Exam 20: Production

Suppose that the NEE of a temperate grassland ecosystem is 200 units per month. The respiration by autotrophs is 195 units per month, and the respiration by heterotrophs is 80 units per month. What is the NPP?

For which purpose would a minirhizotron be a useful tool?

Suppose that the net primary productivity of a particular ecosystem is 80 units per year. The respiration rate of primary producers is 30 units per year, and the respiration rate of herbivores is 10 units per year. The gross primary productivity is _______ units per year.

Refer to the table. Table 2 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. Use the data in Table 2 to graph GPP, NPP, and NEE as a line graph (this will be referred to as Figure 1). The x-axis should be years 1-4 and the y-axis should be productivity in g/m²/year from 0-7,000.

Refer to the figure. The normalized difference vegetation index (NDVI) explores the difference in absorption by plants and soil as a proxy to infer plant biomass. If NDVI uses a 600 nm and 1,000 nm wavelength in its estimation, what other wavelengths of light would be useful in distinguishing plants from soil?

Suppose that the net secondary production in a community is 530 kilograms. The respiration of heterotrophs is 1,400 kilograms, and the egestion is 350 kilograms. Plant respiration is 2,700 kilograms. How much plant material did the heterotrophs ingest?

Heterotrophs are categorized by what they eat. A detritivore eats

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. Assume your study area is indeed located in a tropical forest. How would you expect climate change that causes an increase in average annual temperatures to affect GPP, NPP, and NEE? How would you expect the experimental addition of fertilizer to affect the study area?

In freshwater ecosystems, the presence of descending Hadley cells tends to _______ NPP, and the presence of upwelling cells tends to _______ NPP.

A large plant that grows in a warm, swampy environment and faces substantial herbivory most likely

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. Compare net secondary production in year 4 with year 3. How did net secondary production change? What could have driven this change? What is unusual about net secondary production in year 4? How could heterotrophs survive under these conditions?

What is the correct ranking in total global NPP of the following terrestrial biomes, from highest to lowest?

Refer to the figure. Which figure best represents the changes in NPP during succession in the typical forest ecosystem?

Which of the following would likely have the greatest proportion of productivity going into its own respiration?

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 GPP of the forest?

By means of a process called _______, some bacteria can use forms of _______ as electron donors to take up CO₂ and convert it to carbohydrates.

Not all consumed matter is incorporated into the biomass of a heterotroph. A heterotroph's growth is determined by its _______ secondary production, which equals ingestion minus _______.

NPP is generally lower at 25° latitude than it is 10° closer to the equator or 10° closer to the poles. What is the best explanation for this phenomenon?

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. How did energy production and/or use change when comparing year 1 and year 3? What effect did these changes have on the relationship between GPP, NPP, and NEE?

In experiments measuring the NPP of grassland ecosystems over time and at different sites, Lauenroth and Sala discovered that