Question

Pine rockland is an endangered ecosystem found only in South Florida. Invasive plant species threaten pine rockland by out competing the native plants and providing no nutritional value to native wildlife. The largest tract of pine rockland in Everglades National Park is at Long Pine Key. Scientists with the National Park Service are interested in knowing how effective different frequencies of prescribed burns are at removing invasive plant species. They measured the density (individuals/m²) of invasive plant species in an area that was not burned (no burn), an area that was burned once in the last 5 years (infrequent burn), and an area that was burned 5 times in the last 5 years (frequent burns). For each area, sampling was conducted by measuring the density at 20 random points.

Based on observations of these three areas and the need to decrease invasive species in these ecosystems, we could put forth the following question: How does the frequency of prescribed burns affect invasive plant species in pine rockland ecosystems?

1. For the study above, identify the following: (4 points)
   1. Population: All invasive Plant species in Pine Rockland Ecosystem.
   2. Sample: 20 random points in each area
   3. Parameter:
   4. Statistics
2. For the study above, identify the following: (3 points)
   1. Dependent Variable
   2. Independent Variable
   3. Is the independent variable categorical or numerical?

Answer 1

b)

Independent variable: It is the variable that can be changed or controlled in an experiment to test the effect on the dependent variable. The independent variable of this experiment is different frequencies of prescribed burns.

c) Independent variable the different frequencies of prescribed burns are divided into three groups: no burn, infrequent burn, and frequent burn. Hence, the Independent variable is a categorical variable.