Ecological Characteristics of Riparian Washes in Southeastern Arizona, USA

• Published in: Natural areas journal 2000-07, Vol.20 (3), p.221-226
• Main Authors: Harris, Lisa K., Ruther, Sherry
• Format: Article
• Language: English
• Subjects: Arizona; Canyons; Conservation biology; Conservation of resources; Ecology; Environmental policy; Human ecology; Natural resources conservation; Nature conservation; Plants; Riparian areas; Riparian ecology; Synecology; United States; USA, Arizona; Vegetation
• ISSN: 0885-8608; 2162-4399

We describe the efforts of one southeastern Arizona community that incorporates natural resource conservation and the design of biological linkages and greenways into their planning process. Sierra Vista, Arizona, includes 18 major riparian areas, several of which are connected to large, federally protected natural areas managed by the U.S. Forest Service, Department of Defense, and Bureau of Land Management. The city is located between the Huachuca Mountains and the San Pedro River, and the dominant vegetation community in the undisturbed areas is mixed grass–scrub. We developed a protocol that (1) identified linear riparian resources that connect the large land reserves and (2) aided local planners in establishing linkages to facilitate the community's recreational and open space needs while promoting the retention of biologically valuable areas. Based on aerial photographs and ground truthing, we delineated the location and extent of the riparian areas, characterized their associated vegetation communities, and identified ecologically significant attributes such as connectivity to nearby federally protected land, presence of surface water, presence of multiple vegetation types, and presence of scarce vegetation types. We identified five different vegetation communities and one vegetation type influenced by human-induced disturbances. We categorized each riparian area into one of three priority conservation levels. The most important (level 1 riparian areas) were areas that provided connectivity between the mountains and the river, and supported multiple vegetation types and at least once scarce (measured in hectares) vegetation type. Level 1 riparian areas contained the most valuable ecological attributes and should be considered a top priority during community planning. Level 2 areas were those that contained one or more ecological attributes and are places where it is more appropriate to consider human uses and preservation of biological resources equally when planning. Finally, level 3 areas were washes that failed to display any of the key ecological attributes we selected for this study; while these areas should be afforded protection, they could be developed for passive recreation use or used as undisturbed buffer areas. Of the 18 riparian areas, two were classified as level 1 riparian areas, two were classified as level 2 riparian areas, and the rest were level 3 riparian areas.