Habitat Conditions of Montane Meadows associated with Restored and Unrestored Stream Channels of California

Abstract

Mountain meadow habitats are valued for their ecological importance. They attenuate floods, improve water quality, and support high biodiversity. Many meadow habitats in the western US are degraded, and efforts are increasing to restore these montane meadow ecosystems. Rewatering projects such as pond-and-plug quickly raise the water table by blocking the existing incised stream channel and can result in the rapid recovery of wet meadow habitats. Based on the existing literature, however, it is difficult to determine realistic expectations for outcomes of restoration projects across a range of hydrogeologic conditions. We compared wetland, vegetation, soil carbon, and channel condition variables between ten randomly selected restored and ten paired unrestored montane meadows in California to provide a comparison of habitat conditions. We found that unrestored meadows had a higher proportion of wetland habitat, fewer indicators of channel instability, and greater topsoil carbon stores compared to restored meadows. Restored meadows had more herbaceous biomass within their wetland habitats, but also had more cattle exclosures. The restoration category of the meadow remained important when watershed variables were included in models. While restored meadows were highly degraded prior to project implementation, our results suggest that, in general, conditions do not improve beyond the average conditions of nearby unrestored meadows. Realistic expectations of outcomes and consequences are necessary for managers to make appropriate decisions about restoration options and whether or not to implement rewatering projects that often greatly alter the meadow landscape.