Apes Tundra FRQ

Tundra (a) Based on the graph identify the percent cover of mosses in the unburned plot

About 5%

Tundra (b) Based on the graph identify the dominant groundcover in the plot burned 32 years before data collection

Shrubs

Tundra (c) Based on the graph describe the percent coverage of sedges and grasses in the unburned plot compared to the plot burned most recently

Higher in the unburned plot at about 16% than in the 2 year plot at about 12%

Tundra (d) A researcher hypothesizes shrubs will dominate the tundra in later succession stages. Make a claim based on the graph to support or refute this

Refutes it. Shrub cover peaks around 32 years at about 42% then drops to about 33% at 46 years and about 28% in the unburned plot. The most mature plot is dominated by lichens at about 48% so shrubs do not keep increasing

Tundra (e) Describe how lichen could be used as an indicator species for high levels of acid precipitation

Lichens absorb sulfur dioxide straight from the air. If they are dying or missing then SO2 and acid precipitation are likely high

Tundra (f) Identify the dependent variable for the thaw depth and organic thickness investigation

Average thaw depth and average surface organic thickness

Tundra (g) Measuring surface organic material in different seasons: how could this alter the results

The organic layer would likely be thinner in summer from more decomposition and thicker in fall from new litter so results would change with the season measured

Tundra (h) Describe the relationship between average surface organic thickness and time since the last fire

Inverse. Thickness is highest at 12 years (37 cm) and drops as time passes (35.5 cm at 32 years and 31.5 cm at 46 years)

Tundra (i) Explain why a scientist would test phosphate levels in burned and unburned plots

Scientists test for phosphate levels in the soil to see how the burning affected the nutrient levels in the soil. If there was a decrease in phosphate levels, then the fire had reduced the amount of nutrients in the soil. If the amount of phosphate remained the same, then the fire didn't pull any nutrients from the soil.

Tundra (j) Make a claim about soil nutrient levels in clay loam compared to loamy sand

Clay loam is more nutrient rich than loamy sand soils. This is because the clay holds more water and nutrients than sand.