1. Agenda 10/23 Ecology Word Association
Species composition and chi-square overview
Species composition ‘lab’
Homework:
1. WB #119, 120, and 121
2. ‘Communities’ Video and Notes

2. Ecology Our next unit is ecology…
On a sheet of paper, make a list or a collage of all the topics you think may come up during this unit
No right or wrong answers, just a way to see what you already know!

3. Species Composition
A crucial thing to study in ecology is species composition
This is the study of how many species are in a specific ecosystem
For example, scientist may want to determine how many squirrels are living in east charlotte vs. how many are living in uptown
What are some difficulties with collecting this data?
How could we effectively gather data?

4. Quadrant Sampling

5. Quadrant Sampling
Scientist select a small area of an ecosystem (a quadrant)
They record the number of species in the quadrant
They can then determine the approximate number of species in the ecosystem, or the species density

6. Quadrant Sampling Example Problem
1. Calculate the density of flowers assuming the quadrant is 2 m2
2. If the entire ecosystem is 25 m2, how many total flowers would you expect to be present?

7. What can we do with that data?
Once we know the amount of species present, we can then analyze that data further using a chi-squared test
This may be a helpful statistical tool for your IA research

8. Chi-Squared Example Problem
A poker-dealing machine is supposed to deal cards at random, as if from an infinite deck.
In a test, you counted 1600 cards, and observed the following:
Spades 404
Hearts 420
Diamonds 400
Clubs 376
Could it be that the suits are equally likely? Or are these discrepancies too much to be random?