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.

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. LOW ELK POPULATION HIGH ELK POPULATION

Beaver Aspen Willow Conifer 1900

1910

1920

1930

1940

1950

1960

1970

Beaver Aspen Willow Conifer 1900

1910

1920

1930

1940

1950

1960

1970

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