Q6. Imagine that the population of aquatic insects doubled in acertain pondweed area. How would the net primary productivitychange from an area where the aquatic insect population were at thenormal level? In your answer, make sure you explain what netprimary productivity is and why it would change with moreinsects.

In addition to grass carp, another large herbivore in the GreatLakes are Canadian geese. Early accounts by naturalists in the1800s suggest that grass carp and Canadian geese were often seenfeeding side by side among pondweeds. However, in the last threedecades, this is rarely seen. Imagine that grass carp and Canadiangeese previously ate both floating-leaf pondweed and curly-leafpondweed and there was significant competition between them.However, there were some individuals of grass carp that specializedon pondweed patches dominated by curly-leaf pondweed and there weresome individuals of Canadian geese that specialized on patchesdominated by floating-leaf pondweed.

Q7a. In the space below, draw 2 figures. The first one showingthe niches for grass carp and Canadian Geese in the early 1800swith regard to the type of pondweed they fed on and then a secondfigure showing the niches now. Make sure you properly label theaxes, tick marks, and including an appropriate figurelegend.  

Q7b. What is an explanation for why we see the pattern shown inyour figures above occur often in ecology?  

Q8. Imagine that a forest along a small inlet of the Great Lakeswas clear cut and replaced by a large farm growing corn. The farmeruses a large amount of fertilizer just before a large rain stormcomes through the area. Two weeks later there is a dead zone in thesmall inlet of the lake. List 3 ways in which humans have impactedthe nitrogen cycle in this example.

1.

2.

3.

Q8b. Explain in 2 sentences why a dead zone occurs.