Historic Range of Variability for Meadows in the Sierra Nevada and South Cascades

Natural Range of Variation (NRV) assessments (essentially equivalent to Historical Range of Variation [HRV] assessments) provide baseline information on ecosystem conditions (composition, structure, and function) that can be compared to current conditions to develop an idea of trend over time and an idea of the level of departure of altered ecosystems from their “natural” state (Morgan et al. 1984, Manley et al. 1995, Landres et al. 1999, Wiens et al. 2012; see Methods). These trend assessments form part of the basis for the assessment of ecological integrity that is required in the 2012 Forest Service Planning Rule. NRV assessments were carried out for 11 terrestrial ecosystems by the Pacific Southwest Region Ecology Program between October, 2012 and May, 2013, using historical information (primarily from the pre-Euroamerican period, 16th century to the mid-19th century) as well as information from modern-day reference ecosystems and other sources. This is the meadow NRV assessment.