Exam 20: Production

Suppose that heterotrophs ingested 1,560 kilograms of plant biomass over a month's period. Respiration of these heterotrophs was the equivalent of 900 kilograms, and they egested 420 kilograms. What is the net secondary production?

What did John Martin mean when he said "Give me half a tankerload of iron, and I'll give you an Ice Age"?

Which statement about net secondary production is true?

Refer to the table and the figure. Table 2 Figure 1 -You are studying the movement of energy through an ecosystem. You collect data on energy use at the same site across four years, measured in g/m²/year. Assume that the site is sampled at the same location on the same date each year. What is the average NPP at your study area across all four study years? Compared to levels of NPP observed in different areas on Earth, how does your data differ? Where was your study area most likely located?

Harvest techniques would likely be the least problematic for estimations of _______ in _______.

Refer to the table and the figure. Table 2 Figure 1 You are studying the movement of energy through an ecosystem. You collect data on energy use at the same site across four years, measured in g/m²/year. -Assume that the site is sampled at the same location on the same date each year.Answer the following questions: a) In which year was GPP the highest? b) Were NPP and NEE also highest when GPP was highest? c) In which year was GPP the lowest? d) Were NPP and NEE also lowest when GPP was lowest? e) In which year was the difference between GPP and NPP the greatest? f) In which year was NEE the smallest?

Imagine you are investigating the possibility that algae can grow on clouds in the upper atmosphere. First you must determine how to sample NPP and predict how NPP in clouds would affect terrestrial and marine systems. What would be the most efficient way to determine the amount of GPP produced by these hypothetical cloud algae? Would you predict that these hypothetical cloud algae would have a positive or a negative impact on the productivity of surface-level biomes (terrestrial and marine)? Describe the predicted relationship, and explain why you think the productivity of the aerial and surface systems would exhibit this pattern.

Which of the following is not an advantage of remote sensing technologies over harvesting estimates of NPP?

In most ecosystems, as NPP changes during ecosystem development, it is highest during _______ succession.

Which of the following is responsible for the most NPP produced within river and stream ecosystems?

In hydrothermal vent communities, colonization begins with chemoautotrophic bacteria, which often are followed by

How does one estimate the NPP if one knows the NEE (net ecosystem exchange)?

Which method(s) of estimating NPP is typically used in aquatic ecosystems?

Imagine you are investigating the possibility that algae can grow on clouds in the upper atmosphere. Is there an ecosystem that would be unaffected by the productivity of the hypothetical cloud algae?

Suppose that the NEE of a boreal forest ecosystem is 120 units per month. The respiration by autotrophs is 60 units per month, and the respiration by heterotrophs is 30 units per month. What is the NPP of the forest?

Refer to the figure. Heterotroph diets can be determined by measuring and comparing the ratios of stable isotopes in tissues. The figure shows C and N isotopic ratios for cave bears and Pleistocene herbivores. Which of the following is true?

If the GPP of a forest ecosystem is 350 units per year and the NPP is 100 units per year, what is the respiration rate of the primary producers?

Hilderbrand and colleagues wanted to determine the feeding ecology of the extinct European cave bear to determine whether individuals were herbivorous. To investigate this question, they

If the NPP of an ecosystem is 240 units per year, and the respiration by autotrophs is 110 units, what is the amount of energy available for increases in plant biomass?

Which statement about roots and root NPP is false?