Download V. Interpreting Ecological Models Ecological systems are composed

V. Interpreting Ecological Models
Ecological systems are composed of an enormous number of biotic and abiotic factors that interact with each other in ways
that are often unpredictable, or so complex as to be impossible to incorporate into a computable model. So, ecosystem
models typically simplify the systems they are studying to a limited number of components that are well understood, and
deemed relevant to the problem that the model is intended to solve.
Describe what is happening to the population.
Cite Evidence.
2. What is the carrying capacity for the given
species? Cite Evidence
Number of Organisms
1.
3. During which month was there exponential
growth? Cite evidence.
2. In 2000, how many organisms had a 3 cm length?
3. In 2000, what is the average length?
4. In 1800 what was the average length?
Number of Organisms
1. In 1800, how many organisms had a 3 cm length?
1
2
3
4
5
6
7
Length
8
9
10
11
In order to estimate the population of organisms in your ecosystem, ecologists marked 10 organisms then released them
back into the population. Over a 6 year period, organisms were trapped and their numbers recorded.
Year
1
2
3
4
5
6
Organisms Trapped
10
15
12
8
5
10
Number with Mark
1
1
1
0
2
1
(Total Number Captured) x (Number Marked)
(Total Number Recaptured with Mark)
1. Use the formula to calculate the estimated number of organisms in the area studied.
2. Supposing more of the organisms found in the trap found in the trap had the mark, would the estimated number of
organisms in the area be greater or lesser? Explain.
3. What are some limitations of this model? Explain.
Another ecologist uses a different method to estimate the number of organisms in a given area. She plots a 10x10 area and
randomly chooses 5 spots, where she counts the number of organisms and records them on the grid.
2
5
3
3
2
1.
Calculate the number of organisms based on the grid data.
2.
What are some limitations of this model? Explain.