RCCZO -- Soil Respiration, Soil Biogeochemistry, Climate -- Antecedent Effects on Soil Respiration -- Reynolds Creek Experimental Watershed -- (2016-2018)

Soil carbon is the largest terrestrial carbon (C) store but remains a large source of uncertainty in C storage models due to high temporal and spatial variability, and a lack of process understanding. Carbon dioxide (CO2) fluxes are especially difficult in desert ecosystems exhibiting pulses of biogeochemical cycling regulated by antecedent soil conditions. Using the soil CO2 gradient method and measures of soil physical and hydrologic properties, we present a soil respiration model for a cold desert climate and which incorporates antecedent controls on CO2 emissions using Bayesian methods. Soil properties and CO2 measurements between October 2016-2018 were taken from a catchment at 2111 m elevation within the Reynolds Creek Critical Zone Observatory (CZO). Mean annual precipitation is snow-dominated and averages 800 mm. Mean annual temperature is 5.6 °C. Vegetation is dominated by various sub-species of sagebrush. Lithology was derived from basalt and Rhyolitic welded tuff. Soil CO2, soil moisture, and soil temperature sensors at 5 depths within the soil profile recorded every 30 minutes from October 2016 to June 2018. Rates of CO2 efflux and production used modeled soil porosity and hydraulic characteristics to account for changes in diffusivity with variable soil moisture.