BEAVER, ELK, and TREES in YELLOWSTONE PARK An Interactive PowerPoint Experiment

Teachers – Before viewing the slide show, right click on the document below. Go to Document Object and select Open. Print out worksheet and have students complete while viewing the PowerPoint.

INSTRUCTIONS You will need to take data in order to analyze what is going on and to answer questions at the end of the lesson. Pay attention to what is happening to the population of beaver, aspen, willow, and conifers. As the years go by, mark with a plus (+) if the population increases, and a minus (-), if it decreases.

YEAR 1900 ELK POPULATION: LOW

YEAR 1910 ELK POPULATION: LOW

YEAR 1920 ELK POPULATION: LOW

YEAR 1930 ELK POPULATION: LOW

YEAR 1940 ELK POPULATION: LOW

YEAR 1950 ELK POPULATION: LOW

YEAR 1960 ELK POPULATION: LOW

YEAR 1970 ELK POPULATION: LOW

YEAR 1900 ELK POPULATION: HIGH

YEAR 1910 ELK POPULATION: HIGH

YEAR 1920 ELK POPULATION: HIGH

YEAR 1930 ELK POPULATION: HIGH

YEAR 1940 ELK POPULATION: HIGH

YEAR 1950 ELK POPULATION: HIGH

YEAR 1960 ELK POPULATION: HIGH

YEAR 1970 ELK POPULATION: HIGH