4. Population Ecology

1. Core Content:

• Population Size Immigration, emigration, mortality, births. Fluctuations. Limiting factors and carrying capacity. Logistic and geometric growth curves with phases.

• Interactions in the Environment

- predation: two South African examples of predator- prey relationships: graphs;

- competition: interspecific: for light, space, water, shelter and food; intraspecific: for food, access to mates, water, space, and shelter; survival is determined by access to the above, ecological niches;

- specialisation: competitive exclusion and resource partitioning; discuss one example of coexistence in animals and one example in plants;

- parasitism: two examples from South Africa; one species benefits

- mutualism: two examples from South Africa; both species benefit;

- commensalism: two examples from South Africa.

• Social Organisation: The benefits of herds/flocks (avoidance); packs (hunting); dominance; and the division of tasks (castes) (mention only).

• Community change over time: Succession Primary and secondary succession and possible endpoints depending on environmental fluctuations (mention only).

• Human Population Reasons for exponential growth: - age and gender distributions for different countries, including South Africa; - forecast of South Africa’s population growth over the next twenty years and predict possible consequences for the environment.