Fire Impacts on Soil Hydraulic Properties in a Sagebrush Ecosystem in Nevada

Covering approximately one third of the United States of America, sagebrush-dominated ecosystems are an important part of the continental USA’s landscape. The effects of wildfires on the hydrology of semi-arid sagebrush ecosystems are poorly understood and, as these areas experience more frequent wildfires, are becoming more relevant. As part of a multi-disciplinary project studying wildfire in sagebrush ecosystems – “Harnessing the Data Revolution for Fire Science” – a field experiment near Reno, Nevada, was set up to better understand the effects of fire on the hydrology of sagebrush ecosystems by measuring the hydraulic properties of the soil before and after prescribed burning. In the spring of 2024, twenty 3x4 meter experimental plots were outfitted with instruments for soil moisture and temperature monitoring; at least 2 TOMST TMS4 probes were placed in each plot in areas with different post-fire vegetation, recording measurements at 15-minute intervals. These data are supplemented with intermittent measurements of shallow soil moisture using a Campbell Hydrosense II Probe to measure a greater number of points within each plot. The two instruments were calibrated in the lab with soil from the experimental plots to ensure accurate and comparable volumetric water content values. Infiltration and water repellency measurements under different vegetation covers within each plot provide context for interpreting variations in the soil moisture data. In fall 2025, 10 of the 20 experimental plots will be burned, which will allow us to compare the hydraulic properties of the same soil before and after the fire, therefore directly assessing fire impact on soil hydrologic properties. Here we introduce the field experiment and address the calibration of the Campbell HydroSense II and TOMST TMS4 soil moisture probes, while also providing a site characterization with the first year of pre-fire soil moisture, temperature, infiltration, and water repellency data.