Population change can occur through variation in the
number of populations for a given species, the number of
individuals per population, the spatial distribution of
populations, and the genetic differentiation within and
among populations. Historically, the term ‘population
diversity’ has largely been used by geneticists when
discussing genetic differentiation (e.g., [14–16]), or as a
measure of the number of Mendelian populations in a
given area [6]. These approaches are limited because
they ignore important demographic characteristics of
populations that can influence the provision of ecosystem
services. We argue that assessments of population
diversity should consider both the demographic
(e.g. size, number and distribution) and genetic nature
of populations.