Headwater wetland meadows of the Western U.S. have great ecological value despite their limited aerial extent. The ability of meadows to perform important ecosystem functions can be impacted by human uses and management activities. Soil properties are important indicators of site quality and function. The major purpose of this project was to evaluate various soil characteristics, especially soil organic carbon (SOC), and interrelations with vegetation and hydrologic properties in montane and subalpine riparian-wetland meadows of the Sierra Nevada in the contexts of livestock grazing and hydrologic condition. Physical and chemical properties of whole soil solum samples and soils sampled by pedogenetic horizon were assessed in nineteen hydrologically functional meadows representing a range of livestock utilization in the Sierra National Forest. In addition, vegetation community composition and physical and chemical characteristics of whole solum soil samples were evaluated in riparian meadows representing a range of hydrologic condition as defined by the Properly Functioning Condition (PFC) method in the Stanislaus National Forest. Average total SOC contents were variable among meadows, but were considerably high on average at 37.2"2.87 kg C m -2 in the Sierra NF and 14.2"0.78 kg C m -2 in the Stanislaus NF. Soil moisture appeared to be an important driver of total SOC contents, while livestock utilization did not appear to influence overall C storage in hydrologically functional meadows. However, soils of more heavily grazed areas were more compacted and had slightly higher NO 3 - -N contents than more lightly grazed areas. Results of this study suggest any management activities that affect the hydrologic regime will likely impart undesirable changes in soil characteristics and plant communities.

Riparian meadows of the Western U.S. are crucial to sustaining aquatic habitat, water quality, water supply and carbon storage. The ability of riparian meadows to provide these services can be impacted by human uses and management. We investigated soil carbon and nitrogen quality and distribution in high elevation riparian meadows of the Sierra Nevada. Meadows were selected based on riparian conditions as defined by the Properly Functioning Condition method. Nineteen meadows in Stanislaus National Forest (SNF) were selected to represent four main categories within a range of conditions: properly functioning, at-risk and degraded. Soil physical and chemical characteristics were evaluated across each meadow at three slope positions: forest edge, mid-slope and streambank. Whole-solum composite samples were obtained by driving a sampler to a depth where unsorted parent material was present. Four soil samples located 10 m apart were homogenized resulting in a whole- solum composite sample from each slope position. A soil profile was described at each slope position. Channel width and average bankfull depth were measured for each stream. Our results show riparian meadows in SNF have high variation in soil and channel characteristics. Even so, meadows show trends related to condition. Functional meadows have over 40% more soil organic carbon (SOC), total nitrogen (TN) and soil water content (SWC) compared to non-functional meadows. Differences in SOC and SWC are driven by an interaction between meadow slope position and condition class. In addition, SOC and TN in mid-slope surface horizons are more than 50% higher in functional meadows compared to non-functional meadows. Results suggest with proper restoration efforts, riparian meadows can demonstrate potential for enhanced SOC storage.

"This completely new edition of Terrestrial Vegetation of California clearly documents the extraordinary complexity and richness of the plant communities and of the state and the forces that shape them. This volume is a storehouse of information of value to anyone concerned with meeting the challenge of understanding, managing or conserving these unique plant communities under the growing threats of climate change, biological invasions and development."—Harold Mooney, Professor of Environmental Biology, Stanford University "The plants of California are under threat like never before. Traditional pressures of development and invasive species have been joined by a newly-recognized threat: human-caused climate change. It is essential that we thoroughly understand current plant community dynamics in order to have a hope of conserving them. This book represents an important, well-timed advance in knowledge of the vegetation of this diverse state and is an essential resource for professionals, students, and the general public alike."—Brent Mishler, Director of the University & Jepson Herbaria and Professor of Integrative Biology, University of California, Berkeley