Ecology - Ecosystem Ecology Questions
1. To measure primary production of algae in a stream, you placetwo sealed chambers in the stream, each enclosing the sediments aswell as the water above them. One chamber is covered with blacktape (blocking all light) while the other is transparent tolight.
You measure dissolved oxygen (DO) before and after a 24-hourincubation. DO in the light chamber increases by 30mg/m2 while DO in the dark chamber decreased by 10mg/m2.
What is the estimated Re for the stream? mg O2m-2 day-1
2. What is the stream's esitmated NEP? mg O2m-2 day-1
3. Based on these data, what was the stream's GPP? mgO2 m-2 day-1
4. The position of Earth's continents has shifted dramaticallyover its history. Imagine that all of Earth's land mass was bunchedtogether with approximately equal areas above and below theEquator. Assume that seasonal patterns of growth and respirationare otherwise similar, with the Northern Hemisphere's summeroccurring June-August and the Southern Hemisphere's summeroccurring December-February.
How will this new configuration affect seasonal swings in averageglobal CO2?
a. Seasonal swings would be larger, butCO2 would still peak in late April.
b. Seasonal swings would be similar, butCO2 would now peak in late August.
c. Seasonal swings would be larger, butCO2 would now peak in late August.
d. Seasonal swings would be much smaller, perhapseven undetectable.
5. In the four-link food chain shown to the right, plants areinfested by caterpillars, caterpillars are parasitized by braconidwasps, and braconid wasps are parasitized by tiny iridescent wasps.What can you say about whether each of the Eltonian pyramids(energy, numbers, and biomass) describing this system will beinverted or not? Give reasons for your predictions using theconcepts in this section.