Lecture 37 - Environmental Nutrient Cycles Flashcards
Describe relationships between producers, consumers, and decomposers
Producer = autotroph
Consumer = heterotroph
Decomposer = heterotroph but specializes in decomposition
What are the two sources of energy input for an ecosystem?
Radiant energy and chemical energy
What adaptation required for oligotrophic environments?
I. Growth rate very slow
II. efficient transporters to concentrate nutrients
What adaptation required for environments crowded with other organisms?
I. produce bacteriocins
II. produce quormones/anti-quormones
What adaptation required for environments with rapidly flowing water?
I. aerobes and phototrophs
II. “super” biofilm
What adaptation required for soil environments?
I. form microcolonies
Example of microbial succession
fermentation in dairy products and sauerkraut
Carbon cycle
Aerobic/Anaerobic
Autotrophs take CO2 and reduce it to glucose
Heterotrophs take glucose and oxidize to CO2
Side branch
Methanogens reduce CO2 to CH4
Methane-oxidizing bacteria convert it back to CO2
Nitrogen cycle
Nitrogen fixation: reduce N2 to NH4
Nitrification: oxidize NH4 to NO2/NO3
Denitrification: reduce NO3 to N2
Anammox: oxidize NH4 and reduce NO2 to N2
Sulfur cycle
Photosynthetic bacteria oxidize H2S to S or SO4
Sulfur oxidizing bacteria oxidize H2S or S to So4
SO4 incorporated into plants and bactera
Sulfate reducing bacteria reduce SO4 to H2S
What are the basics of how fixed nitrogen is incorporated into plant tissues?
Bacteroids turn into root nodules on legume roots
How do biogeochemical cycles occur in the deep ocean without solar energy input?
thermal vents release hydrogen sulfide (H2S) which is used as an electron source
Name 2 ways in which symbiotic fungal associations can increase plant root surface area
wrap around outside of plant root cells
live inside plant root cells
Describe a lichen (looks and composition)
fungal filament which acts like a root
it get nutrients from photosynthetic partner
