Department of Agriculture
Dataset Description
The USDA-ARS conducted a five-year study of transpirational water use of single-leaf pinyon (Pinus monopylla) and Utah juniper (Juniperus osteosperma) at the Porter Canyon Experimental Watershed (PCEW) in the Great Basin of Nevada, USA. A total of 29 pinyon and 16 juniper trees that were representative of the natural size-class variation within the PCEW were selected for long-term sap flow measurements. All trees were instrumented with two sets of 2 cm Granier-style thermal dissipation sap flow probes, as tree core measurements obtained in late 2011 indicated that sapwood depth was greater than 2 cm on average for all trees. Two sets of probes were installed radially into the xylem at approximately north-south orientation, depending on branch architecture, and spaced 15 cm axially with the top probe approximately 50 cm above the ground. This dataset is comprised of nine .CSV files covering the five-year period. The five-year period encompassed five water years from October 1st, 2013 to September 30th, 2018. The dataset includes measurements of mean daily vapor pressure deficit, solar radiation, and volumetric water content at 20 cm. The data set also includes mean daily sap flux density, mean daily whole tree volumetric water use, mean daily water use per basal area, and scaled daily site water use. Lastly, the dataset includes the relationship of mean daytime sap flux density to mean daytime vapor pressure deficit for days within the growing season time periods when: 1) soil volumetric water content was not a sap flux-limiting factor and 2) soil volumetric water content was a sap flux-limiting factor.
Organization: Department of Agriculture
Organization URL: https://catalog.data.gov/organization/usda
Last updated: 2025-11-21
Tags: Utah juniper, ecohydrology, single-leaf pinyon, soil volumetric water content, solar radiation, thermal dissipation probes, transpiration, vapor pressure deficit