WorksheetsGlobal Environmental Change Impacts to Soil Ecology
Total questions: 10
Worksheet time: 5mins
Name
Class
Date
1.
Which of these N cycling processes is most likely to be inhibited by N deposition?
a)
N fixation
b)
Nitrification
c)
N mineralization
d)
Denitrification
2.
Which of these N cycling processes is most likely to be accelerated by N deposition?
a)
All of these are likely to be accelerated by N deposition
b)
Nitrification
c)
N mineralization
d)
Denitrification
3.
If a plant exudes sugars into an extremely low nutrient soil, rhizosphere microbes are likely to respond by
a)
nitrifying N
b)
fixing N
c)
mineralizing N
d)
immobilizing N
4.
High concentrations of ____ in soil and surface waters are the best indicator of N saturation.
a)
nitrate
b)
ammonium
c)
organic N
d)
dinitrogen
5.
Elevated N is most likely to ______ plant litter decay rates early during the process of decomposition and to _____ plant litter decay rates late during the process of decomposition.
a)
increase, decrease
b)
decrease, increase
c)
increase, increase
d)
decrease, decrease
6.
In order to increase growth rates under elevated CO2, plants require
a)
nutrients
b)
ozone
c)
high temperatures
d)
high light levels
7.
Human activities have increased N inputs into natural ecosystems by a factor of approximately __.
a)
1.5
b)
2
c)
3
d)
4
8.
Under elevated N, the C:N ratio of plant litter is most likely to
a)
change unpredictably
b)
not change
c)
decrease
d)
increase
9.
Nutrient mineralization is the
a)
mineral-catalyzed conversion of insoluble organic nutrient forms to soluble nutrient compounds
b)
precipitation of soluble mineral nutrient compounds out of solution
c)
microbial enzyme-catalyzed conversion of organic nutrient forms to mineral nutrient compounds
d)
adsorption of charged nutrient compounds onto mineral surfaces
10.
The compound that gets nitrified is
a)
nitrate
b)
dinitrogen
c)
ammonium
d)
organic N
100 %
