The diagram shows the watershed around an underground mine. Stream 3 runs from the top of the mountain ridge to the lake. The entire watershed is underlain by bedrock that contains some metal. A town on the lakeshore is concerned because of an increase in metal contaminants in the lake.

(a) Based on the diagram, describe how human activities could have increased the amount of sediment in stream 2.

(b) Based on the diagram, explain why the risk of flooding is greater near stream 2 than near stream 1.

(c) Based on the diagram, make a claim using evidence that a provisioning ecosystem service has been devalued as a result of human activities.

(d) Based on the diagram, describe how the location of stream 4 could affect the phosphorus cycle in this area.

(e) Explain why soil-forming over a volcanic rock might differ from soil-forming over a different type of bedrock, such as sandstone or limestone.

(f) Some of the miners assert that the area in which the ore is being mined must have been located at a divergent plate boundary. Make a claim using evidence that supports or opposes the miners’ assertion.

(g) The mining company claims that they cannot extract enough ore from the mine and wants permission to convert the mine into a strip mine. Describe why converting the mine into a strip mine may not be the best choice for the ecosystem of the area.

Scientists are interested in investigating the possibility that plants can be used to remove heavy metals from contaminated soil. They divide a sample of soil with heavy metal contamination into five different pots and plant five different species of grass they believe will take up metals into their roots and leaves. They also plant the same grasses in five pots with uncontaminated soil. After allowing the grasses to grow for a month, they cut the grass and measure the concentration of metals in milligrams per kilogram.

(h) Identify the independent variable for the investigation.

(i) Identify one variable that was not mentioned in the description above that could affect the results of the investigation.

(j) After determining the species of grass that removes the most metal, it is planted in the area that was logged. In addition to removing metals from the soil, describe one advantage to stream 2 of planting grass in this area.
 

Rain, Mine entrance Tailings Clear-cut forest Stream 2 Stream 3 Mine entrance Mine Highway tunnels Stream 1 Stream 4 Tailings Ore deposits Volcanic rock Lake Sediment