Dry Riparian Communities

2/26/12

dry wash

     A riparian zone is an area along banks of rivers, shoreline, marshes, and lakes where distinctive plants and animals live.  The word riparian is derived from the Latin ripa, meaning river bank.  Desert ecologists broaden the concept of riparian zones to include banks of dry washes in the desert calling them "dry" riparian habitats, as opposed to "wet" riparian habitats.

     In my area of the Sonoran desert, these dry washes occupy less than five percent of the area, but they are the most productive ecosystems in the desert.

Abert's Towhee

      Riparian vegetation provides food for a variety of animals, and provides refuge from heat and drought, especially for animals crossing the barren stretches of the surrounding desert.  The Sonoran desert dry washes support ninety percent of the desert's bird life, including not only birds that live there, such as Abert's Towhee, and Least Bell's Vireo, but also migrating bird populations.

Desert Willow tree

     The washes also support a woodland of  Desert Willow, Ironwood, and Cottonwood trees, as well as animals such as the Gray fox, Harris' Antelope squirrel, and Whitethroat woodrat.

Gray fox

     This concentration of plants and animals, that would otherwise not occur in the area, is the result of the availability of water, even though the wash may carry water for only a few hours or days a year.

     Unfortunately,  ninety percent of Arizona's riparian areas, the richest arid landscapes in the desert,  have been lost in the last century because of urban and rural development, crop production, mining, air and water pollution, and droughts.