Examples of modular growth in (a) aspen trees, in which root buds give rise to clones, and (b) seagrass, in which new shoots form from rhizomes.

Examples of modular growth in (a) aspen trees, in which root buds give rise to clones, and (b) seagrass, in which new shoots form from rhizomes

Examples of clonal animals: (a) corals and (b) sponges.

Hypothetical population; red dots represent individuals and blue line defines the population distribution

Distribution of moss Tetraphis pellucida at a number of different spatial scales; from its global geographic range to the location of individual colonies on a tree stump.

Abundance: total number of individuals (red dots)Population density: number of individuals per unit area

A metapopulation is made up of small, isolated populations.

Individuals

Habitatpatches

Although some subpopulations go extinct over time...

…migration can restore or establish subpopulations.

(a) Cross-section of a tree trunk showing annual growth rings;(b) Time series of radial increments for an American beech tree

average number of female offspring produced by a female of age x

Gross reproductive rate = average number of female offspring born to a female over her lifetime

mean number of females born in each age group adjusted for survivorship

R0 = net reproductive rate; average number of females that will be left during a lifetime by a newborn female

Effect of population density on the growth of the tadpole Rana tigrina

Number of individuals

Effect of population density on the growth of white clover plants

Grain (seed)production in individual corn plants