HOW IS MAMMOTH CAVE NATIONAL PARK DOING? THE 2018 MACA NATURAL RESOURCE CONDITION ASSESSMENT

Great teachers touch, and sometimes change, lives. The essentially single entity known widely as Art-n-Peg Palmer has impacted generations of students since 1980 through their Western Kentucky University Karst Geology course at Mammoth Cave National Park (MACA in NPS-speak). Art-n-Peg have returned to Mammoth Cave again and again, and surely their world views have been deeply informed by their time above and below ground at this very special place.

It is indeed a special place. We describe here a new, comprehensive analysis of MACA and its resources—above ground, below ground; geological, biological, hydrologic, atmospheric and astronomical. We conclude that this is a well understood, well cared for, and carefully protected national park, and judge many resources to be in good condition or even improving. Improvements in regional coal combustion have, for example, raised rainfall pH by a whole unit, dropped rain SO₄ by 75%, and improved visibility. Even though the world’s longest known cave is the basis for the park being here, the Green River has nationally significant biodiversity, and the park protects numerous threatened and endangered species, sensitive wetlands and rare plants. There are also challenges: White Nose Syndrome has killed at least 70% of at least three species of bats, emerald ash borers now threaten the park’s ash trees, and one day hemlock wooly adelgids may impact the beautiful (and rare this far west) hemlocks in the valleys of Bylew Creek and Cubby Cove.

Interrelationships become clear in this kind of holistic examination. Slender glass lizards and some bird species, once relatively common in the pre-park open farmland, are being extirpated from the park as the pesky forest trees take over.

Conclusions are based on quantitative data. Many cavers (including Art-n-Peg) have come out of Mammoth Cave at 3 am after a long cave trip on some winter night and walked back to the car through the cold, wholly exhausted but still staring up at the Milky Way streaming across a beautiful dark sky. This is another special MACA feature, increasingly rare in the eastern US: most of the park has a Class 4 rating on the Bortle Scale as well as consistent Unihedron Sky Quality Meter (SQM) readings over 21.0, which qualify it for Silver Tier Status from the International Dark Skies Association for “exemplary nighttime landscapes.”