species. Whereas investigating this ecotone can shed light on invertebrate diversity whole system, ecological studies in have been hampered by access, mapping, sampling challenges. We studied 52 caves Lessinian Massif (NE-Italy), which is dominated carbonate rocks interspersed with spot areas composed mainly igneous rocks. Our aim was understand historical factors may shaped distribution crustacean copepods at regional spatial scale karst. collected 33 species belonging orders Harpacticoida Cyclopoida. Species richness estimators related accumulation curves suggest an exhaustive effort. A hydrologic analysis performed Geographic Information System environment divided study area three distinct drainage basins: Eastern Lessini, Core, Western Lessini. Regression analyses indicated that non-stygobitic (i.e., surface-water exploit for different purposes) driven inter-basin differences. Richness stygobitic obligate dwellers) instead strongly lithological features responded negatively thermal variability. Next, we used kernel density estimation spatially explore patterns area. highest harpacticoids identified basin, lithologically more heterogeneous surrounded practically non-aquiferous limit dispersal. Conversely, basin hosted cyclopoid This pattern suggests colonization pathways two taxa, strong effect hampering dispersal most harpacticoids. Lithological barriers seemingly did not affect copepods, were found across Altogether, these results emphasize key role played interaction hydrological features, climate, lithology determining copepod