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A lightweight aluminum photograph stand has been developed to record vegetation in permanent plots. At a camera height of 7 m the plot size is 14 m* when using a 70 mm camera with an 80 mm lens. Minor errors were detected when testing the accuracy of the stand. This stand will be useful for obtaining a record of permanent plots for many different types of research studies. Measurements of successional change, or vegetation trend, are difficult to quantify and easy to misinterpret. Trend is usually estimated using such variables as phytomass, cover or frequency. Major changes in the plant community can occur before any of these variables could detect it (Gardiner and Norton 1983, West 1983). Replacement of one species by another (succession), and the births and deaths of individuals, can easily be detected by sampling permanent plots at regular intervals. With such data, the population dynamics of a species can be estimated, and interpretations of range trends are enhanced. Unfortunately, the two most common techniques available for obtaining such data, the pantograph and chart mapping, are time consuming and often inaccurate. Very few plots are recorded and they are typically only 1 m* in area. In semiarid rangelands, the small sample size and limited area covered are usually inadequate for reliable records of changes in most species. One notable exception is the data set collected on 9.3 rnz chart-quadrats at the Desert Experimental Range, Utah (Norton 1978). Other techniques for sampling permanent plots are therefore necessary. Low level aerial photography (Hacker 1978) provides a possible mapping alternative. Many problems, however are associated with small-scale format: different scales due to different aircraft altitudes and uncontrolled distortions caused by aircraft tilt, wind, and site slope. Maps produced in this manner may not be suffiAuthors were principal research technician, graduate research assistant and associate professor, respectively, with the Range Science Department, Utah State University, Logan, Utah 84322 at the time of the research. H.G. Gardiner’s current address is Agricultural Advisor, Rangeland Management Branch, Western Australian Department of Agriculture, Jarrah Rd., South Perth, W.A. 6151. Manuscript accepted September 9, 1984. JOIJRNAL OF RANGE MANAGEMENT 38(3). May 1985 ciently reliable for demographic studies and are generally restricted to low shrublands. Tree canopy cover may obscure essential components of the vegetation, and small individuals, particularly seedlings, are difficult to map accurately. The typical result of sequential recordings of a single plot are assorted photographs of different scales and clarity. Another possibility is to use a stand to hold a camera for groundlevel photography. Cooper (1924) reported devising an oak stand that would hold a 5 X 7 camera 1.8 m above the ground. Unfortunately, the plot accommodated by this stand was only 1 m2. Modifications were made throughout subsequent years to either raise or lower the camera height. Camera height has ranged from a low of 1.2 m (Ratliff and Westfall 1973) to a high of 3.5 m (Goodwin and Walker 1972). Corresponding plot sizes ranged from 0.09 m* to 14 m*, respectively. Only in one photographic method has plot size been sufficiently large to study semiarid vegetation. Goodwin and Walker (1972) developed a photograph standing using a boom rather than the traditional tripod. The camera could be raised to a much greater height, approximately 3.5 m. Using a wide angle lens on a 35 mm camera resulted in a large plot size, but the 35 mm format limits the clarity of the photograph. The Photograph Stand Constructed from lightweight box aluminum, a portable stand has been developed for use in semiarid rangelands (Fig. 1). Using a boom apparatus rather than a tripod allows the camera height above ground to be increased to as much as 7 m. At the maximum height a 3.5 X 4 m plot is obtained. A plot of this size (14 m*) is adequate for studying most semiarid grass and shrub species populations. In order to consistently re-photograph the same plot, anchor pins were necessary. Three pieces of 1.2 m long 15.8 mm concrete reinforcing bar were driven into the ground at every plot. Guide holes in the frame fit over the anchors so the base position is identical at each sampling time. Slight irregularities of the soil

A Photographic Technique for Repeated Mapping of Rangeland Plant Populations in Permanent Plots