Ecology- UKY Chapter 19

Animals gain phosphorus, in the form of phosphates, by _____.

-ingesting other animals that contain phosphorus compounds -ingesting plants that contain phosphate

In a stream ecosystem, nutrient retentiveness is _____ related to spiraling length, meaning that as one value increases, the other value decreases.

-inversely

Denitrification_______.

-is energy releasing and is carried out by bacteria

One example of how vertebrate animals may affect nutrient cycling in an aquatic environment is through excretion. If an animal such as a catfish, has low N:P ratios, they are likely to excrete _______ phosphorus compared to organisms with higher N:P ratios.

-less

Nitrogen can enter the nutrient cycle through fixation by living organisms or through the energy and pressure generated by____.

-lightning

The main sources of phosphorus in the ecosystem are:

-marine sediments -mineral deposits such as rocks

Atmospheric forms of carbon include carbon dioxide and _____ gas.

-methane

In a study performed by Gallardo and Merino to investigate the effects of litter chemistry on decomposition, the mesh bags contained holes 1mm large. This allowed aerobic _____ activity and small soil invertebrates to aid in decomposition.

-microbial

The conversion of nutrients such as phosphorus from an organic form to an inorganic form is called________.

-mineralization

Plants are assisted in their uptake of phosphorus from the soil due to their interaction with mutualistic _____ fungi.

-mycorrhizal

Bison tend to feed on grasses that are ____ prairie dog mounds because the grasses are ____ in nitrogen content.

-near; higher

Animals may gain nutrients from ingestion of plants. When these animals die, the animals decompose. This decomposition leads to the production of ammonium. Eventually, bacteria convert ammonium to nitrate in the process called_____.

-nitrification

Research results (Mellillo and colleagues) from two temperate forests suggest that higher decomposition rates of leaf litter in a North Carolina forest compared to a forest in New Hampshire may be due to greater availability of the nutrient ____ in the soil.

-nitrogen

Pocket gophers were shown to affect the ____ cycle by bringing nutrient-______ soil to the surface, in the Cedar Creek Natural History Area.

-nitrogen; poor

The use, transformation, movement, and reuse of nutrients in ecosystems is called______.

-nutrient cycling

Phosphorus is essential to living organisms. For example, phosphorus is the main component of cell membranes when it is combined with lipids to form ________.

-phospholipids

Sedimentary rocks especially rich in ___ are mined for fertilizer.

-phosphorus

Concerning the movement of phosphorus through the environment____.

-phosphorus can move from rivers into oceans

Carbon dioxide is removed from the atmosphere by the process of ____.

-photosynthesis

Which of the following are true?

-plants growing in high-nutrient ecosystems grow at a faster rate than those in low-nutrient -Plants growing in low-nutrient ecosystems allocate more resources to root growth compared to shoot growth

Results from research on decomposition rates show_____.

-plants with higher toughness: nitrogen rations loss less mass

As shown in the Gallardo and Merino study, elevated moisture levels have a _____ effect on leaf decomposition.

-positive

Work done by Whicker and Detling found that _____.

-prairie dog grazing results in young grass tissues high in nitrogen content

In the study done by Meyer and Likens on the movement of phosphorus in the Bear Brook ecosystem, inputs to the ecosystem included_____.

-precipitation -seeps

Which of the following is correct concerning the movement of carbon between organisms and the environment?

-respiration returns carbon to the atmosphere in the form of carbon dioxide

Which of the following molecules in living organisms do NOT contain phosphorus?

-ribose sugar

Which of the following could explain the high level of nitrogen retention in suburban watershed areas?

-riparian areas -actively growing lawns

Nutrient cycling can be affected by animals transporting nutrients from one ecosystem to another. An example of this are the Pacific salmon that spend most of their lives at sea. However, after spawning in streams and ____, the salmon die and their carcasses are utilized by other organisms

-river

One way humans overcome nitrogen limitation to plant growth is to ____ crops capable of nitrogen fixation with crops that have high nitrogen needs. These crops add ammonium to the soil.

-rotate

Example of human (anthropogenic) sources of nitrogen enrichment include_____.

-runoff from agricultural land into waterways -burning of fossil fuels

In suburban areas, one contributor to increased nitrate input to stream ecosystems can be the presence of ______ systems that can discharge nitrate

-sanitary

When a specific nutrient is absorbed faster than it is released into the environment, this type of nutrient pool is called a nutrient ______.

-sink

Areas that may have high levels of Co2 uptake (vs. output) that are reducing the predicted effects of increased burning of fossil fuels are referred to as being the "missing carbon____."

-sinks

Examples of carbon sinks, locations where carbon is relatively unavailable for long periods of time, include _____.

-soil -carbonate rock -fossil fuels

Work done my McNaughton, Ruess, and Seagle, indicate that large grazing animals, such as bison ______.

-speed up nutrient cycling in an ecosystem

Because water currents move nutrients downstream, Webster coined the term nutrient _____ to describe stream nutrient dynamics.

-spiraling

During years of low streamflow, Bear Brook_____.

-stores phosphorus

Decomposition rate is mainly affected by moisture levels, the chemical composition of litter and the environment, and _______.

-temperature

In a river or stream where nutrient spiraling is occurring, nutrients may be used many times (cycled) before leaving a stream system, when _____

-the spiraling length is short

Which of the following molecules found in living organisms do NOT contain nitrogen? A. proteins, such as hemoglobin B. chlorophyll C. cellulose D. nucleic acids, such as DNA

C

T/F: In a study of suburban watersheds, it was found that both nitrogen inputs and outputs were high

False

In the equation for nutrient spiraling, S=VT, T represents_____.

- average time to complete a nutrient cycle

Pocket gophers may _____ plant diversity by increasing the _____ of nutrient availability in the soil.

- increase; heterogeneity

Scientists currently believe that the "missing" carbon sinks that are moderating the increased CO2 input to the atmosphere (due to burning of fossil fuels) are ______.

- northern and tropical forests

Results from research on decomposition rates forest show ______.

- the toughness of plant leaves is inversely related to decomposition rates

In a study done by Meyer and Likens, it was shown that in the Bear Brook ecosystem, there were annual pulses of phosphorus import and export. During which season occurred the greatest phosphorus import?

-Autumn

The results of experiments done by Suberkropp and Chauvet on the effects of nitrate on decomposition in freshwater had results that were consistent with the study done by the lead author_____ on how soil nitrogen content affects decomposition.

-Melillo

The term nutrient spiraling was coined by the scientist named Jack______.

-Webster

Fungi and bacteria release nitrogen as ammonium through the process called_____

-ammonification

Phosphorus (or phosphate) can enter aquatic environments____.

-as runoff from land following rain storms -as runoff from fertilized farm fields -as runoff from land following the melting of snow

In the experiment performed by Likens and Bormann on the effects of deforestation on nutrient cycling, inputs to the stream include weathering of granite ____ and precipitation

-bedrock

An example of a nutrient source would be______.

-burning of fossil fuels that add carbon dioxide to the atmosphere

Eutrophication_____.

-can lower water oxygen content

Which of the following molecules found in living things always contain carbon?

-carbohydrates -lipids -proteins

Nitrogen in the atmosphere is_______.

-converted to others forms by cyanobacteria -converted to other forms by algae -the main pool of nitrogen on the environment

Nitrogen fixation____.

-converts N2 to ammonium

In the nitrogen cycle, nitrogen is returned to the atmosphere through the process of _______.

-denitrification

Nutrient enrichment of an aquatic ecosystem that can be due to human activities is called______. It can result in water quality problems.

-eutrophication

During years of high streamflow, Bear Brook______.

-exports of phosphorus were greater than inputs

Many detritivores reingest nutrients such as nitrogen by eating their _____.

-feces

Because plant growth is dependent o nitrogen, and fixed nitrogen is relatively low in abundance, humans add _____ to the soil to increase crop production.

-fertilizer

Phosphorus inputs to Bear Brook were evenly divided about the three size fractions of phosphorus. However, the majority of phosphorus exports were____.

-fine particulates

In a nutrient cycle, nutrients move between pools due to nutrient____.

-flux

The burning of _____ fuels has become a major source of atmospheric carbon dioxide.

-fossil

Gessner and Chaivet determined that higher lignin content in plant materials inhibits colonization by_____ that are mainly responsible for decomposition of leaves in stream habitats.

-fungi

In the Hawaiian ecosystem, the Myrica tree was introduced. Compared to the native trees in the Hawaii Volcanoes National Park, it______

-has leaves that decompose at a higher ratef

Research done by Tayku, Alba, and Kitayama indicates that higher concentrations of phosphate in the soil are associated with _______.

-higher rates of decomposition -increased rates of leaf litter fall

In major river ecosystems, such as the Mississippi, Thames, and the Amazon, the single variable that appeared to explain most of the variation in nitrate concentration and export was ______ population density.

-human

Because higher evapotranspiration rates _______ the rate of decomposition, decomposition in temperate ecosystems is usually _____ than in tropical environments.

-increase; lower

Increased population densities are associated with____

-increased nitrogen enrichment of river ecosystems

Burning of fossil fuels has _____ the concentration of CO2 in the atmosphere since the industrial revolution, despite oceans acting as carbon__________

-increased; sinks

Deforestation_____.

-increases the levels of nitrate loss from deciduous forest ecosystems

In a study done on nitrate export in streams draining in Baltimore County, Maryland. It was shown that land use affects the average nitrogen concentration. While all area received similar amounts of atmospheric input, which of the following is true concerning the differences between the areas?

-urban sanitation systems can leak nitrogen, but the leaks are typically controllable

In a study done, nitrate export in streams draining watersheds in Baltimore County, Maryland, it was shown that land use affects the average nitrogen concentration. Rank the average nitrogen concentrations in the streams from lowest to highest. (lowest at the top)

1. forested area 2. urban area 3. suburban area 4. agriculture area

One form of deforestation, which involved removing all trees from an area is called______. When this occurs, nitrate losses from the environment increase.

clear-cutting