Relationship between Cutler Mormon-Tea [Ephedra cutleri] and Coppice Dunes in Determining Range Trend in Northeastern Arizona

Abstract

Range trend is one of the basic components of rangeland inventories. Understanding the interactions between soil, climatic factors, and vegetation aids the range manager in determining and predicting trend. Coppice dunes, dune interspace, and vegetation were evaluated in northeastern Arizona. Soil with a surface layer of loamy fine sand is susceptible to wind erosion. If Cutler Mormontea is part of the plant community, coppice dunes may form. Range trend can be determined and predicted by observing the status of the coppice dunes, the dune interspace, and their vegetation. Range managers make inventories that are used to develop quality range management plans. Range condition and trend are two basic components of the inventory. Range condition is the present state of vegetation in relation to the natural potential plant community for the site. Range trend is a determination of the direction of change in range condition or what is currently happening to the plant community. Interactions between soil and vegetation are important in understanding range trend. If the range manager can understand the cause of soil movement and the reaction of vegetation, current range trend can be better determined and gross trend changes can be predicted. Many rangelands in low precipitation areas are unable to support a complete plant cover. Bare ground is natural and provides a source for some local soil movement. However, any decreases in plant cover will accelerate soil surface movement. The purpose of this study was to evaluate the soil and vegetation on coppice dunes and dune interspaces in order to understand how the dunes and vegetation might be related to current range trend and gross trend changes.