Describe and explain 'S' and 'J' population growth curves. Explanations should be given for changes in both numbers and rates of growth in standard 'S' and 'Y population curves. Population curves should be sketched, described, interpreted and constructed from given data. Both factors may operate on a population. Internal factors might include density dependent fertility or size of breeding territory and external factors might include predation or disease.
Species employing r-strategies achieve a high specific growth rate.
By investing very little in a large number of offspring, although mortality rates tend to be high early in the lifespan, sufficient survive through to sexual maturity. Species employing K-strategies have been selected for competitive superiority at or near the carrying capacity. Much parental investment in each offspring results in low numbers but ensures low mortality rates early in lifespan and so sufficient survive through to sexual maturity. Students should be familiar with interpreting features of survivorship curves including logarithmic scales. Describe the concept and processes of succession in a named habitat.