PHYSICAL, BIOLOGICAL AND CULTURAL INVENTORY AND CLASSIFICATION OF NATIONAL PARK SERVICE SPRINGS ON THE COLORADO PLATEAU

In 2005, 75 springs were inventoried and classified in 26 units of the National Park Service for the Northern and Southern Colorado Plateau Inventory and Monitoring Networks. The inventories included site descriptions, environmental and climate conditions, vegetation and invertebrate surveys, wildlife observations, water-quality analyses, geomorphology descriptions, and water-quantity measurements. Spring discharge was less than 1.0 liter/second or immeasurable at 65 % of the springs. Almost all (90 %) of the springs discharged from sedimentary rocks and sandstone was the rock type of nearly ½ of the springs. Most of the spring waters are of a Calcium-sodium/Bicarbonate-chloride-sulfate type, although some of the springs had a much different type of water. There were a total of 633 plant taxa on 157 geomorphic surfaces adding more than 150 plant specimens to the various park herbaria, including more than two dozen previously undetected species in cooperating parks. Average total plant species richness at the springs inventoried was 44.1 (1 sd = 24.58) species/site, a value that is relatively high for southwestern landscapes. Average springs area surveyed was 0.147 ha but highly variable (1 sd = 0.221). The largest springs had the most plant species; however, species richness also varied by geomorphic setting (sloping bedrock surfaces and backwalls had fewer species than channel terraces and colluvial slopes), and by elevation. That total springs diversity varies non-linearly with elevation, with greatest species diversity at intermediate Colorado Plateau elevations (1500-2500 m). We detected and identified more than 8,000 invertebrates at least to the level of taxonomic order, including many new records of aquatic and terrestrial species for the cooperating parks. Invertebrate diversity is strongly related to plant diversity (p<0.001). Either natural or anthropogenic disturbances occurred at 77 % of the springs. Although 9 different types of sphere of occurrence were observed, 60 % of the springs were classified as either hanging gardens or hillslope springs. Only one, each, mound-form, gushet, or hypocrene spring was classified.