Distribution

Ecologists investigate both its abundance — how many individuals there are — and its distribution — where they occur. Two areas could contain similar numbers of daisies but have different distributions: daisies might be spread throughout one area and concentrated in patches in the other.

Environmental changes can affect both population size and distribution. Population size means the number of organisms; distribution means where they occur. A change can increase the population of one species while decreasing that of another, so a community does not necessarily respond as a single unit.