USDA Logo and Forest Service Shield

Ecological Classification and Monitoring

The ecological classification method of monitoring rangeland plant communities by seral stage was developed by Dr. Daniel Uresk, Senior Research Biologist for the U.S. Forest Service.

Data collection, classification, seral assignment, and monitoring are according to the method developed by Uresk (1990). Cluster and discriminant statistical techniques used to analyze field-collected data determined the presence of three to four seral stages defined by relationships of key plant variables for each type. Accuracy is 90% or greater for each type.

The following publication, which determined seral stages on mixed-grass prairie in South Dakota, presented the original concept. It is the source document for the procedures presented for all grassland and woodland vegetation types on this web page.


A site is classified, and assigned to a seral stage by entering values for a set of key plant variables into an Excel spreadsheet. The spreadsheet calculates site means and seral assignment.

Classification Types and Key Variables

Woodlands and Shrublands
Green Ash / Prunus spp./ Snowberry
basal area: Fraxinus pennsylvanica
canopy cover: Prunus spp.
Boxelder / Hackberry / Snowberry
basal area: Acer negundo
basal area: Celtis occidentalis
canopy cover: Symphoricarpos occidentalis
no. trees >1-inch: Populus deltoides
no. stems <1-inch: Populus deltoides
Average diameter: Populus deltoides trees
Hackberry / Prunus spp . / Snowberry
no. trees >1-inch: Celtis occidentalis
canopy cover: Prunus spp.
canopy cover: Symphoricarpos occidentalis
Bur Oak / Prunus spp. / Snowberry
basal area: Quercus macrocarpa
canopy cover: Prunus spp.
Big Sagebrush / Western wheatgrass / Blue grama
index:* Artemisia tridentata
index:* Agropyron smithii
index:* Bouteloua gracilis
Rocky Mountain Juniper / Littleseed ricegrass
basal area: Juniperus scopulorum
no. stems <1-inch: Juniperus scopulorum
canopy cover: Oryzopsis micrantha
Greasewood / Western wheatgrass
index:* Sarcobatus vermiculatus
index:* Agropyron smithii

* index = (% canopy cover) X (% frequency of occurrence)

Needle-and-thread / Western wheatgrass / Blue grama
index:* Stipa comata
index:* Agropyron smithii
index:* Bouteloua gracilis
Green needlegrass / Western wheatgrass / Buffalograss (Clayey)
index:* Agropyron smithii
index:* Buchloe dactyloides
index:* Stipa viridula
Western wheatgrass / Blue grama / Buffalograss
index:* Agropyron smithii
index:* Bouteloua gracilis
index:* Buchloe dactyloides
Big bluestem / Sideoats grama / Western wheatgrass (Shallow clay)
index:* Andropogon gerardii
index:* Bouteloua curtipendula
index:* Agropyron smithii
index:* Bouteloua gracilis
Sand bluestem / Little bluestem (Sands/Choppy sands)
index:* Andropogon hallii
index:* Bouteloua hirsuta
index:* Schizachyrium scoparium
Nebraska sedge / Baltic rush
index:* Carex nebrascensis
index:* Juncus balticus
Prairie sandreed / Little bluestem / Sedge spp. (Dry valleys)
index:* Calamovilfa longifolia
index:* Schizachyrium scoparium
index:* Carex spp.

* index = (% canopy cover) X (% frequency of occurrence)

For each ecological type, the following files are provided:

  1. A PDF file containing:
    • Explanation of seral stage assignment and monitoring for the type.
    • A graph showing changes and relationships of each key plant species from late to early seral stage.
    • Instructions on how to establish transects and plots, key variables and methodology to collect data. Information is provided on how to use the Excel file on a PDA or PC to enter data and obtain results.
  2. An Excel file - specific to each type - to install on a personal digital assistant (PDA) or personal computer (PC) for data collection and calculations.

WARNING: Be careful with the spreadsheet when loaded on a PDA. It is possible to erase formulas and stop the classification system. Always keep a backup copy!


  • Benkobi L., Uresk D.W., Child R.D. 2007. Ecological classification and monitoring model for the Wyoming big sagebrush shrubsteppe habitat type of northeastern Wyoming. Western North American Naturalist: Vol. 67, No. 3 pp. 347–358
  • Daubenmire, R. 1959. A canopy-coverage method of vegetational analysis. Northwest Science. 33(1):43-64.
  • SPSS 12.0 1989-2003. SPSS Inc. 444 N Michigan, Ave, Chicago, IL 60611. Copyright SPSS, All rights reserved.
  • Uresk, D.W. 1990. Using multivariate techniques to quantitatively estimate ecological stages in a mixed grass prairie. J. Range Mgt. 43(4):282-285.


Daniel W. Uresk
Senior Research Biologist
U.S. Forest Service
231 East St. Joseph Street
Rapid City, SD 57701

(605) 341-2808


Every effort is made to provide accurate and useful information. However, the U.S. Government, U.S. Department of Agriculture, the USDA Forest Service and their employees and contractors assume no legal liability for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed herein. Neither the U.S. Government, U.S. Department of Agriculture, the USDA Forest Service, nor their employees and contractors makes any warranty, express or implied, including the warranties of merchantability and fitness for a particular application. All indirect, consequential, implied, punitive and special damages are deemed waived if you use the information for each vegetative type in any manner. The sole remedy is the price paid or, at the seller’s choice, replacement or repair of the defective information.


This website should be cited as:

Uresk, DW; King, RM; Javersak, J; Juntti, TM. Ecological classification and monitoring.

US Forest Service, RGE
1400 Independence Ave., SW, Mailstop Code: 1103
Washington DC 20250-1103

Please contact us with questions or comments regarding this web. logo

Last modified: Thursday, 28-Mar-2013 15:56:19 CDT