ECOSYSTEM ECOLOGY L26 Flashcards
I. Ecosystem productivity - CC E production - SEQ, HD E flow II. E transfer between trophic levels - CC, SEQ, HD E transfers III. Biogeochemical cycles - CC, SEQ cycles
1
Q
ecosystem
A
- all living organisms in an area and abiotic environment
- E flow is linear
- nutrients are cycled
2
Q
trophic levels
A
- groups of species based on main source of E/nutrition
3
Q
primary producers
A
- autotrophs
- photosynthetic
- build own biomass
- plants (land), algae and cyanobacteria (aquatic)
4
Q
consumers
A
- heterotrophs
- primary: herbivores
- secondary: carnivores that consume herbivores
- tertiary: carnivores that consume other carnivores
5
Q
detritivores
A
- E from dead organic mater
- break down, recycle organic materials back into environment
6
Q
primary production
A
- amount of light E converted to chemical E by autotrophs during a given time
- GPP
- (totally primary production in an ecosystem) - (amount of E converted to chemical E)
7
Q
NPP
A
- E that remains in tissues after cellular respiration
- (GPP) - (autotrophic respiration)
- 1/2GPP
- represents E available to next trophic level
8
Q
assimilation
A
- total E taken in
- used for growth, reproduction, respiration
- excludes E lost in feces
9
Q
net secondary production
A
- chemical E in consumers
- food converted to biomass and reproduction
10
Q
production efficiency
A
- how much E taken in incorporated as biomass
- 1-3% for birds and mammals and 10% for fish - always low
11
Q
trophic efficiency
A
- % of production transferred from one trophic level to the next
- E lost
- not all organic matter consumed
- usually about 10%
- 90% of available E (net secondary production) not transferred
12
Q
biogeochemical cycles
A
- movement of matter through biotic and abiotic components of ecosystems
13
Q
water cycle
A
- essential for all organisms
- evaporation: liquid – gas
- transpiration: movement from ground – air through plants
- condensation: water vapor – clouds
- precipitation: atmosphere – ground
14
Q
carbon cycle
A
- organic molecules
- absorbed via photosynthesis
- released via respiration, combustion, volcanism
15
Q
phosphorus cycle
A
- nucleic acids, phospholipids, ATP
- weathering/erosion adds phosphate to soil
- incorporated into biomass by producers
- released via excretion or decomposition
16
Q
nitrogen cycle
A
- amino acids, nucleic acids
1. nitrogen fixation: abiotic – biotic, N2 – NH3 or NH4+, makes N available, nitrogen fixing bacteria in soil or water
2. nitrification: NH3 or NH4+ – nitrate, nitrifying bacteria in soil
3. assimilation: NH3, NH4+, nitrate – amino acids, nucleic acids, plants absorb reactants from soil, assimilate into organic compounds, N now locked into organisms
4. ammonification: organic N – ammonia, waste products contain N, available for nitrification or assimilation
5. denitrification: nitrate – N2, returns N to atmosphere
