Permanent Quadrats

Edexcel A-level BiologyThe Nature of EcosystemsLesson 34 of 39

A permanent quadrat is a sampling area that is marked out and left in place, often with pegs or posts at its corners, so that exactly the same area can be sampled again and again. Its position is also recorded with a map, GPS or measurements from fixed landmarks.

Permanent quadrats are used to study how a community changes over time, for example:
- succession on bare ground, a sand dune or an abandoned field
- recovery after a fire, flood or pollution incident
- the effects of management such as grazing, mowing or coppicing
- the effects of climate change over many years

Because the same area is measured each time, differences between surveys are due to real change rather than to sampling a different patch. This removes a major source of variation.

More in The Nature of Ecosystems

• Ecological Techniques
• Quadrats
• ACFOR Scale
• Point Quadrats
• Transects
• More Ecological Techniques
• Hypothesis Testing
• Spearman's Rank Correlation Coefficient

All 39 lessons in The Nature of Ecosystems · All Edexcel A-level Biology topics