ES-11. Examining the Effects of Rising Air Temperature on Nitrogen Cycling and Trace Gas Emissions in the Alpine

Abstract
Determining how rising air temperature is affecting the nitrogen cycle and trace gas emissions in alpine ecosystems is critical to inform the protection and conservation of these sensitive environments. Rising air temperature can increase nitrogen cycling rates and induce earlier and longer growing seasons. An accelerated nitrogen cycle can help alleviate nitrogen limitation in plants but also may cause plant species composition change. Moreover, excess nitrogen in the environment can have several negative effects, including soil acidification and nitrogen leaching to N-limited aquatic ecosystems. Additionally, a warmer environment can stimulate microbial activities, which can produce greenhouse gases (i.e., CO2, CH4, N2O) through processes like soil respiration and denitrification and alter the greenhouse gas budget. To quantify these effects, I will be collaborating on Niwot's Turf Transplant experiment, which will transplant alpine turfs (25 cm x 25 cm x 10 cm) into the subalpine. I will take bi-monthly 0-10 cm soil cores to measure the physical and chemical properties of the soils. Additionally, I will be quantifying inorganic nitrogen concentration and net N mineralization and nitrification rates to understand how the alpine N cycle is changing with rising air temperature. To measure soil greenhouse gas fluxes, I am following methods by installing in-situ soil chambers and taking measurements over an hour. My research at Niwot Ridge will help us better understand how rising air temperature may drive these changes, which can inform management strategies and the protection of the Colorado Rocky Mountains alpine ecosystem.