ENERGY FLOW THROUGH TERRESTRIAL ECOSYSTEMS Flashcards
(22 cards)
1
Q
Subsolar Point
A
- Is the latitude on Earth where the sun’s rays hit exactly vertically at noon. This is where the intensity of incident radiation will be greatest (highest W/m2)
2
Q
Solar Angle of Incidence
A
- Angle of light that hits the surface of the Earth
3
Q
Seasonality
A
- Occurs because of the tilt of the Earth’s axis results in movement of the subsolar point
4
Q
Photosynthesis
A
- Is the process by which energy from the sun, in the form of PAR, is harnessed to convert CO2 into simple sugars, and oxygen is released as a by-product
- Formula: Energy + 6CO2 + 6H2O → C6H12O6 + 6O2
5
Q
Cellular Respiration
A
- Energy can be released through the breakdown of carbohydrates
- Formula: C6H12O6 + 6O2 → 6CO2 + 6H2O + Energy (in ATP)
6
Q
Primary Productivity
A
- The rate at which radiant energy from the sun is converted by photosynthesis into organic compounds (i.e., biomass)
7
Q
Gross Primary Production (GPP)
A
- The total rate of photosynthesis or energy assimilation by primary producers (autotrophs). Some energy acquired through GPP will be used during respiration (R) or lost as heat
8
Q
Net Primary Production (NPP)
A
- The rate of energy storage in plant biomass after losses due to respiration: NPP = GPP – R
9
Q
Primary Production
A
- The creation of energy-rich organic compounds by producers (plants, algae) through photosynthesis or chemosynthesis.
Ex: Plants converting sunlight into glucose.
10
Q
Secondary Production
A
- The storage of organic matter by organisms other than primary producers
Ex: Those that consume net primary production or consume other heterotrophic organisms
11
Q
Consumption Efficiency
A
- The percentage of total productivity at a given trophic level that is actually consumed by organisms one trophic level up
- What enters the digestive tract of organisms one trophic level up
12
Q
Assimilation Efficiency
A
- The percentage of food energy that is assimilated across the gut wall
13
Q
Production Efficiency
A
- The percentage of assimilated energy that is incorporated into new biomass
- Varies according to taxonomic class (e.g., invertebrates are more efficient than vertebrates)
14
Q
10% Rule
A
- Only 10% of the energy stored at a given trophic level is transferred to the next highest trophic level
15
Q
Ecological Energy Pyramid
A
- The quantity of energy flowing into a trophic level decreases the higher up a food chain you go
- Hence, a plot of productivity (or energy) at each successive trophic level produces a tapering pyramid
16
Q
Ecological Biomass Pyramid
A
- When less energy is available at a given trophic level, creation of biomass will also be lower
- Hence, a plot of biomass at each successive trophic level also produces a tapering pyramid
17
Q
Grazing Food Chain
A
- Starts with living plants (producers) eaten by herbivores, then passed to carnivores (e.g., Grass → Grasshopper → Frog → Snake).
18
Q
Detrital Food Chain
A
- Starts with dead organic matter, broken down by decomposers, then consumed by detritivores (e.g., Dead leaves → Earthworm → Bird).
19
Q
Light Compensation Point
A
- The rate of carbon loss is greater than the rate of uptake
20
Q
Light Saturation Point
A
- The value of PAR is beyond which photosynthesis no longer increases, even if more light is added. The plant has reached its maximum photosynthetic capacity.
21
Q
Photoinhibition
A
- When plants adapt to shaded environments, and photosynthesis declines as light level exceeds saturation
22
Q
C, N, K, and P Used for Within Plants
A
- Carbon © - Provides a structural basis for plants
- Nitrogen (N) - Plays a key role in enzyme functions of plants
- Potassium (K) - Is involved in stomatal osmoregulation
- Phosphorus (P) - Is involved in energy transfer in plant cells
