Haberkorn, Matt; Phoenix College Bioscience Department, Phoenix, AZ (Arizona-Nevada Academy of Science, 2015-04-18)
      Ephemeral drainage plant communities of the Sonoran Desert compose a highly significant yet relatively unexplained portion of the ecosystem. Eighty-one percent of all southwestern and 94% of Arizona drainages are categorized as ephemeral drainages (Levick et al. 2008). Small but significant portions of the bajada environment are also composed of ephemeral drainages. These drainages carry out important landscape scale functions in water movement, groundwater recharge, nutrient movement and cycling, sediment transportation, geomorphology, plant habitat, seed disbursement, as well as wildlife habitat and corridors. In decades past, Sonoran Desert bajada research relating the physical earth sciences to ecology has focused on explaining upland plant community patterns along this landform (Yang and Lowe 1956, Phillips and MacMahan 1978, Key et al. 1984, McAuliffe 1994, Parker 1995, McAuliffe 1999). This body of research, however, has very little information pertaining to ephemeral drainages dissecting the upland bajada environment. The bajada geomorphic environment is a composition of geomorphic surfaces of varying soil development proceeding away from a mountain (Peterson 1981, McAuliffe 1994). Each of these geomorphic surfaces is characterized by a unique lithology, slope, age and degree of argillic and caliche soil horizon development. Generally, geomorphic surfaces containing highly developed argillic or caliche soil horizons are found near the mountain while surfaces of undeveloped soils are furthest away from the mountain. Depending on the bajada, local geomorphic history, however, may result in different landscape scale patterns of geomorphic surfaces and soil development. This physical environment forms the template from which the ephemeral drainage develops its channel morphology, hydrology and botanical associations. It was expected that the various geomorphic surfaces composing the bajada found at the study sites would determine the specific channel morphology, hydrology and plant community associations of the examined ephemeral drainage. The goal of this study was to explain (1) channel morphology, (2) hydrology or ephemeral flow patterns and (3) plant communities found along the ephemeral drainage. Plant communities of drainages were also compared to upland communities. These factors were then utilized to give an overall explanation for the distribution of hydrogeomorphic and botanical associations found along the bajada ephemeral drainage.

      Jemison, Roy; U.S. Forest Service, Southwestern Region, Albuquerque, NM (Arizona-Nevada Academy of Science, 2015-04-18)
      The USDA Forest Service Southwestern Region (FS) manages over 20.5 million acres of forests and grasslands in Arizona, New Mexico and the Texas and Oklahoma panhandles. Water is one of the most beneficial natural resources used on and off these lands by humans, animals and plants. Water on forest and grasslands generally comes from precipitation which arrives in the form of snow or rain, depending on the location and season. On the ground, water infiltrates, ponds, runs off or evaporates, depending on the surface and climatic conditions. In general, precipitation that falls on these lands is free of pollutants. As water moves across and through soils, rocks and other materials it can become polluted by the surfaces it comes in contact with and by materials added to it. Materials added to flowing water in small amounts over time may have little to no harmful effects on the quality of the water. In large amounts and or concentrated, it can be extremely harmful to the quality of the water and users of the water. Common impacts to water quality include increases in temperature, turbidity, nutrient levels and hazardous chemicals. Sources of pollutants on forests and grasslands can be natural and human introduced. Natural sources and causes of pollution can include soil erosion, wildlife waste, concentrations of naturally occurring materials, drought, and flooding. Human sources and causes of pollution can include runoff from roads, trails, tree harvest areas, recreation sites, sewage facilities, livestock, pesticide applications and fuel and chemical spills (USDA Forest Service 2000). A plethora of methods exist to minimize harmful impacts to water quality on forests and grasslands. In 1990, the FS Southwestern Region developed a core set of practices and procedures, that when properly implemented, can be effective at minimizing and mitigating harmful impacts to water quality. The practices and procedures are both administrative and physical, and are collectively referred to as Soil and Water Conservation Practices, also known as Best Management Practices (BMPs) (USDA Forest Service 1990). Even though these BMPs were designed by FS and state resource specialists in the Southwest, they often require adjustments to make them fit site-specific conditions. The BMPs used by the FS Southwestern Region are acknowledged as being effective control measures by the environment departments of the states (Arizona and New Mexico) in which they were developed, as documented in Memorandum of Understandings (MOUs) that exist between the FS and the states.

      Burke, Megan; Northern Arizona University, Flagstaff, Arizona (Arizona-Nevada Academy of Science, 2015-04-18)
      This paper evaluates the historical growth of the Las Vegas Wash, its subsequent degradation, and the current efforts to restore and stabilize its channel. The Las Vegas Valley Metropolitan Area is located in the Mohave Desert in a drainage basin surrounded by mountain ranges. This drainage basin and its dynamic system of stream channels constitute the Las Vegas Watershed in which the Wash is located. The condition of the Las Vegas Wash is unique, as is a perennial stream that evolved from an ephemeral wash in response to the rapid urbanization and subsequent production of treated wastewater input into the stream channel. The situation has created a series of wetland ecosystems along the Wash, and valuable riparian habitat in such an arid environment. The Wash and its associated wetlands system provide a variety of ecological services to the city of Las Vegas, including storm water conveyance, wastewater effluent filtration, flood protection, and a green space for residents to enjoy. However, continuous increase in volume and intensity of the stream flow has resulted in severe channel degradation and bank erosion in numerous locations along the stream channel. After an examination of the historic and present-day conditions of the Wash and its restoration activities, this essay suggests that future evaluations of the Las Vegas Wash case study may provide evidence to support the propagation of collaborative management efforts.

      Klotz, Jason; Tecle, Aregai; School of Forestry, Northern Arizona University, Flagstaff, AZ (Arizona-Nevada Academy of Science, 2015-04-18)
      This paper is concerned with restoring the quality of water in some portions of the San Pedro River. There are high concentrations of bacteria in some parts of the San Pedro River. Our aim is to find ways of improving the situation. Specifically, there are two objectives in the study. The first one attempts to identify the possible sources of the bacterial contamination and assess its trends within the watershed. The second objective is to determine appropriate methods of restoring the water quality. The main water quality problem is nonpoint source pollution, which enters the stream and moves along with it. The magnitude of the problem is affected by the size and duration of the streamflow, which brings bacteria-laden sediment. The amount of sediment brought into the system is large during the monsoonal events. At this time, the streamflow becomes highly turbid in response to the organic and inorganic sediments entering the system. Based on research done for this paper, the amount of bacterial concentration is strongly related to turbidity. Best management practices (BMPs) have been designed and implemented to restore the water quality problem in the area. The BMP's consist of actions such as monitoring, educational outreach, proper signage, and other range/watershed related improvement practices. Other issues that contribute to the increasing amount of bacteria that are briefly addressed in this paper are bank and gully erosion, flood control, and surface water and streamflow issues that occur on the stream headwaters.

      Fenner, Patti R.; Friends of the Tonto National Forest, Phoenix, AZ (Arizona-Nevada Academy of Science, 2015-04-18)
      Permanent riparian photopoints (repeat photography of streamside points) are a widely used monitoring method for situations where there are many streams to monitor, and little time to do it. They often display dramatic changes in these dynamic ecosystems – changes that are brought about by management of permitted and non-permitted activities, flood, drought, and fire. Most of all, they help us to learn more about the relationship of riparian areas to uplands, and how riparian ecosystems function.

      Gottfried, Gerald J.; Neary, Daniel G.; Emeritus Scientist, U.S. Forest Service, Rocky Mountain Research Station, Phoenix, AZ; Supervisory Soil Scientist, U.S. Forest Service, Rocky Mountain Research Station, Flagstaff, AZ. (Arizona-Nevada Academy of Science, 2015-04-18)
      The availability of adequate and reliable water supplies has always been a critical concern in central Arizona since prehistoric times. The early European settlers in 1868 initially utilized the ancient Hohokam Indian canal system which drew water from the Salt River. However, the river fluctuated with periods of drought and periods of high flows which destroyed the diversion structures. The settlers proposed a dam to store water and to regulate flows. In 1903, the Salt River Water Users Association was formed and an agreement was reached with the U.S. Government for the construction of a dam on the Salt River at its junction with Tonto Creek. The Salt River drains more than 4,306 square miles (mi2) from the White Mountains of eastern Arizona to the confluence with Tonto Creek. Tonto Creek drains a 1,000-mi2 watershed above the confluence. The agreement was authorized under the Reclamation Act of 1902. The Theodore Roosevelt Dam was started in 1905, completed in 1911, and dedicated in 1911 (Salt River Project 2002). The dam has the capacity to store 2.9 million acre-feet (af) of water. However, between 1909 and 1925, 101,000 af of sediment were accumulated behind Roosevelt Dam (Rich 1961). Much of it came from erosion on the granitic soils from the chaparral lands above the reservoir, and much of the erosion was blamed on overgrazing by domestic livestock. Water users were concerned that accelerated sedimentation would eventually compromise the capacity of the dam to hold sufficient water for downstream demands. The Tonto National Forest was originally created to manage the watershed above Roosevelt Dam and to prevent siltation. The Summit Plots, located between Globe, Arizona, and Lake Roosevelt were established in 1925 by the U.S. Department of Agriculture to study the effects of vegetation recovery, mechanical stabilization, and plant cover changes on stormflows and sediment yields from the lower chaparral zone (Rich 1961). The area initially was part of the Crook National Forest which was later added to the Tonto National Forest. The Summit Watersheds consisted of nine small watersheds ranging in size from 0.37 to 1.23 acres (ac). Elevations are between 3,636 and 3,905 feet (ft). The treatments included: exclusion of livestock and seeding grasses, winter grazing, hardware cloth check dams, grubbing brush, sloping gullies and grass seeding. Protection from grazing did not pro duce changes in runoff or sedimentation. Treatments that reduced surface runoff also reduced erosion. Hardware cloth check dams reduce total erosion, and mulch plus grass treatments checked erosion and sediment movement. Runoff was reduced by the combined treatments (Rich 1961). The Summit Watersheds were integrated into the Parker Creek Erosion-Streamflow Station in 1932.

      Kursky, Joshua; Tecle, Aregai; Northern Arizona University, Flagstaff, AZ (Arizona-Nevada Academy of Science, 2015-04-18)
      Hart Prairie is a high-elevation upland riparian ecosystem on the west slope of the San Francisco Peaks in northern Arizona. The location is unique, not only as an upland riparian area in the semi-arid Southwest, but also for having a wet meadow ecosystem dominated by Bebb willow (Salix bebbiana). The ecosystem has experienced a high degree of change since the time of Euro-American settlement. Along with fire suppression, increased wild ungulate herbivory rates, and conifer encroachment into a historically short-grass prairie, several humaninduced changes have been made to the topography of the watershed. Stock tanks, an earthen berm with associated diversion channels, and a road that cuts perpendicularly across the direction of water flow near the base of the watershed have contributed to the altered drainage patterns and the decreased water availability to the flora and fauna in the area. As a result, the Bebb willows and the associated meadow vegetation are at risk. Most of the willows, which constitute the majority of the canopy in the ecosystem, are at a decadent, over-mature stage that allows a limited recruitment of younger plants (Maschinski 1991, Waring 1992). Under these conditions, the plant community may die off leading to the loss of this rare riparian area forever. Research on restoration efforts have been undertaken since the mid-1990s on The Nature Conservancy’s Hart Prairie Preserve and the adjacent US Forest Service Fern Mountain Botanical Area. This paper summarizes the efforts that have been made; most of which targeted to improve the low germination rates of willow seeds, and to restore the geomorphology and surface flow patterns to their pre-disturbance conditions.