Vegetation

This indicator describes rangeland plant communities and their area at any given time, with the difference between times being a reflection of temporal changes. This indicator is the hierarchical subcomponent of the “Extent of Land Area in Rangeland” indicator. Changes in certain plant communities could result in changes in resource outputs, ecosystem services, non-market values, and habitats for plant and animal species. Changes in plant communities over time may suggest changes in underlying environmental factors such as climate and nutrient availability, changes in ecosystem functioning, or changes in disturbances (including grazing).

Adequate seed production is essential to maintain populations of plants when sexual reproduction is the primary mechanism of individual plant replacement at a site; however, annual seed production of perennial plants is highly variable. Comparing number of seedstalks and/or number of seeds per seedstalk of native or seeded plants (not weeds or invasives) in the evaluation area with that produced on the associated ecological reference area (ERA) can be used to assess seed production.

Livestock grazing is the historical economic use of rangelands and continues to be an important use on both public and private lands. Changes in the value of forage used by grazing animals can indicate change in rangeland sustainability because they suggest increased (or decreased) pressure to harvest vegetation as forage to the exclusion or detriment of other uses or values. Forage values can also indicate quality of the forage in a particular area.