Previous studies have addressed the

Previous studies have addressed the effects of groundwater pumping on riparian ecosystems, coastal wetlands, prairie potholes, and intermittent ponds (Winter, 1988; Bernaldez et al., 1993; van der Kamp and Hayashi, 1998; Alley et al., 1999). Groundwater pumping in riparian areas can result in the death of leaves, twigs and whole trees, such as cottonwoods (Cooper et al., 2003). However, little is known about the long-term effects of groundwater pumping on mountain meadows. Quantitative models developed to analyze pumping in mountain valleys and basins must consider the characteristic steep terrain and bedrock outcrops in these watersheds, as well as the limited volume of aquifer sediments and strong seasonality of precipitation inputs.
More than 3 million people visit Yosemite National Park each year, most during the dry summer months. Providing a reliable public water supply for staff and visitors is a critical issue. The California climate produces abundant winter precipitation and nearly rain-less summers in the Sierra Nevada. Most mountain soils dry excessively (Lowry et al., 2011) and most small streams are intermittent during the summer (Lundquist et al., 2005). Thus, surface water supplies are limited and most water for human use in Yosemite National Park is derived from groundwater sources. Some deep groundwater sources are available, such as along the Merced River in Yosemite Valley, while others are from shallow aquifers. One such shallow aquifer is located at Crane Flat, an important visitor services area that supports a large wet meadow and fen complex important for foraging bears, deer, Great Gray Owls and other wildlife. A single production well was installed in Crane Flat meadow in 1984 and provides water for a campground, gas station, residences, and an environmental campus. The well was drilled 122m deep, with the intention of drawing water from a deep bedrock aquifer, and the influence of pumping on the meadow Epigenetics Compound Library was assumed to be minimal.

Study area
Crane Flat is a 20ha meadow complex, located at 37°45′16″N and 119°48′9″W, in the west-central portion of Yosemite National Park, California, USA (Fig. 1). Its watershed area is 75.7ha. Land surface elevations at Crane Flat range from 1870 to 1890m above mean sea level (m amsl). The underlying watershed bedrock is igneous intrusive Arch Rock Granodiorite and El Capitan Granite, with the metamorphic Pilot Ridge Quartzite outcropping on the northwest side of the study area. A surface layer of peat 10–140cm thick covers 0.5ha of the meadow. Most of this area is a fen (Fig. 1) that we define as a groundwater-supported wetland with 20–40 or more cm of organic soil. The peat is underlain by mineral sediments comprised of sand- and gravel-sized particles. This material is a mixture of weathered bedrock, glacial till, and colluvium derived from adjacent slopes. The sand and gravel sediments are over 10m thick in this area. Other portions of Crane Flat are wet meadows with mineral soil. During mid- to late-summer the organic soils are cracked and uneven with patchy vegetation suggesting oxidation and subsidence (Leifeld et al., 2011). Upland areas support conifer forest dominated by white fir (Abies concolor), sugar pine (Pinus lambertiana), and lodgepole pine (Pinus contorta).
The sand and gravel sediments are the primary near-surface aquifer unit at Crane Flat. High water levels in the fen are produced by convergent groundwater flow paths originating from two areas. Springs that emerge from faults in the metamorphic bedrock from the west arm springs (shown on Fig. 1) provide a source of water that locally recharges the aquifer in the western portion of the study area. Inflow from valley sediments to the north represents the other major source of groundwater inflow to the fen. In addition to these two main inflows, the Epigenetics Compound Library aquifer is recharged directly by precipitation (primarily snowmelt) throughout the meadow. Intermittent surface water flow does occur during snowmelt. The surface flows are characterized by low velocity, occurring over a rough vegetated surface, and are generally not contained within well-defined channels. During wet years, intermittent surface water is observed between April and late June. However, saturated conditions at the fen are not dependent on surface water inflow.