Ammonia volatilization in a Mexican bat cave ecosystem

(Uploaded by Plazi for the Bat Literature Project) Direct measurements of gaseous ammonia in the atmosphere of a dry bat cave containing several million insectivorous bats revealed a peak concentration of 1779 ppm (0.96 mg/drrr'). Observations indicate that the origin of the gaseous ammonia is rapid microbial decomposition of bat urea, not chitinous guano. Modelling of ammonia distribution and diffusion indicates that ammonia production at the Cueva del Tigre is ~257 g NH3/day, equivalent to the decomposition of ~454 g urea/day. Ammonia production is also characterized by significant isotopic fractionation favoring isotopically light (5 15N depleted) ammonia.