Chapter 6: Forest Ecosystem Ecology Flashcards
Energy flow goes from this to this
High quality sunlight to low quality heat
Ecological efficiency averages about this much
10%
This is the rate at which producers convert light to chemical energy
Primary productivity
This is the total rate of energy fixation
Gross primary productivity
This is GPP minus producer respiration and is the energy available to the rest of the ecosystem
Net primary productivity
NPP = GPP - this
Plant respiration
What percent of sunlight is NPP?
1-2%
Among forest biomes, which have the highest NPP?
Tropical forests
What are six constraints on leaf-level photosynthesis?
Photosynthetically active radiation (PAR); Air/soil temperatures; Available water; Humidity; CO2 concentration; Nutrients
What nutrient in particular is a constraint on leaf-level photosynthesis?
Nitrogen
What is actual evapotranspiration?
Actual water lost to evaporation and transpiration
Does actual evapotranspiration increase with increase in temperature?
Yes
Does actual evapotranspiration decrease with increase in moisture?
No
This measures the total area of leaves
Leaf area index
This increases leaf area index
Light deficit
This lowers leaf area index
Water/nutrient deficit
These describe movements of chemicals through an ecosystem
Nutrient cycles
What are the two components of nutrient cycles?
Pools and fluxes
These store nutrients for some period
Pools
These are movements of nutrients between pools
Fluxes
This is the time nutrients spend in a pool
Residence time
What are four types of nutrient inputs?
Wet/dry atmospheric deposition; Mineral weathering; Nitrogen fixation; Nutrient mineralization
What are two sources of nitrogen fixation?
Nitrogen-fixing bacteria and lightning
What is a source of nutrient mineralization?
Release from SOM