Biodiversity and ecosystem services

9.Yellowstone Lake has supported recreational cutthroat trout fishing for over a century. Which category of ecosystem service is this?

10.Why is biodiversity important to humans?

11.Explain why it is important to conserve biodiversity, even if some species seem abundant. Refer to ecosystem services and the idea of a ripple effect.

12.A group of poachers argue: "There are plenty of wild animals and plants left, so it doesn't matter if a few become extinct." Write 3-4 sentences explaining why we should still care about protecting biodiversity.

13.Which of these is NOT one of the major human activities that puts biodiversity at risk?

14.Which of the following are human activities that harm ecosystems? (select all that apply)

15.Invasive species often have no natural predators in their new habitat.

16.Arrange the following events in the order they occur when an invasive species is introduced into an ecosystem.

17.What is the primary reason invasive species like lake trout threaten native species?

18.A newly introduced fish species in a lake has no natural predators and grows larger than the native fish. What is the most likely long-term effect on the native fish population?

19.What is the main reason lake trout are a threat to cutthroat trout in Yellowstone Lake?

20.Which of the following are potential consequences of introducing nonnative lake trout into Yellowstone Lake? (select all that apply)

21.What percentage of its historic highs had the Yellowstone cutthroat trout population fallen to?

22.About how many cutthroat trout can a single mature lake trout eat per year?

23.If a lake had 500 mature lake trout, each eating about 41 cutthroat trout per year, roughly how many cutthroat trout would they eat between them in a year?

24.If a lake had 500 mature lake trout, each eating about 41 cutthroat trout per year, roughly how many cutthroat trout would they eat between them in a year?

25.Gillnetting has removed more than 3 million lake trout from Yellowstone Lake since 1994.

26.Yellowstone managers compared eliminating every fish in the lake and restocking cutthroat trout (estimated cost $32-181 million) with gillnetting some, not all, of the lake trout. Which is more likely to maintain ecosystem stability?

27.Which of the following were solutions Yellowstone National Park management actually proposed for the lake trout problem? (select all that apply)

28.Park managers are comparing intensive gillnetting with hiring anglers to catch lake trout. Which of the following is a valid reason gillnetting is likely to be more effective at reducing the lake trout population?

29.The diagram shows Yellowstone Lake's food web before and after 1985. Based on the diagram, what happened to the Gammarus population after 1985?

30.Using the food web diagram, explain why the Gammarus population increased after 1985, even though lake trout do not eat Gammarus directly.

31.A wildfire burns most of the grass and some of the trees in a grassland ecosystem. Describe a likely short-term effect and a likely long-term effect on the ecosystem.

32.What is the independent variable in this experiment?

33.What is the control group in this experiment?

34.Which variables need to be kept constant between the two trays for this to be a fair test?

35.Guppies tolerate a wide range of environments and eat many food sources, including mosquito larvae, so they have been introduced into ecosystems worldwide to help control mosquito populations. In Malaysia, mosquito control methods include: draining standing water where mosquitoes breed, releasing guppies to eat mosquito larvae, using an insecticide (ABATL) that kills mosquito larvae, and fogging with an airborne insecticide that kills adult mosquitoes. Which of these methods best controls mosquitoes while maintaining biodiversity in the ecosystem?

36.Giraffe populations across Africa have shrunk due to habitat loss, disease, climate change, and hunting; the map compares their historic range with their much smaller present range. One conservation strategy is to replant Acacia trees, a key giraffe food source, in areas where giraffes historically lived. Describe how this reforestation helps protect the stability of giraffe populations in African savanna ecosystems.