Last mastering wooooo Flashcards
Which of the following is (are) major sources of the carbon dioxide now being added to the atmosphere in excess of the amount taken out by plants?
a. loss of soil organic matter
b.destruction of natural forests
c. burning of fossil fuels
d. all of the above
e. none of the above
d. all of the above
The process of ________ releases soluble nitrogen as the result of the breakdown of nitrogen-rich organic compounds.
mineralization
The thaw of permafrost will release a lot of carbon to the atmosphere because
permafrost soils contain a lot of soil organic matter and when they thaw, microbes can decompose this carbon to CO2 and, or CH4
Under natural vegetation, about 60 to 90% of soil organic matter is ________.
in the passive fraction
Which form of nitrogen can be taken up by the roots of plants that do NOT live in symbiosis with N-fixing microorganisms?
ammonium and nitrate
True or false: Well-aerated soils enriched with organic amendments can help reduce the methane load in the atmosphere.
true
One would expect well-drained soils to have the highest organic matter contents where the climate is ________.
cool and humid
Soil organic matter consists of ________.
a. living organisms and cells
b. dead tissues and wastes
c. identifiable biomolecules
d. polymerized, non-identifiable molecules
e. all of the above
e. all of the above
Which one of the following reservoirs contains the largest amount of the world’s carbon?
soil
Alcohols, methane and organic acids of various kinds often accumulate as a result of ________ decomposition of residues in soil.
anaerobic
True or false: Soil organic matter consists mainly of complex microbially produced supermolecule polymers known as humic substances.
false
According to the Representative Concentration Pathway (RCP) 8.5 (formerly known as the Business-as-Usual scenario), global surface temperature at the end of this century will be ________________ at the beginning of this century.
about 3-5 degrees celsius higher than
According to the Representative Concentration Pathway (RCP) 8.5 (formerly known as the Business-as-Usual scenario), global surface temperature at the end of this century will be ________________ at the beginning of this century.
about 3-5 degrees celsius higher than
Nitrogen is a component of which essential plant compounds
a. enzymes
b. DNA
c. proteins
d. chlorophyll
e. all of the above
e. all of the above
True or false: As decomposition of added organic material proceeds, the C/N ratio in the remaining undecomposed material steadily increases.
false
Which of the following is a greenhouse gas contributed to the atmosphere by soils?
carbon dioxide, methane, and nitrous oxides
How large are the annual fluxes of CO2 between terrestrial ecosystems and the atmosphere (photosynthesis and ecosystem respiration)?
about 120 Pg C per year
True or false: Denitrification is a major output of nitrogen from terrestrial ecosystems to the atmosphere. This leaky pathway produces a powerful greenhouse and ozone-layer-depleting gas. The process is most rapid when soils are warm, moist, and aerated.
false
True or false: Denitrification is a major output of nitrogen from terrestrial ecosystems to the atmosphere. This leaky pathway produces a powerful greenhouse and ozone-layer-depleting gas. The process is most rapid when soils are warm, moist, and aerated.
false
Soils with thick horizons consisting mainly (> 30% by weight) of organic matter and that form in topographic depressions or low-lying places usually belong to the order ________.
histosols
What is the Haber-Bosch process?
process for creating fertilizers
As a group, fungi are _____.
decomposers
Fungi release digestive enzymes into their _____.
surroundings
Basidia produce spores by a process known as _____.
meiosis
___ is the anaerobic oxidation of ammonium. It converts ammonium to nitrogen gas using nitrate as an electron acceptor.
annamox
air pollutant forms of nitrogen
nitric oxide
ammonia
water pollutant forms of nitrogen
nitrate
greenhouse gas forms of nitrogen
nitrous oxide
not a reactive form of nitrogen
nitrogen gas
Which form of nitrogen can be taken up by the roots of plants that do NOT live in symbiosis with N-fixing microorganisms?
ammonium and nitrate
Nitric oxide is
NO
Nitrate is
NO3-
Ammonium is
NH4+
Urea is
CH4N2O
Nitrate is
NO3-
Ammonia is
NH3
Nitrogen (or dinitrogen) gas is
N2
Nitrous oxide is
N2O
Organic nitrogen is
R-NH2
NH4+ or NO3- –> R-NH2
immobilization
NH4+ or NO3- –> R-NH2
Immobilization
R-NH2 –> NH3 –> NH4+
mineralization
CH4N2O –> NH4+ –> NH3
volatilization
NO3- –> NO2- –> NO –> N2O –> N2
denitrification
N2 –> NH3 –> R-NH2
n2 fization
NH4+ –> NO2- –> NO3-
nitrification
In metapopulation theory, what does P stand for?
proportion of patches occupied
Island biogeography theory predicts that a 10-fold increase in area results in
a doubling of species number
Which of the following increase connectivity between patches?
corridors
True or false: The initial floristic composition hypothesis proposes that the process of succession at any site is dependent on which species arrive first.
true
What would likely be true when P = 0.9?
rate of extinction would be high
Which of the following is an example of an allogenic change that drives succession?
seasonal changes in temperature, photoperiod, and light intensity
Which of the following is an autogenic change?
decreased light due to canopy cover
True or false: as a patch increases in size, the ratio of interior to edge increases
true
When a forest gradually merges into a grassland over a wide area, the border between the two landscape patches is referred to as a(n)
ecotone
Beach grass colonizing newly formed sand dunes is
primary succession
The intermediate disturbance hypothesis predicts
intermediate disturbance will increase diversity
Two patches are connected by a corridor but a species does not utilize it. This is an example of
low functional connectivity
Where the edge of one patch meets another is referred to as
a boundary
With increasing forest area in a patch, what is more likely to occur?
interior species
Which of the following is considered a ruderal species?
one that colonizes well
Plants adapted to edge environments tend to be
intolerant of shade and tolerant of dry conditions
Chronosequences are useful because one can
view several seres in one region
Which is an example of secondary succession?
a farmer allows an agricultural field to return to native grassland
