Exam 22: Nutrient Supply and Cycling

All other things being equal, herbivores generally must consume _______ food than carnivores in order to meet their nutritional needs. The reason is that plant material, per gram of carbon, contains _______ nitrogen than animal material does.

In stratified temperate lakes, mixing is most likely to occur in the

Which of the following is not a primary source of nitrogen in marine ecosystems?

All nutrients are ultimately derived from

Which intervention would most likely lead to an increase in detritivore activity in warm, moist soils?

Which sequence best describes the order of soil horizons in well-developed soil from top to bottom?

When studying terrestrial ecosystems, ecologists commonly focus on an area that is drained by a single stream, which is called a(n)

Refer to the table and the figure. Table 1 Figure 2 You are studying a river that has been dammed to form a reservoir. You have compiled data collected on this system over time (Table 1 and Figure 2). -Suppose you are expanding your research to focus on the entire drainage basin in this area, including the reservoir, the former river channel, and the area where the river flows into the ocean. Answer the following questions: a) What is the term that best describes the unit of study your work is focused on? b) What type of ecosystem is likely to occur where the freshwater and marine systems meet? c) How would you expect dam construction to initially impact the area where fresh water and marine systems meet? d) Based on the data in Figure 2 from 1990-2010, what could have been done to counteract the effects of the dam on the estuary?

Which statement about nitrogen fixation is false?

Refer to the table. According the table, which of the following statements about the elemental composition of organisms is true?

Which statement about nutrient cycling is true?

Suppose two agents are introduced into soil: one that results in an increase in nitrification and another that results in an equal addition of denitrification. Compared to the soil before, the combination of equal amounts of nitrification and denitrification in the soil would result in a net increase in

Suppose that the mean residence time of calcium in a section of soil is 6 years and the mean rate of input is 30 kilograms per year. If rates of input and output as well as the total pool size have remained roughly constant, what is the expected size of the total pool of calcium in the soil?

In order for most organisms to use the nitrogen in the atmosphere, dinitrogen gas must be

Refer to the figures. Based on Gough's study and others, which figure shows the most likely relationship between plant species richness and soil acidity?

_______ is the key process by which nutrients in detritus are made available as soluble organic and inorganic compounds that can be taken up by other organisms.

Refer to the figure. Figure 1 You are studying a river in its natural state, unaffected by human activities. Your data are graphed in Figure 1. You began collecting data at the source of the river ("0 km" on the figure) and continued to sample the river every 1 km. - Use your knowledge of nutrient cycles to answer the following questions: a) Why is the nutrient cycle in a lake depicted as a circular cycle, while in a river it is depicted as a spiral? b) In general, when would you expect the structure of the nutrient cycle of a river to most closely resemble that of a lake? In the case of your data, which location in the river most closely fits the conditions seen in a lake?

What is the input of calcium into a catchment if the flow of water into the catchment is 150 liters per day and the concentration of calcium is 0.04 mg/liter?

Refer to the figure. Based on research by Vitousek and colleagues, an Ohi'a tree that grows about 2.6 mm in diameter a year when fertilized with nitrogen and phosphorous would most likely be living on a Hawaiian island approximately _______ years old.

Refer to the figure. -Which statement best explains the downward trend that follows the peak of each curve?