Rangelands are a dynamic landscape, composed of many resources, that produce many products. The rangeland landscape and its resources are constantly being modified by a suite of non-human forces, including:
Humans also modify rangelands directly through development (e.g., energy, mining, and transporation and communications infrastructure) and recreation. People also affect the other forces of change by introducing invasive species, controlling or igniting fires, managing grazing and potentially impacting the climate and weather patterns through human caused changes in atmospheric chemistry .
Managers need a way to predict how management practices or natural disturbance will impact the vegetation on rangelands, so they developed State and Transition Models. State and transition models are box-and-arrow diagrams used to describe vegetation change, or plant succession, from a specific disturbance based on the current vegetation community, the soils and climate of a site.