, 2011 and Loheide et al., 2009). Meadows

provide vital ecosystem services by maintaining the biotic and geochemical integrity of mountain watersheds. They are critical habitat for many plant (Hajkova et al., 2006 and Jimenez-Alfaro et al., 2012) and animal (Semlitsch, 2000) species, support regional biodiversity (Stohlgren et al., 1998, Hatfield and LeBuhn, 2007, Flinn et al., 2008 and Holmquist et al., 2011), form carbon-rich soils (Chimner and Cooper, 2003), and filter water by storing or transforming mineral sediment and nutrients (Hill, 1996, Knox et al., 2008 and Norton et al., 2011). In most mountain regions in the temperate zone meadows cover less than 2% of the landscape, and their persistence is threatened by human activities such as road building and logging that can increase sediment isocitrate dehydrogenase inhibitor review fluxes, overgrazing by domestic livestock that buy EPZ-6438 can alter meadow vegetation and cause soil erosion, and dams, diversions, channel incision, ditching and groundwater pumping that alters meadow hydrologic regimes (Patterson and Cooper, 2007, Loheide and Gorelick, 2007 and Chimner et al., 2010). The effect of hydrologic alteration on meadows is poorly understood, however hydrologic changes are often identified as the main cause of conifer tree invasion into meadows (Jakubos and Romme, 1993 and Vale, 1981). Several ecological processes maintain mountain meadows in their treeless

state, including seasonally or perennially high water tables and highly productive vegetation (Lowry et al., 2011), climate and landform (Jakubos and Romme, 1993 and Zald et al., 2012), fire regime (Norman and Taylor, 2005), and herbivory (Manson et al., 2001). In the Sierra Nevada of California many mountain meadows receive sufficient groundwater inflow to maintain areas of surface soil

saturation throughout the nearly precipitation-free growing season (Cooper and Wolf, 2006). Two main types of mountain meadows occur in western North America: wet meadows that have seasonal saturation in the root zone, and fens that are perennially saturated (Cooper et al., 2012). Organic matter production and decomposition are nearly equal in wet meadows, which limits organic matter accumulation in soils. Fens form where the rate of organic matter production exceeds the rate of decomposition either due to waterlogging, allowing partially decomposed plant matter to accumulate over millennia, forming organic, or peat soils (Moore and Bellamy, 1974). Fens support a large number of plant, amphibian and aquatic invertebrate species that rely on permanent water availability. They are uncommon in steep mountain landscapes because slopes are excessively well drained (Patterson and Cooper, 2007). However, where hillslope aquifers recharged by snowmelt water support sites of perennial groundwater discharge, fens have formed (Benedict, 1982).