Question 1

Experiments on how soil fertility limits terrestrial NPP demonstrate that _____ constrain(s) NPP.

Accepted Answer

Experiments have shown that both nitrogen and phosphorus play a role in limiting terrestrial net primary productivity (NPP). In some cases, both nutrients need to be added for NPP to increase significantly, indicating that they are co-limiting factors. While micronutrients may also be important for plant growth, they are not typically the primary limiting factor for NPP.

Question 2

Iron is lost from oceans when it combines with _____ and precipitates.

Accepted Answer

The answer of Iron is lost from oceans when it...

Question 3

Aquatic ecosystems can be limited by silicon because

Accepted Answer

Silicon sinks faster than nitrogen or phosphorus, which can limit its availability in the upper layers of aquatic ecosystems where it is needed by organisms like diatoms.

Question 4

Which of the following is NOT a low-productivity aquatic ecosystem?

Accepted Answer

Coral reefs are known for their high productivity due to the diverse and dense populations of marine life they support.

Question 5

Aquatic NPP is primarily limited by

Accepted Answer

Aquatic NPP is primarily limited by light as photosynthesis cannot occur without sufficient light availability. Other factors such as temperature, fertility, and salinity can also impact aquatic NPP, but light is the primary limiting factor.

Question 6

Which of the following ecosystems has the highest levels of primary productivity?

Accepted Answer

The answer of Which of the following ecosystems has the...

Question 7

What are the major drivers of NPP?

Accepted Answer

The two major drivers of NPP are temperature and precipitation as they are the main factors affecting plant growth and photosynthesis. Fertility and pH can also be important factors but are typically less influential overall.

Question 8

Which of the following is NOT a high-productivity aquatic ecosystem?

Accepted Answer

The open ocean is not a high-productivity aquatic ecosystem because it has low nutrient levels and primary productivity compared to other ecosystems. The other options listed (estuary, coral reef, salt marsh) are all considered high productivity ecosystems due to their high nutrient levels and diverse array of photosynthetic organisms.

Question 9

Terrestrial NPP is greatest in _____ ecosystems, and aquatic NPP is greatest in _____ ecosystems.

Accepted Answer

Terrestrial ecosystems, such as tropical rainforests, have the highest rates of net primary productivity due to warm temperatures and abundant rainfall. Aquatic ecosystems, specifically coastal ecosystems, have high rates of productivity due to the mixing of nutrients from the land and the sea. Open-water, or pelagic, ecosystems have lower rates of productivity due to nutrient limitation. Polar ecosystems have low rates of productivity due to extreme temperatures and a short growing season. Therefore, choice A is the best answer.

Question 10

Which of the following ecosystems has the lowest levels of primary productivity?

Accepted Answer

Desert scrub ecosystems typically have very low levels of rainfall and high temperatures, leading to low levels of primary productivity.

Question 11

Between latitudes of 30° N and 30° S, NPP is primarily constrained by

Accepted Answer

NPP in the latitudinal range of 30° N to 30° S is primarily limited by precipitation. This is because this region experiences tropical rainforests and savannas, where the climate is warm and wet, fostering the growth of vegetation. However, if there is a lack of precipitation, then plant growth and photosynthesis will be limited, leading to a decrease in NPP.

Question 12

A terrestrial ecosystem has an NPP of 850 g C/m²/y and respiration of 1.25 kg C/m²/y. What is the ecosystem GPP in kilograms per meter squared per second?

Accepted Answer

The answer of A terrestrial ecosystem has an NPP of...

Question 13

What nutrient fertilization has been discussed as a way to counteract global warming? How would the nutrient(s) affect global warming, and what are the drawbacks, if any?

Accepted Answer

The answer of What nutrient fertilization has been discussed as...

Question 14

In addition to nitrogen and phosphorus, what nutrients can limit productivity in the open ocean?

Accepted Answer

Silicon and iron are two additional nutrients that can limit productivity in the open ocean. Silicon is essential for the growth of diatoms, which are phytoplankton that contribute significantly to the ocean's primary production. Iron is necessary for the growth of cyanobacteria, another important group of phytoplankton. Both of these nutrients are often present in low concentrations in the open ocean, limiting the growth and productivity of these key primary producers.

Question 15

NPP varies with _____ around the world.

Accepted Answer

NPP (Net Primary Productivity) varies with latitude or location on the Earth's surface. This is largely due to the availability of sunlight and temperature for photosynthesis, which decreases as one moves towards the poles, resulting in less NPP. Elevation and soil type can also affect NPP, but their effects are secondary to latitude. Longitudinal variation in NPP is negligible as it is related to climate and vegetation patterns, which are primarily influenced by latitude.

Question 16

Compilation of data from many experiments on nutrients and NPP in marine ecosystems shows that ecosystems with hard bottoms are generally limited by _____, while soft-bottomed ecosystems are generally limited by _____.

Accepted Answer

Hard-bottomed marine ecosystems are generally limited by nitrogen, while soft-bottomed ecosystems are often limited by both nitrogen and phosphorus.

Question 17

(Figure 20.9) The figure shows that as mean annual temperature increases, net primary productivity also increases. Net primary productivity increases with mean annual precipitation until approximately 3 meters of precipitation, after which productivity declines. Why does this decline occur?

Accepted Answer

The answer of  (Figure 20.9) The figure shows that...

Question 18

What is the primary reason that estuaries and coral reefs are so productive?

Accepted Answer

Estuaries and coral reefs are both located in nutrient-rich areas where freshwater and saltwater mix, leading to high nutrient levels in the water. This promotes the growth and diversity of primary producers such as algae and seagrasses, which in turn support diverse communities of herbivores and carnivores.

Question 19

In fertilization experiments in a lake in Ontario, which of the following nutrients were shown to have the greatest limitation on productivity?

Accepted Answer

Phosphorus was shown to have the greatest limitation on productivity in the fertilization experiments. This is because phosphorus is often the limiting nutrient in freshwater systems, as it is less abundant than nitrogen and carbon, which are more easily taken up by primary producers. Limiting nutrients are those that are in short supply and therefore limit the growth and productivity of organisms in an ecosystem.

Question 20

Silicon is used primarily by

Accepted Answer

Silicon is an essential nutrient for the growth and maintenance of the cell walls of diatoms, which are a type of algae. Other organisms, such as zooxanthellae and zooplankton, do not require silicon in the same way that diatoms do.

Quiz 20: Movement of Energy in Ecosystems

Experiments on how soil fertility limits terrestrial NPP demonstrate that _____ constrain(s) NPP.

Iron is lost from oceans when it combines with _____ and precipitates.

Aquatic ecosystems can be limited by silicon because

Which of the following is NOT a low-productivity aquatic ecosystem?

Aquatic NPP is primarily limited by

Which of the following ecosystems has the highest levels of primary productivity?

What are the major drivers of NPP?

Which of the following is NOT a high-productivity aquatic ecosystem?

Terrestrial NPP is greatest in _ ecosystems, and aquatic NPP is greatest in _ ecosystems.

Which of the following ecosystems has the lowest levels of primary productivity?

Between latitudes of 30° N and 30° S, NPP is primarily constrained by

A terrestrial ecosystem has an NPP of 850 g C/m²/y and respiration of 1.25 kg C/m²/y. What is the ecosystem GPP in kilograms per meter squared per second?

What nutrient fertilization has been discussed as a way to counteract global warming? How would the nutrient(s) affect global warming, and what are the drawbacks, if any?

In addition to nitrogen and phosphorus, what nutrients can limit productivity in the open ocean?

NPP varies with _____ around the world.

Compilation of data from many experiments on nutrients and NPP in marine ecosystems shows that ecosystems with hard bottoms are generally limited by _, while soft-bottomed ecosystems are generally limited by _.

(Figure 20.9) The figure shows that as mean annual temperature increases, net primary productivity also increases. Net primary productivity increases with mean annual precipitation until approximately 3 meters of precipitation, after which productivity declines. Why does this decline occur?

What is the primary reason that estuaries and coral reefs are so productive?

In fertilization experiments in a lake in Ontario, which of the following nutrients were shown to have the greatest limitation on productivity?

Silicon is used primarily by

Quiz 20: Movement of Energy in Ecosystems

Experiments on how soil fertility limits terrestrial NPP demonstrate that _____ constrain(s) NPP.

Iron is lost from oceans when it combines with _____ and precipitates.

Aquatic ecosystems can be limited by silicon because

Which of the following is NOT a low-productivity aquatic ecosystem?

Aquatic NPP is primarily limited by

Which of the following ecosystems has the highest levels of primary productivity?

What are the major drivers of NPP?

Which of the following is NOT a high-productivity aquatic ecosystem?

Terrestrial NPP is greatest in _____ ecosystems, and aquatic NPP is greatest in _____ ecosystems.

Which of the following ecosystems has the lowest levels of primary productivity?

Between latitudes of 30° N and 30° S, NPP is primarily constrained by

A terrestrial ecosystem has an NPP of 850 g C/m2/y and respiration of 1.25 kg C/m2/y. What is the ecosystem GPP in kilograms per meter squared per second?

What nutrient fertilization has been discussed as a way to counteract global warming? How would the nutrient(s) affect global warming, and what are the drawbacks, if any?

In addition to nitrogen and phosphorus, what nutrients can limit productivity in the open ocean?

NPP varies with _____ around the world.

Compilation of data from many experiments on nutrients and NPP in marine ecosystems shows that ecosystems with hard bottoms are generally limited by _____, while soft-bottomed ecosystems are generally limited by _____.

(Figure 20.9) The figure shows that as mean annual temperature increases, net primary productivity also increases. Net primary productivity increases with mean annual precipitation until approximately 3 meters of precipitation, after which productivity declines. Why does this decline occur?

What is the primary reason that estuaries and coral reefs are so productive?

In fertilization experiments in a lake in Ontario, which of the following nutrients were shown to have the greatest limitation on productivity?

Silicon is used primarily by

Quiz 20: Movement of Energy in Ecosystems　

Terrestrial NPP is greatest in _ ecosystems, and aquatic NPP is greatest in _ ecosystems.

A terrestrial ecosystem has an NPP of 850 g C/m²/y and respiration of 1.25 kg C/m²/y. What is the ecosystem GPP in kilograms per meter squared per second?

Compilation of data from many experiments on nutrients and NPP in marine ecosystems shows that ecosystems with hard bottoms are generally limited by _, while soft-bottomed ecosystems are generally limited by _.