Print PageCalifornia’s Sierra Nevada ecosystem provides a variety of natural resources ranging from forest products, livestock, food, water, to recreation and tourism. Sierra waterbodies contribute 65% of California’s developed water supplies, thereby supporting the richest agricultural valley in the nation and the seventh largest economy in the world. Meadows comprise less than 10% of the area within the Sierra Nevada, but are disproportionately influential in terms of hydrologic and ecosystem functions. Meadows provide grazing forage, wildlife habitat, groundwater recharge, carbon sequestration, human recreation, and water pollutant, flood, and sediment attenuation benefits. By some estimates, 40-60% of Sierra meadows are currently impacted as a result of over-grazing, erosion, lowered groundwater tables, and altered plant communities. This has prompted large and increasing investment in Sierra meadow restoration. The goals of this study were to accurately delineate Sierra meadows, and to develop a rapid and repeatable methodology to assess meadow ecological condition and hydrologic function. The Yuba River Watershed was used as a case study to test a rapid meadow assessment method (Meadow Condition Scorecard [MCS]), assess the scorecard’s ability to quantify meadow function and level of degradation, and thereby assist in meadow restoration prioritization.
Results/Conclusions
The MCS was adapted from previously established methods for scoring riparian habitat condition to specifically target Sierra meadow systems. Criteria were designed to quantify meadow function primarily relating to: vegetation composition; channel and bank condition; and metrics of disturbance. This methodology was field-tested on 26 meadows in the summer of 2009, and meadow ranking was distributed as follows: 50% natural condition, 39% slightly impacted, 12% moderately impacted, and 0% heavily impacted. Assessment condition was included as one of four primary components for prioritizing meadows for restoration. In addition, the California Department of Fish and Game’s currently used desktop delineation method was ground-truthed, it and found that desktop delineations overestimate meadow size by 52% ± 8 %. It was determined that overestimation can to be attributed to the inclusion of riparian areas with steep-slopes (> 6%) and thickets of alders (Alnus sp.) and willow (Salix sp.) species in the desktop classification.
These results indicate that 50% of meadows in the Yuba watershed are impacted, which agrees with estimates Sierra-wide. The MCS further provides a tool to quantify and determine the types of impacts which and can be applied during a short (2-hour) assessment and used to inventory meadow resources and prioritize impacted meadows for restoration.
