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