Abundance coefficients, a new method for measuring microorganism relative abundance

A new method of measuring the relative abundance of microorganisms by using a set of interrelated coefficients, termed abundance coefficients or AC, is proposed. These coefficients provide a means of recording abundance for geometric density categories, and each density measurement represents an approximation of the Poisson parametert. The AC is the natural logarithm of a characteristic value, which is a particular number for each geometric density category. The characteristic values are based upon a probabilistic error statement derived from the Poisson formula, and they present evidence for separation of the geometric category boundaries bye = 2.71828. The proposed AC provide a means for recording species abundance in a manner suitable for arithmetic manipulation, for population structure studies, and for the determination of practical limits for defining the presence or absence of a species. Further, these coefficients provide for both intrasample and intersample abundance comparisons.