Conditions that define a riparian zone in southeastern Arizona

Abstract

Riparian areas in Arizona have been centers for man's activities such as farming, cattle grazing, recreation, wildlife habitat, water, and cities, since the early 1800's. Representing less than one percent of Arizona's land resource base, riparian areas have received a disproportionately high amount of use and abuse. Public and private awareness of the necessity to preserve and manage riparian areas was aroused in the late 1960's by the Arizona Fish and Game Department and United States Forest Service with a study documenting that clearing of riparian areas was detrimental to wildlife habitats. Since the early 1970's national conferences, studies, and legislation concerning protection, preservation, and management of riparian areas have demonstrated the increasing public interest for riparian areas. Proper management of riparian areas requires land managers to have information on the environmental parameters active in these areas. Riparian areas have been studied since the 1930's, but early studies looked mainly at how to increase water yields from riparian areas through vegetation management. It has only been since the 1970's that studies have been aimed at protection and preservation of riparian areas. This dissertation documents an added effort to broaden the existing knowledge on riparian areas in the southwest. A riparian area bordering Paige Creek in southeastern Arizona was monitored for 24 months. Environmental data (e.g. precipitation, streamflow, watertable levels, soils, soil water status, and vegetation) were collected and analyzed with the objective, to determine if soil moisture content could be used as an indicator of a riparian area in the absence of typical riparian vegetation. Statistical tests indicated soil moisture in the upper 48 inches of soil could not be used to indicate the riparian area. The position of existing riparian vegetation was controlled by the location of the watertable. Unless the location of the free water supply is known, soil moisture readings alone could prove misleading.