Population diversity is the second level in the diversity hierarch immediately above genetic diversity and below species diversity. It is revealed through variation in characteristics among individuals that form the population. The modular structure of plants contrasts with the unitary structure of animals and leads to a need for a clear definition of the plant individuals. Developmental stages and age classes are common components of structural diversity that should vary in healthy plant populations. Data regarding these components are gathered with techniques that ensure that the fate and reproduction of each individual plant is maintained. Techniques such as population viability analysis use measures of the probability of individuals progressing from one stage or age to another stage or age. When these measures are obtained under differing management objectives they can be used to project the vulnerability of the population to management options. Examples are presented that demonstrate the risk of a population explosion of a cheatgrass population and the risk of extinction for bluebunch wheatgrass under two grazing systems.
Pyke, David A.
"Population diversity with special reference to rangeland plants,"
Natural Resources and Environmental Issues: Vol. 4
, Article 4.
Available at: http://digitalcommons.usu.edu/nrei/vol4/iss1/4