Mammoth Cave: A Hotspot of Subterranean Biodiversity in the United States

Matthew L Niemiller,Rickard S Toomey,Kurt Helf

doi:10.3390/d13080373

Matthew L Niemiller, Rickard S Toomey + Show 1 more

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https://doi.org/10.3390/d13080373

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Abstract

The Mammoth Cave System in the Interior Low Plateau karst region in central Kentucky, USA is a global hotspot of cave-limited biodiversity, particularly terrestrial species. We searched the literature, museum accessions, and database records to compile an updated list of troglobiotic and stygobiotic species for the Mammoth Cave System and compare our list with previously published checklists. Our list of cave-limited fauna totals 49 species, with 32 troglobionts and 17 stygobionts. Seven species are endemic to the Mammoth Cave System and other small caves in Mammoth Cave National Park. The Mammoth Cave System is the type locality for 33 cave-limited species. The exceptional diversity at Mammoth Cave is likely related to several factors, such as the high dispersal potential of cave fauna associated with expansive karst exposures, high surface productivity, and a long history of exploration and study. Nearly 80% of the cave-limited fauna is of conservation concern, many of which are at an elevated risk of extinction because of small ranges, few occurrences, and several potential threats.

Highlights

The Mammoth Cave System in central Kentucky, USA is the most extensive cave system in the world with over 663 km (412 miles) of mapped passaged, including 27 entrances and 10 significant caves that have been connected since explorations began in the late 1700s: Colossal, Crystal (=Floyd Collins’ Crystal), Donkey, Hoover, Mammoth, Morrison, Proctor, Roppel, Salts, and Unknown caves
The Mammoth Cave obligate cave fauna is exceptionally rich with 49 troglobionts and stygobionts, making it one of the most diverse systems globally [37,225,226]
High species richness in the Mammoth Cave System may reflect the long history of more intensive sampling and study compared to other cave systems in the region [37]

Summary

Introduction

The Mammoth Cave System in central Kentucky, USA is the most extensive cave system in the world with over 663 km (412 miles) of mapped passaged, including 27 entrances and 10 significant caves that have been connected since explorations began in the late 1700s: Colossal, Crystal (=Floyd Collins’ Crystal), Donkey, Hoover, Mammoth, Morrison, Proctor, Roppel, Salts, and Unknown caves. Crystal, Salts, and Unknown caves comprise the 206 km (128 mile) Flint Ridge Cave system (Figure 1). The Mammoth Cave System was recognized as a UNESCO World Heritage Site in 1981 because of its uniqueness as the world’s longest cave system as well as its extensive geological, mineral, and biological resources. The Mammoth Cave System is developed in three major limestone layers at the northwestern extent of the Pennyroyal Plateau, an expansive flat karst plain within the Interior Low Plateau physiographic province.

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