Ongoing Vegetation Transect Data
This section provides access to all measurements of vegetation by species or species group made on the Ongoing Vegetation Transects at the SRER since 1953. Each database is available for download as Excel Workbook files (*xls). Data Layouts and Notes as Word files (*docx) are also provided for each database to guide the data use.
The parameters repeatedly measured on the transects and provided below include:
- Cover
- Density
- Fetch (useful for detecting the spatial pattern of plant cover)
- Grass basal diameter and biomass
Figures associated with these data and showing trends over the years are available at Figures for cover, density, and perennial grass biomass.
Vegetation Transect Coordinates and Ecological Site Designation can be accessed at UTM Coordinates and Ecological Site Designations for the Ongoing Vegetation Transects.
For more information about the measurement protocols visit Ongoing Vegetation Transect Measurement Protocols.
The file 'ltcover' available below for download includes the long-term cover measurements repeatedly made on
131 transects since they were established as early as 1953 in USFS Studies FSRM 1706-09, FSRM 1706-12, FSRM 1706-15, and FSRM 1706-25.
See the associated 'ltcovlayout' and 'ltcovnotes' files for more information about the data records included in the database, the history of the transects, the cover measurements, and the plant species recorded on the transects.
The file 'ltden' available below for download includes the long-term density measurements made on
131 transects established in USFS Studies FSRM 1706-09, FSRM 1706-12, FSRM 1706-15, and FSRM 1706-25. The file includes all measures of density repeatedly made on these transects since 1972.
See the associated 'ltdenlayout' and 'ltdennotes' files for more information about the data records included in the database, the history of the transects, the density measurements, and the plant species recorded on the transects.
The file 'ltfetch' available below for download includes the long-term fetch measurements made on
131 transects established in USFS Studies FSRM 1706-09, FSRM 1706-12, FSRM 1706-15, and FSRM 1706-25. This file includes all measures of fetch made on these transects in 2009 and 2012.
See the associated 'ltfetchlayout' and 'ltfetchnotes' files for more information about the data records included in the database, the history of the transects, the fetch measurements, and the plant species recorded on the transects.
The file 'ltfbasaldiametermass' available below for download includes the long-term basal diameter measurements made on 131 transects established in USFS Studies FSRM 1706-09, FSRM 1706-12, FSRM 1706-15, and FSRM 1706-25. This file includes all measures of basal diameter made on these transects since 2009. Grass mass is estimated using an allometric equation developed on the Santa Rita Experimental Range (Nafus et al. 2009. Rangeland Ecology and Management 62:68-720), and the value represents the mass produced at the end of the most recent summer growing season. In 2021, no basal diameter measurements were made because the extremely dry conditions in the summer of 2020 resulted in very little growth of perennial grasses, and many plants appeared to be dead in the winter and spring of 2021. Under these conditions, we could not be certain that basal diameter would represent biomass produced in the previous summer in the same manner as all the other years when measurements were made.
See the associated 'ltbasaldiametermasslayout' and 'ltbasaldiametermassnotes' files for more information about the data records included in the database, the history of the transects, the basal diameter measurements, the biomass estimation, and the plant species recorded on the transects.