The degradation of subterranean habitats is believed to represent a serious threat for the conservation of obligate subterranean dwellers (troglobites), many of which are short-range endemics. However, while the factors influencing cave biodiversity remain largely unknown, the influence of the surrounding landscape and patterns of subterranean connectivity of terrestrial troglobitic communities have never been systematically assessed. Using spatial statistics to analyze the most comprehensive speleological database yet available for tropical caves, we first assess the influence of iron cave characteristics and the surrounding landscape on troglobitic communities from the Eastern Amazon. We then determine the spatial pattern of troglobitic community composition, species richness, phylogenetic diversity, and the occurrence of frequent troglobitic species, and finally quantify how different landscape features influence the connectivity between caves. Our results reveal the key importance of habitat amount, guano, water, lithology, geomorphology, and elevation in shaping iron cave troglobitic communities. While mining within 250 m from the caves influenced species composition, increasing agricultural land cover within 50 m from the caves reduced species richness and phylogenetic diversity. Troglobitic species composition, species richness, phylogenetic diversity, and the occurrence of frequent troglobites showed spatial autocorrelation for up to 40 km. Finally, our results suggest that the conservation of cave clusters should be prioritized, as geographic distance was the main factor determining connectivity between troglobitic communities. Overall, our work sheds important light onto one of the most overlooked terrestrial ecosystems, and highlights the need to shift conservation efforts from individual caves to subterranean habitats as a whole.

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Dentro v jogovzhodni Braziliji V članku opisujemo rezultate podrobnega kartiranja krasa v kvarcitu na 417 km 2 velikem območju v jugovzodni Braziliji. Z izjemo stolpov in udornic na območju ni površinskih kraških oblik, značilnih za karbonatni kras. Jame so najbolj značilen kraški pojav, čeprav je njihova gostota precej manjša od tiste na karbonatnem krasu. Na celotnem območju smo izmerili in detaljno raziskali 11 jam, ki so razvite plitvo in vzporedno s površjem. Glavna dejavnika razvoja jam sta litologija in hidravlični gradient. Petrografske analize kažejo, da je razvoj jam najbolj aktiven v območjih plitve freatične cone, kjer se v kvarcitu pojavljajo leče sljude (sericit) ter kjer sericit in železo obdajata kremenčeva zrna. V the območjih prihaja do razpadanja in mehanskega odnašanja zrn. V jugovzhodni Braziliji so kvarcitne jame pogost pojav, vendar so med seboj pravilpoma nepovezane, kar kaže na to, da v primerjavi s karbonatnim krasom v kvarcitu ne prihaja do razvoja velikih povezanih kraških drenažnih sistemov.

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