Annual Variation in the Dynamics of a Woodland Plant Community

The dynamics of a Pinyon Pine-Utah Juniper woodlands community were studied to determine the baseline conditions and the annual variation in the major plant components. Understanding the normal baseline community status and its annual variation is paramount to evaluating the possible impact of an air pollutant on the system. Environmental impact assessments rarely concern data from more than one or two years, yet results of the present study show that annual variation is such that data from several years are necessary to establish a valid baseline for community structure.