Answer:
pH is the measure of hydrogen ion concentration in a solution. It measures how acidic or how basic a solution is, on a scale of 0 to 14, where less than 7 is acidic, 7 is neutral, and greater than 7 is basic.
Species abundance is the number of individuals per species, and relative abundance refers to the evenness of distribution of individuals among species in a community. Two communities may be equally rich in species but differ in relative abundance