A catchment-scale approach to the connection between the terrestrial environment and aquatic ecosystems is important because of the context that it provides into stream form and function. A streams physical and chemical qualities are often delineated, in large part, by the surrounding catchment's terrestrial properties and features, such as geology, soils, vegetation and topography (Van Horn et al. 2012). For example, losses in catchment vegetation can result in a change in terrestrial organic carbon inputs into streams (Bunn et al. 1999). Four important dimensions of connection exist when describing the physical, chemical, and energetic interactions between the stream itself and its surrounding catchment: 1) Longitudinal interactions that connect upstream and downstream, 2) lateral interactions which connect the terrestrial, riparian and aquatic portions of the catchment, 3) vertical interactions connecting groundwater and surface water, and 4) a temporal dimension, meaning these interactions are subject to a change in magnitude and scale over time on a catchment by catchment and stream by stream basis (Stanford et al. 2005). Abiotic reach-scale stream traits, like nutrient cycling rates and stream geomorphology, coupled with in-stream and riparian biota, are heavily influenced by local catchment characteristics including parent geology, soil chemistry, and both natural and anthropogenic disturbance regimes (Van Horn et al. 2012). Ungulate grazing, for example, is a disturbance that can change in intensity both spatially and temporally, and have varying impacts on watershed dynamics (Nipper et al. 2013, Laine et al. 2015). Similarly, human activity and land-use practices, such as cattle grazing, can alter a watershed as well. Impacts can include physical and chemical effects to streams (Beschta et al. 2013, Hough-Snee et al. 2013, Batchelor et al. 2015). In the United States, nearly one million square kilometers of public land are used for livestock grazing (Batchelor et al. 2015). Included in this statistic is nearly 80% of the land under control by the Bureau of Land Management and 60% of land controlled by United States Forest Service (Batchelor et al. 2015). Livestock grazing on managed lands tend to convene in and around riparian areas, because of accessibility to water, as well as the availability of riparian forage (Kovalchik and Elmore 1992).
catchment, ungulate exclosures, Valles Caldera
Kelly, Ryan. "Assessing the geomorphological effects of ungulate exclosures on high elevation streams in the Valles Caldera National Preserve, New Mexico." (2016). http://digitalrepository.unm.edu/wr_sp/12