HS - LS2.A - Interdependent Relationships in Ecosystems - ASSIGNED (AuMy 1/30/2014)

Module: Interdependent Relationships in Ecosystems

DCI: LS2.A Ecosystems have carrying capacities, which are limits to the number of organisms and populations they can support. These limits result from such factors as the availability of living and nonliving resources and from such challenges such as predation, competition, and disease. Organisms would have the capacity to produce populations of great size were it not for the fact that environments and resources are finite. This fundamental tension affects the abundance (number of individuals) of species in any given ecosystem.

PE: HS-LS2-1 Use mathematical and/or computational representations to support explanations of factors that affect carrying capacity of ecosystems at different scales.

PE: HS-LS2-2 Use mathematical representations to support and revise explanations based on evidence about factors affecting biodiversity and populations in ecosystems of different scales.

[Clarification Statement: Emphasis is on quantitative analysis and comparison of the relationships among interdependent factors including boundaries, resources, climate, and competition. Examples of mathematical comparisons could include graphs, charts, histograms, and population changes gathered from simulations or historical data sets.] [Assessment Boundary: Assessment does not include deriving mathematical equations to make comparisons.]

[Clarification Statement: Examples of mathematical representations include finding the average, determining trends, and using graphical comparisons of multiple sets of data.] [Assessment Boundary: Assessment is limited to provided data.]

The ideas in this standard are: 

- ecosystems have carrying capacities (limits to the number of organisms and populations that the ecosystem can support) 

- the limits are the result of certain environmental factors (availability of resources and other challenges to the population.) 

- If it weren't for these limits on population sizes, the population size would grow without restriction. 

- the tension that results from the limits on resources affects the number of individuals of species in any ecosystem 

The first PE says that we should use mathematical or computational representations to explain how different factors affect an ecosystem's carrying capacity. This is made clearer by the clarification statement, which tells us that we can use graphs, charts and histograms in order to make mathematical comparisons.  We do not have to provide any kinds of equations for students to use in order to make explanations. 

Additionally, the second PE asks us to use mathematical representations.  Again, that is made clear by the clarification statement which says to find the average, trends, or make comparisons of data sets.  We can not expect students to know how any one single population has changed as a result of carrying capacity, but we can provide data and have them analyze it. 

Possible Question Starters: 

I stole this picture from the internet - we will have to replace.  I'm picturing something with only the line showing the changes to the population. But, we can ask something like this...

"The graph shows how the population of _______ changed between the years of 1800 and 1925.  

Based on the information in the graph, we can conclude that the carrying capacity of the ecosystem for this organism was around _____?"

Correct answer - 1.5 million 

I stole this picture too.  We can come up with something similar. 

Basically, it's just a concept map.  We can label a much more simplified version and ask "which of the following would be the best replacement for the letter X in the diagram?"