Nutrient Cycling Flashcards
What is nitrogen mineralization and immobilization? Under what kind environment, one process will have a advantage on another process?
yes
Simply diagram and interpret the nitrogen cycle in terrestrial ecosystem. (like Figure 9.6)
YEs
Microbes involve most part of nitrogen cycle. How they response to increased nitrogen deposition?
yes
What are the relative magnitudes of atmospheric inputs and mineralization from dead
organic matter in supplying the annual
nitrogen uptake by vegetation?
yes
If Earth is bathed in dinitrogen gas, why is
the productivity of so many ecosystems
limited by availability of nitrogen? What is
biological nitrogen fixation? What factors
influence when and where it occurs?
Yes
What are the mechanisms by which nitrogen is deposited from the atmosphere into
terrestrial ecosystems?
yes
What are the major steps in the mineralization of litter nitrogen to inorganic
forms? What microbial processes mediate
each step and what are the products of each
step? Which of these processes are extracellular and which are intracellular?
yes
What ecological factors account for differences among ecosystems in annual net
nitrogen mineralization? How does each of
these factors influence microbial activity?
yes
What determines the balance between
nitrogen mineralization and nitrogen immobilization in soils
yes
. What factors determine the balance
between plant uptake and microbial uptake
of dissolved organic and inorganic nitrogen
in soils?
yes
How do ammonium and nitrate differ in
mobility in the soil? Why? How does this
influence plant uptake and susceptibility to
leaching loss?
yes
What is denitrification and what regulates
it? What are the gases that can be produced,
and what are their roles in the atmosphere?
yes
What is the main mechanism by which
phosphorus enters ecosystems?
yes
What factors control availability of phosphorus for plant uptake? Why is phosphorus availability low in many tropical soils?
yes
Why are mycorrhizae so important for
plant acquisition of phosphorus?
yes
