Local factors in ecological development and change (such as agriculture,…

The idea

Local ecosystems are dynamic, with their development heavily influenced by human-driven local factors. Agriculture alters ecosystems through monoculture and fertilisers, leading to eutrophication and a loss of native biodiversity. Urban change drives habitat fragmentation, forcing species to adapt or migrate. The planned introduction of new species, such as planting non-native conifers for forestry, deliberately alters the ecological balance and soil chemistry. Meanwhile, the unplanned introduction of invasive species, like the accidental arrival of zebra mussels or the oak processionary moth, often outcompetes native flora and fauna, disrupting established food webs and changing the ecosystem's developmental trajectory.

What earns the marks

• Explain how agricultural practices, such as fertiliser use or hedgerow removal, alter local ecological development.
• Assess the impact of urban change, including habitat fragmentation and pollution, on local biodiversity and ecosystem structure.
• Distinguish between the planned introduction of species for agriculture or landscaping and their subsequent ecological consequences.
• Analyse the disruptive effects of the unplanned introduction of invasive species on native food webs and habitat stability.

Common mistakes and how to put them right

• Treating all species introductions as accidental or negative.

  Put it right: Distinguish between planned introductions, like agricultural crops or forestry, and unplanned invasive species, noting the specific impacts of each.

• Discussing global factors like climate change when the question specifically asks for local factors.

  Put it right: Focus strictly on local drivers such as nearby urban expansion, local farming practices, or specific local species introductions.

• Failing to explain the mechanism of change, simply stating that agriculture destroys ecosystems.

  Put it right: Detail the specific processes, such as how fertiliser runoff causes eutrophication or how monocultures reduce genetic diversity.

Exam tips

• Prepare a detailed case study of a local ecosystem that clearly demonstrates the impacts of agriculture, urbanisation, and species introduction.
• Use specific terminology like 'habitat fragmentation', 'eutrophication', and 'invasive species' to elevate the geographical quality of your answer.
• Compare the relative severity of different local factors, evaluating whether urban change or agricultural expansion has a greater impact on your chosen ecosystem.