Invasive Plants

What makes a plant a WEED? Brainstorm what a weed is… A plant (unwanted) that takes over a specific population. Why are they “bad”? Cheatgrass can enhance fires.

Types of Idaho Weeds Cheatgrass Hoary Cress Medusahead Puncturevine

Invasive Plants Simulator How it works: https://idoteach.boisestate.edu/modal/invaders/ Options: Plant Landscape Number of Starting Spots Grid Size Choose Starting Spots? Other buttons: Arrows, Run, & Reset Simulator Rule for spreading: “If you have a weed in one spot, it can spread to any _____ spots it touches.”

Questions before we start What is different about these three Year-0 grids? Would we expect different Year-1 results in each grid? Why? Would we expect the rate of spread to be different? Why?

Which weed has the fastest rate of spread? Question of the day... Which weed has the fastest rate of spread? Cheatgrass Hoary Cress Medusahead Puncturevine Be prepared to defend your answer.

Things to think about as you explore... How much data will you collect? Is the data you are collecting giving you information about the rate of spread? How will you organize your data? How will you represent your data in a graph or picture? What evidence will you use to support your conclusion?

Conclusions Take notes on the questions you have as groups share and defend their conclusions.

Follow-Up Discussion Questions Which weed spreads the fastest? How do we know? Does the landscape matter? Does the size of the landscape grid matter? What is the most invasive weed’s rate of spread? How do we know or how could we find out? What could we do to improve our estimate? What are the units for this rate of spread? Using this estimated rate of spread, how many new plants would we expect if we started with 2 plants, 5 plants, 100 plants, or n plants? How could we communicate the relationship between the number of expected new plants and the number of starting plants using an equation? A table? A graph?