Ecology of Blanchard Springs Caverns, Ozark National Forest, Arkansas, 40 years later

Karst regions and their associated underground caverns provide a specialized laboratory with a relatively stable climate and well-defined borders.  Interrelationships between these subterranean environments and the above ground epigean environment affect dispersion and distribution of cave organisms among the macro and microhabitats.  This study contributes to a better understanding of the seasonal fluctuations of the abiotic and biotic parameters needed to protect fragile ecosystems.  The current study, funded by a NSF Noyce grant and the U.S. Forest Service, duplicates the baseline study to determine the effects of 40 years of tourism on Blanchard Springs Caverns. The baseline study was initiated, in 1972, before the caverns were opened to the public.  One new entrance, numerous trails, and incandescent lighting were added after the initial study.  The limestone cave system is located in the Sylamore Ranger District of the Ozark-St. Francis National Forest, fifteen miles northwest of Mountain View, Stone County, Arkansas.  Water quality measures, fauna counts, and temperature sensors, placed in three zones (the twilight, the variable temperature, and the constant temperature) throughout the caverns, monitored changes during the yearlong study.  The results were compared with baseline measures. Epigean fluctuations occurred in the twilight zone, but no changes was recorded over 40 years in the deeper constant temperature zones of the caverns. Temperatures in the constant temperature zone were 14°C, the annual mean temperature of the region.  Water quality measurements were dissolved Oxygen, 8 mg/L; total hardness, 153.9 mg/L; and alkalinity, 95 mg/ L of CaCO 3 .  The only measurement that varied was pH, with the baseline value being pH 8.2 and the current value being pH 7.  New species of invertebrates were recorded compared with the baseline study.  Gray Bat,  Myotis grisescens , winter populations and distributions were found to have increased dramatically from approximately 6,000 bats prior to 1963 to 372,726 in 2016.  The research is of special importance because the caverns are a winter hibernacula for the endangered Gray Bat,  Myotis grisescens , and other rare cave organisms that are susceptible to white-nose syndrome,  Pseudogymnoascus destructans .  These results suggest limited, if any, disturbance to the fragile ecosystems of Blanchard Springs Caverns due to tourism.  In fact, the cave system appears to have improved since the baseline study.  This may be due to limited and supervised access, especially during winter months, and strong conservation-minded leadership. See more of:  Conservation Management II