Riparian Vegetation of the Northern Range, Yellowstone National Park; Classification, Succession and Environmental Relationships

Abstract

For many years interest in and research concerning wetlands has lagged behind the more extensive efforts put furth in upland and aquatic ecosystems. Recent years have seen wetlands featured in several symposia (Johnson and Jones 1977; Johnson and others 1985; Ratliff 1985; Brosz and Rodgers 1986). Within the Greater Yellowstone Ecosystem and contiguous areas several studies both intensive (Norton, et al 1981; Tuhy 1981; Mattson 1982; Mutz and Queiroz 1983)and extensive (Tuhy and Jensen 1982; Youngblood, et a1 1985; Pierce and Johnson 1986) have been completed. The climate of northern Yellowstone is a hybrid between continental and inland maritime. There is a gradient in precipitation and temperature between the lowest recording station Gardiner (1616 m) and the Northeast Entrance station (2244 m). Gardiner, by virtue of its low elevation, is the warmest and driest location with only 277 mm mean annual precipitation, of which most occurs in the late spring-early summer. The Northeast Entrance, the highest reporting station in this Northern portion of the park, is the wettest (670 mm) and coldest. However, precipitation at the Northeast Entrance is more evenly distributed throughout the year with distinct peaks in early summer and mid winter. Of potentially greater importance than climate to understanding wetland composition is water chemistry. Streams originating to the east of the study area in the Absaroka Range drain predominately extrusive igneous (andesitic) rock and glacial till. Streams originating to the south of the study area drain oligotrophic tephra and rhyolitic substrates. To the west and north a mix of sedimentary and glacial till substrates are represented. Groundwater from these distinct geologic substrates, in addition to water from unique thermal features producing a complexity of groundwater environments in this "northern range".