Nutrient Cycles Flashcards
Name the three different carbon inputs into a aquatic ecosystem
Atmosphere, (Co2 diffusion and carbonic acid inorganic carbon) . Autochthonous (macrophyte material, from inorganic carbon inputs), Allochthonus, external inputs (Run off, leaves falling into lake etc)
What are humic compounds?
A form of dissolved organic carbon. They are created during incomplete decomposition of plant material (microbes). Can turn water dystrophic if levels are high enough.
Give two examples of humic compounds
humic and fulvic acids
Give examples of non-humic compounds.
carbohydrates, proteins, urea, pigments. These are utilized quickly by organisms.
Will surface runoff be more or less humic then ground water run off?
Surface water will have fewer humic compounds as it will be more oxygenated then ground water runoff and complete decomposition is more likely to occur which does not result in humic compound production. Ground water has low 02 and humic compounds will be higher.
In the carbon cycle describe three carbon inputs
Inorganic diffusion of carbon dioxide and carbonic acid from weathering of rock. Autochthonous ( producers transform inorganic carbon into OC). Allochthonous inputs e.g run off, material falling into lake.
In the carbon cycle describe a method of carbon recycling and breakdown.
Predator prey interactions (heterotrophy) is an example of carbon being transferred within the system. Respiration and decomposition is an example of carbon breakdown.
Where does carbon cycle in an aquatic ecosystem?
At all levels in aerobic and anaerobic conditions
What is CH4?
methane
What is H2CO3?
Carbonic acid
What role do methanogenic bacteria have in the methane cycle?
They break down carbon dioxide and produce methane in the absence of oxygen.
What do methanogenic bacteria do?
In anoxic conditions they reduce carbon dioxide and form methane, which then diffuses into oxic zone
What do methanotrophic bacteria do?
In oxic conditions they oxidize methane and prevent release into the atmosphere.
What is the process that methanogenic bacteria are responsible for?
methanogenesis (reducing CO2 and produces CH4).
What is the process that methanotrophic bacteria are responsible for?
methanotrophy (oxidizes CH4 and prevents release into atmosphere).
Name 2 natural source of methane.
Wetlands: because of plant aerenchyma methane bypasses methanotrophy and enters straight into atmosphere. Melting of permafrost where trapped methane from ancient bogs is being released into atmosphere.
What form of Nitrogen dominates in anoxic water?
NH4 ammonium
What forms of nitrogen dominate in oxic water?
nitrite and nitrates
What type of nitrogen do producers use?
NHx and NOx
Name three types of nitrogen inputs.
N2 diffusion and nitric acid from rain
Name 2 allochthonous inputs of nitrogen
terrestrial material (animal tissue) and fertilizer run off
