Which species in the simulation is capable of nitrogen fixation?
Members of which species in the simulation are commonly known as “water fleas”?
Briefly describe what happens in the simulation when phytoplankton die.
Based on your sampling, what do Bosmina in the lake eat?
Based on your sampling, what do Daphnia in the lake eat?
Based on your sampling, what do Trout in the lake eat?
Daphnia and Bosmina.
After reading the above statement, did you miss any species in your gut content sampling? If so, which ones?
The specie I missed was cyanobacteria.
Exercise 2: P in the Water.
When the simulation stops, record the population size of green algae (from the graph), and the dissolved oxygen (DO) level.
Phosphorus input | Green Algae Population Size | Dissolved Oxygen (Mg/L) |
1x | 184 | 6.8 |
2x | 335 | 3.8 |
3x | 487 | 1.7 |
Draw a line graph of your green algae population size data to show how green algae relate to phosphorus input levels.
Does the relationship between green algae population size and phosphorus level indicate that phosphorus was a limiting nutrient for green algae in the lake? Explain.
Yes it does indicate that phosphorus is a limiting nutrient. With phosphorus at a normal level the green algae population does not increase in size too much. As we add more phosphorus the population size increases dramatically.
Draw a line graph showing how oxygen relates to phosphorus population size.
What is the relationship between dissolved oxygen and phosphorus in the lake?
The higher the level of phosphorus is the lower the dissolved oxygen is.
Based on your two graphs, what is the relationship between green algae population size and dissolved oxygen the lake? Provide a biological explanation for your answer.
The graphs show the green algae population increasing as the dissolved oxygen level decreases. This is a result of the increased green algae population consuming the dissolved oxygen. The level of dissolved oxygen drops because the oxygen being consumed is greater than what is being produced.
DO or DIE
Thinking about the trophic relationships of the species, do you think the green algae populations will be smaller, larger, or about the same as in your previous experiments.
I think the green algae population will be smaller than previously because they are competing with cyanobacteria for food.
Do you think the dissolved oxygen concentration will be lower, higher, or about the same as in previous experiments?
The dissolved oxygen will be higher than previous experiments. I think it will be higher because the more species in the lake fighting for same nutrients, and some of those species will die off. This can help with the producing of dissolved oxygen.
Which species do you expect to be impacted the most by the increased phosphorus, and why?