Ecological Model for Seral Stage Classification and Monitoring with Key Plants on Sandy Ecological Sites in Nebraska and South Dakota

The objectives were to develop a multivariate model (state and transition) to define and classify seral stages with capabilities that enable us to monitor vegetation changes with three key plant species within a sandy ecological site located in the Sand Hills of Nebraska and South Dakota.  Three key plant species, prairie sandreed (Calamovilfa longifolia) /little bluestem (Schizachyrium scoparium)/sun sedge (Carex inops) provided inputs for the model to classify seral stages and to monitor vegetation transitions based on index values (canopy cover (%) x frequency of occurrence (%)) from field measurements within the full range of natural variability.  The model does not require a straight progression through all seral stages or plant phases but may go through multiple stages or remain at a steady state.  Four seral stages that represent early to late succession provided an assignment accuracy of 90 percent.  Seral stages were significantly different (P<0.05) from each other.  Application of the model to predict seral stages and vegetation monitoring is accurate, quantitative and free of subjective judgments.