AP Environmental Science Unit 1 FRQ

(a)(iii) A climatograph for a tropical grassland or savanna would look different from the climatograph shown for a temperate grassland. Describe one difference in the patterns or trends in the temperature data in a tropical grassland compared to those of a temperate grassland.

The response identifies higher average temperatures or higher maximum temperatures as the difference between the two grasslands.

(a)(i) Identify the month with the least amount of rainfall in this temperate grassland.

The response indicates January.

(a)(ii) Identify the maximum mean monthly temperature in this temperate grassland.

The response indicates a value between 27 and 28 degrees Celsius.

(b)(i) Describe one way that grazing animals, such as bison or cattle, help to maintain grassland ecosystems.

-Animals compact the soil with their hooves. -Animal waste provides nutrients for soil/plants. -Animals open new areas for seed to grow by moving over areasand disrupting grasses -Animals spread seeds to new areas.

(c) Humans often convert grasslands into farm fields to grow crops. Describe why the conversion of temperate grasslands, such as in the central United States, into agricultural areas is an environmental problem.

-Areas of diverse grasses and shrubs replaced by monocultures/less species diversity -Removal of groundcover can lead to desertification/erosion -Need for irrigation depletes groundwater/aquifers -Irrigating soils can lead to soil salinization

(b)(ii) Explain how seasonal fires benefit grassland ecosystems.

-Decaying/dead plant matter burns and turns to ash, which releases nutrients into a useable form for plants -Cleared areas receive more sunlight which stimulates dormant plants to sprout and grow -Trees and shrubs are killed off opening the area for grasses (secondary succession) -Heat from fires promote germination from seeds in seed banks