Development of a Community Index of Minimum Fluctuation for Early Detection of Sulfur Dioxide Perturbation. Final Report, July 1, 1977-November 30, 1982

摘要

This project attempted to develop a method, based on analysis of plant community structure and dynamics, to detect at the earliest stage, any impact or perturbation from sulfur dioxide pollution. Numerous mathematical and statistical approaches were applied, utilizing a 10 year data base in a pinyon-juniper plant community, to reduce the amount of background noise. Analytical procedures included comparing the annual frequency and cover status, ratios of specific frequency and cover to various parameters including prevalent species, diversity index relations, biomass and growth increments, and their ratios to other components, environmental interactions, especially the relations of precipitation and SO sub 2 to frequency and cover variation, and cluster dendrograms and similarity matrices. Community dynamics varied greatly among years, and we found that at least three years' data are essential to obtain a valid baseline. Any fewer provide misleading data. Precipitation was the primary parameter responsible for variation. Analytically, variation was minimized by using a cluster analysis and similarity matrix approach. Variation was further reduced by applying these results to utilizing only the more similar, and representative study plots. Combining these methods provided a workable index from which a minimum fluctuation could provide an early means of detecting community perturbation from an air pollutant stress, in this case, SO sub 2 . (ERA citation 08:006045)