Past and Present Resiliency of a Rocky Mountain Fen

Abstract

Groundwater-fed peatlands—or fens—are stable hydrologic systems resistant to warming temperatures and wildfires due to perennial saturation. In climatically sensitive mountain systems, fens provide hydrologic safe havens for rare plants and animals. This study focuses on a mountain fen in the front range of the Rocky Mountains to determine past and present resiliency of the fen and nearby areas. Charcoal deposits provide fire disturbance indicators where large and numerous charcoal fragments signify local fires that affected the fen or nearby areas. Radiocarbon dating was used to estimate peat accumulation rates between fire events where faster or slower rates are associated with relatively wetter or drier climates. The study utilized ground penetrating radar (GPR) surveys to identify ideal core locations and calculate average peat depth. The longest core was used for charcoal volume fraction and carbon dating. Additionally, modern surface and atmospheric surveys were conducted to evaluate the modern resiliency of the fen and adjacent area. Results suggest peat initiation in the mountain fen began 3,690 years ago. At least two significant fire events occurred since initiation, and little or no mineralization altered the peat. This study investigates past and present resiliency of a mountain fen by combining paleoecological and modern atmospheric/surface data.