52. Ecosystems

Which of these ecosystems has the lowest net primary production per square meter?a. a salt marshb. an open oceanc. a coral reefd. a tropical rain forest

Fill in the blanks in the table below summarizing terrestrial ­nutrient cycles.

True or False: Most of the net primary productivity that is consumed is used for growth by primary consumers. Explain.

Which of the following is the longest-lived reservoir for carbon?a. atmospheric CO2b. marine plankton (primary producers and consumers)c. fossil fuelsd. wood

Nitrifying bacteria participate in the nitrogen cycle mainly bya. converting nitrogen gas to ammonia.b. releasing ammonium from organic compounds, thus returning it to the soil.c. converting ammonium to nitrate, which plants absorb.d. incorporating nitrogen into amino acids and organic compounds.

If you applied a fungicide to a cornfield, what would you expect to happen to the rate of decomposition and net ecosystem production (NEP)?a. Both decomposition rate and NEP would decrease.b. Neither would change.c. Decomposition rate would increase and NEP would decrease.d. Decomposition rate would decrease and NEP would increase.

Devegetation has what effect on ecosystem dynamics?a. It increases belowground biomass.b. It increases nutrient export.c. It increases NPP.d. It increases soil organic matter.

Which of the following has the greatest effect on the rate of chemical cycling in an ecosystem?a. the rate of decomposition in the ecosystemb. the production efficiency of the ecosystem's consumersc. the trophic efficiency of the ecosystemd. the location of the nutrient reservoirs in the ecosystem

If the GPP of a grassland is 5000kcal/m2/year and 55 percent is used up by cellular respiration, what is the NPP?a. 2250kcal/m2/yearb. 2750kcal/m2/yearc. 5000kcal/m2/yeard. need more data

Which of the following was a result of the Hubbard Brook watershed deforestation experiment? (A) Most minerals were not recycled within the intact forest ecosystem. (B) Calcium levels remained high in the soil of deforested areas. (C) Deforestation decreased water runoff. (D) The nitrate concentration in waters draining the deforested area became dangerously high.

Explain why decomposition rates in a field in Nebraska would differ from the decomposition rates in a field in the Amazon. How do decomposers regulate nutrient availability in ecosystems?

The Hubbard Brook watershed deforestation experiment yielded all of the following results except which of the following?a. Most minerals were recycled within a forest ecosystem.b. Calcium levels remained high in the soil of deforested areas.c. Deforestation increased water runoff.d, The nitrate concentration in waters draining the deforested area became dangerously high.

The web of life refers to the .a. evolutionary relationships among living organisms;b. connections between species in an ecosystem;c. complicated nature of genetic variability;d. flow of information from parent to child;e. predatory effect of humans on the rest of the natural world

Which of the following would be considered an example of bioremediation?a. adding nitrogen-fixing microorganisms to a degraded ecosystem to increase nitrogen availabilityb. using a bulldozer to regrade a strip minec. reconfiguring the channel of a riverd. adding seeds of a chromium-accumulating plant to soil contaminated by chromium

Why are the open oceans nutrient poor? Why are coastal areas and intertidal habitats relatively nutrient rich?