PSOW – Practical 2.1H Fundamental and Realized Niches (HL only) with Teacher’s Notes

Description

IB ESS Practical 2.1H: Fundamental and Realized Niches (HL only)

Help HL students understand how competition narrows a species’ niche by working with the published data ecologists used to prove it.

In this practical activity, students choose a named species with published data on both its fundamental and realized niche. Suggested examples include Joseph Connell’s classic barnacle experiments and studies of brown and green anoles. Students then:

• Define the niche: record at least four abiotic or biotic parameters and the range of each that the species tolerates without competitors (fundamental niche) and with them (realized niche)
• Visualize the difference: draw the two ranges for each parameter as paired bars on a shared axis
• Identify the mechanism: name the competitor responsible for restricting the realized niche and describe how the restriction happens

The activity then connects niches to classification. Students locate a cladogram that includes their species and its competitor, identify their most recent common ancestor, and find a point where the cladogram disagrees with traditional taxonomy. Finally, they identify a human impact that could change the realized niche and predict the direction of change.

IB ESS Internal Assessment Skills

This activity is assessed using IB ESS Internal Assessment Criteria D: Treatment of Data and E: Analysis and Conclusion, and the full rubrics are included. Students must:

• Present the fundamental and realized ranges for every parameter and explain how they extracted each range from the published data
• Analyze the difference between the two niches and the competitive mechanism, including the uncertainty of relying on a single published study
• Draw a conclusion about the advantages of classifying organisms by clade, supported by the disagreement they identified

The activity builds skills students need for secondary-data IAs: extracting values from published figures, citing sources traceably, and recognizing the limits of a single study. The teacher’s notes explain why Connell’s work is the ideal example, since its removal experiment shows the realized niche expanding once the competitor is gone.

Ideal for

• Teaching fundamental and realized niches
• Teaching interspecific competition
• Using Connell’s barnacle experiments
• Introducing cladograms and cladistics
• Comparing clades with traditional taxonomy
• Working with published scientific data
• HL ESS classes
• Preparing students for the IB ESS Internal Assessment

Digital download. No physical product will be shipped.