Ecological Site Descriptions: Consideration for Riparian Systems

Abstract

Ecological sites, and the previous iteration known as range sites, have provided ecologically based guidance in making land management decisions for more than 60 years.1 However, previous site description approaches failed to suffi ciently describe the specifi c functions and processes unique to riparian areas, subunits critical to landscape function. Riparian areas are defi ned as the transition zone between the uplands where there is seldom standing water and the stream, lake, or spring where free-fl owing or standing water supports a suite of water-loving plants such as sedges, rushes, and willows.2 Riparian zones in the western United States occupy only a small proportion of the total landscape and are often narrow corridors associated with streams. In spite of this limited area, about 80% of the terrestrial wildlife species known to occur in southeastern Oregon, for example, are dependent on these ecosystems for some portion of their life cycle.3 Riparian zones and meadows have also been found to provide a high proportion of summer forage for livestock and big game.2 The importance of riparian areas to wildlife, livestock, fi sheries, and water quality is well recognized, but the development of riparian ecological sites and the associated state-and-transition models (STMs) is a recent phenomenon.