78 New Frontiers in Cave and Karst Science

We encourage submissions in any field of cave and karst science, with special emphasis on novel techniques, interdisciplinary approaches, and contributions from diverse early career researchers (students, postdocs, and faculty).

Monday, 20 October 2025
8:00 AM - 12:00 PM
HBGCC, 211

Surface water and groundwater interface controls on microbial N2O cycling in karst aquifers

Paper number: 78-8
Program: Technical Sessions
Time: 9:50 AM – 10:05 AM

Authors

Abstract

Karst landscapes and aquifers have recently been identified as significant sources of nitrous oxide (N2O), the third most abundant greenhouse gas, with a global warming potential approximately 300 times greater than that of carbon dioxide. Despite this, the exact processes driving N2O production in karst systems remain poorly understood. In this research, we integrate field studies with microfluidic experiments to investigate how surface water–groundwater (SW-GW) interactions influence N2O cycling in karst aquifers. At SW-GW interfaces within a karst aquifer, we collected groundwater samples to measure N2O concentrations under different mixing conditions. In parallel, we used microfluidic devices that replicate karst environments to simulate SW-GW mixing and observe microbial N2O cycling. By connecting the outcomes of these laboratory experiments with field measurements, we demonstrate that inputs of dissolved oxygen from surface water into anoxic groundwater inhibit the completion of denitrification, consequently leading to the accumulation and atmospheric release of N2O from karst aquatic systems.

Geological Society of America Abstracts with Programs. Vol. 57, No. 6

doi: 10.1130/abs/2025AM-414625

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