Students listen to a 50-minute presentation on how invasive species can affect the population growth of a native species through disease (or disease transmission), competition, and predation.
They then complete a hands-on activity in which carrying capacity is demonstrated using a game with a 10x10 grid and kidney beans.
Students will understand that population growth of native species can be positive or negative, is affected by many different biotic and abiotic factors, and is often affected negatively by invasive species. In the activity, students learn to estimate carrying capacity.
National Science Education Life Science Standards
Grades 5-8: The number of organisms an ecosystem can support depends on the resources available and abiotic factors, such as quantity of light and water, range of temperatures, and soil composition. Given adequate biotic and abiotic resources and no disease or predators, populations (including humans) increase at rapid rates. Lack of resources and other factors, such as predation and climate, limit the growth of populations in specific niches in the ecosystem.
Sunshine state standards
SC.7.L.17.3: Describe and investigate various limiting factors in the local ecosystem and their impact on native populations, including food, shelter, water, space, disease, parasitism, predation, and nesting sites.
Math standards can be applied to this activity.
- The scripted presentation can be downloaded from www.protectingusnow.org.
- Be sure to go over the text ahead of time, tweaking it as you need to for your audience. In addition, all 3 activities are included in the presentation, so be sure to remove the ones you do not wish to do.
- Download and make copies of the student handout “Estimating the Carrying Capacity” from www.protectingusnow.org.
The activity can be found on Page 4 of the PDF linked below.
- You will need several 10in X 10in boxes, three bags of kidney beans, rulers, the grid, and plastic cups for this activity.
- Assemble the boxes, sealing the bottom of the box, but removing the flaps for the top of the box.
- Print as many grids as you have boxes (grid can be downloaded from www.protectingusnow.org). Glue the grids to the bottom of the boxes.
- The grid measures 10in X 10in, so you will need to use a printer that can print the grid to actual size (such as a poster printer). If your school does not have one, a print shop can help you out.