Ecological Model for Seral Stage Classification and Monitoring within a Greasewood/Western Wheatgrass-Blue Grama Ecological Type


  • Daniel W. Uresk USDA Forest Service, Rapid City, SD 57701


seral, greasewood, seral stage, western wheatgrass, blue grama, range management, eastern Wyoming, plant succession, cover frequency, transition models, greasewood ecological type, rangelands, Sarcobatus vermiculatus, Pascopyrum smithii, Bouteloua gracilis, canopy cover


A multivariate statistical model was developed to classify seral stages and to monitor vegetation within a greasewood-western wheatgrass-blue grama (Sarcobatus vermiculatus/Pascopyrum smithii-Bouteloua gracilis) ecological type.  Two key plant species, greasewood and western wheatgrass, provide the required information for the model to classify seral stages and monitor trends based on index values of both  plants (canopy cover (%) and frequency of occurrence (%)).  Three seral stages were quantitatively identified. Classification had an overall accuracy of 94% and all seral stages were significantly different (P < 0.05).  Three seral stages (late, intermediate and early) provide resource managers quantitative options to evaluate alternatives and objectives associated with steady states and transitions between and among seral stages.  Application of this model within the greasewood ecological type is simple to apply, repeatable, accurate and cost effective for field applications.






Biological Sciences - Terrestrial Ecosystems [Articles]