EVALUATION OF 5 METHODS FOR MEASURING DESERT VEGETATION

We obtained a complete census of vegetation in a 30- x 1,900-m plot in the Sonoran Desert (Tumamoc Hill, Pima County, Ariz.). We then evalua ted the accuracy of 5 sampling techniques commonly used to sample vege tation in deserts: step-point, point-quarter, and 3 line-intercept met hods, We compared presence and percent occurrence for each method with the census, The line-intercept (method 3) most closely estimated the census: it was closer for all species occurring on >1% of the site, re vealed the least variability relative to sample size for dominant spec ies, and accounted for more (20 of 23) plant species on the study site than the other methods.