1. Case Study: Cascading food-web Effects of invasive species

2. Objectives You should be able to…
Identify and describe ecosystem services
Create a model of a food-web that includes the biotic interactions
Predict outcomes of disturbances related to management decisions
Explain the possible consequences of invasive species

3. What is an ecosystem service?
Benefits people obtain from ecosystems
Rainforest
So lets define an ecosystem service.
Ecosystem services are a result of complex ecosystem interactions. Many of the services we have discussed are very valuable to us. These services are valuable but free!
Now, using our rainforest ecosystem, can I hear a few of your ideas about what ecosystem services we obtain from rainforests.
In fact, the tropical rainforests are the single greatest terrestrial source of air that we breathe.
"37% of all medicines prescribed in the US have active ingredients derived from rainforest plants." "70% of the plant species identified by the US National Cancer Institute as holding anti-cancer properties come from rainforests.“
"90% of the rainforest plants used by Amazonian Indians as medicines have not been examined by modern science." "of the few rainforest plant species that have been studied by modern medicine, treatments have been found for childhood leukemia, breast cancer, high blood pressure, asthma, and scores of other illnesses."
The tropical rainforests are being destroyed at an alarming rate. "If present rates of destruction continue, half our remaining rainforests will be gone by the year 2025, and by 2060 there will be no rainforests remaining." Every second . . we lose an area the size of two football fields!

4. Great Lakes Coastal Wetlands
What about Great Lakes Coastal Wetlands…is this a place that you would like to hang out for fun and sun? Probably not, but they provide important ecosystem services such as water treatment. MAKE A QUICK POINT ABOUT THE COMPLEX INTERACTIONS THAT MAKE UP THE ECOSYSTEM SERVICE.

5. Coastal waste water treatment facility
Think of waste treatment facilities and how much it would cost to build, run and maintain. The East Lansing waste treatment facilities, can handle Million Gallons per Day capacity (presently treating 12.6 millions gallons per day) and is staffed 24 hours per day, 7 days per week. An approximate cost to treat waste water is $729 per million gallons treated. That means that it costs $9,185 per day just to treat the water which is $3,352,671 per year. This does not include building costs, or the cost of employing staff 24 hrs a day 7 days a week. A comparable natural waste facility is a wetland or waste treatment pond, which provides the same function for free. Today we want to tie together these complex ecological interactions and how they work together to provide services.

6. Wetland management for waste water treatment (hybrids)
Now, we are making “hybrids”, we are managing wetlands for water treatment.

7. Boreal forest ecosystem
Ok, now what about this ecosystem (boreal forest)? What services do you think we obtain from the boreal forest?
Is the boreal forest a source or a sink for carbon? Why do you think it is a sink? Look at where boreal forests are on the map…what is the weather like there?
MAKE A QUICK POINT ABOUT THE COMPLEX INTERACTIONS THAT MAKE UP THE ECOSYSTEM SERVICE.
If the carbon reservoir in peatlands were to decompose and all was emitted to the atmosphere, there would be a doubling of atmospheric CO2 concentrations

8. The balance of nature is very delicate and easy to upset
strongly agree
Agree
Neutral
Disagree
strongly disagree

9. Humans have the right to modify the natural environment to suit their needs
strongly agree
Agree
Neutral
Disagree
strongly disagree

10. The amount of grass will increase. The amount of grass will stay the
A national park is home to large populations of mountain lions, deer, rabbits, and grass. Recently, park rangers decided to introduce wolves to the park. If the number of deer and rabbits eaten by the mountain lions stays the same, what will happen to the grass after wolves are introduced? Use only the relationships between the plants and animals described above.
The amount of grass will increase.
The amount of grass will stay the
same.
C. The amount of grass will decrease.

12. Flathead Lake Ecosystem
Orient on map.
For homework, you build a model of the natural Flathead Lake ecosystem. Now, take out your models. Let’s take a few minutes for you to compare your model with your neighbors model.

13. Phytoplankton
Cladocerans
Copepods
Kokanee Salmon
Lake Trout
Bald Eagles
Grizzlies

14. What species was introduced in the 1970s?
More bald eagles
Oppossum shrimps
Lake trout
Coho salmon

15. Why were the shrimps introduced?
To increase the number of lake trout
To increase the number of tourists coming for wildlife viewing or fishing
To increase the number of kokanee salmon
Both B and C

16. Activity: Redraw the food web, adding the shrimp to show what the management team wanted to happen – make sure you consider the strength of interactions (i.e. arrow size)
Use your model to answer the next question.
What they wanted to happen!

17. What the management team wanted
Lake Trout
Bald Eagles
Grizzlies
Kokanee Salmon
Opossum shrimp
Cladocerans
Copepods
Phytoplankton

18. Flathead Lake Ecosystem
Spend a few minutes here to discuss the connection between salmon, flathead lake, and the connecting rivers. McDonald Creek is the main wildlife viewing area in Glacier National Park. It is connected to the Flathead Lake via the Flathead River.

19. Did it work? A: Yes, B: No
(=shrimps)

20. Redraw the food web, this time showing what actually happened
Activity
Redraw the food web, this time showing what actually happened
Hint: the food web stays the same, but the arrow sizes (= the strength of species interactions) change
Beginning 3rd model here..
Now students are displaying what really happened after the shrimp was introduced.

21. What actually happened
Lake Trout
Bald Eagles
Grizzlies
Kokanee Salmon
Opossum shrimp
Shrimps ate all the zooplankton, and managed to avoid being eaten by the salmon by migrating down during the day Shrimps also shift the behavior of the zooplankton, who end up migrating too
Cladocerans
Copepods
Phytoplankton

22. The salmon don’t like to eat the shrimps
Why did the management strategy NOT work in the Flathead Lake ecosystem?
The salmon don’t like to eat the shrimps
The bald eagles ate all the shrimps
The shrimps could escape the salmon by migrating to deep waters during the say
The salmon died because the water levels became too low
Question to discuss, write, or discuss + write.
Answers:
Flathead Lake is deeper than other experimental lakes
Salmon only increased in the short term in the other lakes, but eventually collapsed too.
Predation by shrimp on zooplankton populations was higher than anticipated
Shrimps migrate up and down to avoid being eaten by salmon

23. The balance of nature is very delicate and easy to upset
strongly agree
Agree
Neutral
Disagree
strongly disagree
Introduced species only need to be removed if they threaten native species.
Ecosystems will eventually adapt to introduced species.
The cost of preventing species introductions – or removing invasive species – is too high to consider.
The earth has plenty of natural resources if we just learn how to develop them
The balance of nature is very delicate and easily upset
Humans will eventually learn enough about how nature works to be able to control it
Humans have the right to modify the natural environment to suit their needs

24. Humans have the right to modify the natural environment to suit their needs
strongly agree
Agree
Neutral
Disagree
strongly disagree
Introduced species only need to be removed if they threaten native species.
Ecosystems will eventually adapt to introduced species.
The cost of preventing species introductions – or removing invasive species – is too high to consider.
The earth has plenty of natural resources if we just learn how to develop them
The balance of nature is very delicate and easily upset
Humans will eventually learn enough about how nature works to be able to control it
Humans have the right to modify the natural environment to suit their needs

25. The amount of grass will increase. The amount of grass will stay the
A national park is home to large populations of mountain lions, deer, rabbits, and grass. Recently, park rangers decided to introduce wolves to the park. If the number of deer and rabbits eaten by the mountain lions stays the same, what will happen to the grass after wolves are introduced? Use only the relationships between the plants and animals described above.
The amount of grass will increase.
The amount of grass will stay the
same.
C. The amount of grass will decrease.

26. The diagram below shows the feeding relationships between populations of organisms in an area. The arrows point from the organisms being eaten to the organisms that eat them. Using only the relationships between the organisms shown in the diagram, what will happen to the number of mice if most of the frogs are killed and why?
The number of mice will decrease because the number of individuals in all of the populations of organisms in this diagram will decrease.
The number of mice will decrease because there will be more grasshoppers to eat the grass, so there will be less grass available for the mice to eat.
The number of mice will stay the same because there will be no effect on the number of individuals in the populations of organisms below the frogs in the diagram.
The number of mice will stay the same because
frogs and mice are not connected by an arrow
in the diagram.