Community ecology, biodiversity and disruptions to ecosystems

Learning objectives

Describe competition, predation, parasitism, mutualism and commensalism, and explain how each affects the population sizes of the species involved

Explain how species diversity and richness contribute to the resilience of an ecosystem, and calculate a simple index of diversity from species count data

Describe how matter cycles through ecosystems in the carbon, nitrogen, phosphorus and water cycles, and contrast this cycling of matter with the one-way flow of energy

Explain how invasive species, habitat loss, human land use and climate change disrupt ecosystems, and predict the knock-on effects on other populations in a food web

Explain why the geological and biological record shows that ecosystems change over time, and use data to justify a claim about the cause of an observed change in a community