Students may use the model to explore the interactions among bark beetles, host trees and a few environmental factors. Collect and interpret the gathered data, construct explanations and engage in argument from the evidence to make sense of the changes and stability in a forest ecosystem.
Grades: 6-8;
Choose the forest size and factor conditions.
Choose how long to run the model.
Run the model.
Observe the changes in bark beetles and forests over time.
Bark beetles
Spruce trees
Non-spruce trees
Temperature
Drought
Tree Diversity
Bark beetles use spruce trees as food and shelter.
Bark beetles produce offspring and then die.
They only attack big spruce trees. When a spruce tree is attacked by many beetles, it turns orange and eventually dies.
New spruce trees grow up every year.
When the temperature rises, bark beetles develop faster and may produce more than once. Fewer beetle larvae die in a warmer winter.
When drought becomes severer, it takes fewer beetles to kill a host spruce tree. No relationships are defined between temperature and severity of drought in this simulation (even it is likely in reality).
When increasing tree diversity, another type of tree grow in the forest, which bark beetles cannot use as food and shelter.
Days 1-2: Ask questions to obtain information
Students learn about the bark beetle outbreak phenomenon, observe the specimens of tree bark and bark beetle, ask questions, and read to obtain information about the bark beetle life cycle and the interactions between bark beetles and host trees.
Days 3-4: Develop and use a model to investigate changes in populations
Students conduct a kinesthetic activity to model and understand the interaction between bark beetles and trees and reveal the dynamic nature of the changes over time.
Day 5:Analyze data to identify possible disruptions to the forest ecosystem
Students analyze climate data collected by scientists to identify a rise in global temperatures over the past several decades.
Days 6~7: Use a computer model to investigate the impacts of climate change on bark beetle populations
Students carry out an investigation on the effect of rising temperatures on the severity of bark beetle outbreaks by collecting data at five different mean temperatures.
Day 8: Construct a written argument supported by evidence
Students constructed a written argument about the cause of recent bark beetle outbreaks using the evidence and information from the unit.
*The teaching sequence above only focuses on the effect of rising temperature on bark beetle outbreak. A similar design can be applied to have students investigate the effect of drought or tree diversity of bark beetle outbreak. Find further teaching information in the following publication:
Xiang, L. & Mitchell, A. (2019). Investigating Bark Beetle Outbreaks in Forest Ecosystems Using Computer Models. Science Scope, 46(6), 65-67. https://common.nsta.org/resource/?id=10.2505/4/ss19_042_06_65
This unit was designed by
April Mitchell, Science Coach, Salt Lake City School District
Dr. Lin Xiang, Assistant Professor of Science Education, University of Kentucky
The NetLogo model was developed by Dr. Lin Xiang at Weber State University. If you mention this model in a publication, we ask that you include the citations below.
Xiang, L. (2017). Bark Beetle Epidemic. Zoology Department, Weber State University, Ogden, UT. https://sites.google.com/view/3d-science-abm/ecology/bark-beetle-epidemic
