Barnacle Competition on a Rocky Shore

Assign the fungus sheet to review relationship types, then the barnacle sheet for a paired bar graph. Compare how each study used a control.

Make a paired bar graph from Connell's barnacle study on the Isle of Cumbrae and explain competition. The directions on the page read: Read the text and table. Make a paired bar graph: draw a striped bar with Balanus and a solid bar with Balanus removed at each height. An answer key is included.

Yes, both. We made it for 8th grade ecosystems, and it works the same at home or at school. At home, a student can work through it alone and then go over it with you, which shows quickly what is solid and what needs another look. In class it works as independent practice, homework or a warm-up, and you can print one copy or a full set.

Thin fungus threads grow into the roots and spread through the soil, gathering phosphorus and water the roots cannot reach. The plant feeds the fungus sugar in return. Because both gain, it is mutualism.

Where the larger Balanus grew, it crowded out Chthamalus by growing over it, crushing it or prying it off the rock. Balanus could not live high on the shore because it dried out at low tide. Removing Balanus raised Chthamalus survival on the lower rocks.

Subtract the shorter height from the taller one, divide by the shorter height and multiply by 100. The root fungus sheet asks for this at week 12. Students show their work on the lines.