Species & Populations (DP IB Environmental Systems & Societies (ESS): SL)

Outline the role of abiotic factors and how they influence ecosystems, providing examples to illustrate their impact.

Outline the role of biotic factors and how they influence ecosystems, providing examples to illustrate their impact.

With reference to a named species, distinguish between the terms habitat and niche.

Distinguish between the terms fundamental niche and realised niche.

Compare and contrast predation and competition.

i)

Define the term carrying capacity.

[1]

ii)

Outline four factors that contribute to the difficulty in estimating carrying capacity. At least two of these factors should be specific to human populations

[4]

The figure below shows how the dominant vegetation changes with altitude in the Alps mountain range in Europe.

Identify three limiting factors likely to be affecting alpine vegetation above 2 500 m.

Explain the role of limiting factors in shaping S and J population curves.

When plotted on a graph, the population growth of a particular population often takes on an 'S' shape, sometimes known as an S-population curve.

Explain how the interactions that a species has with its environment can result in this curve.

Discuss the role of carrying capacity in determining population size in humans and other species.