Forest Ecosystem Function Introduction Flashcards
Use of Carbon
Half to build tissue, other half to fuel cellular processes (converted back into CO2)
What is biomass ?
(standing crop) weight of organic material per area at a given point in time…..represents stored energy
What is production ?
amount of biomass (energy) produced in an area over a certain time period
What is productivity ?
production per unit area per unit of time, it’s a RATE
What is gross production ?
total biomass (energy or carbon)
Net production ?
gross production - losses to respiration
Primary production ?
energy captured by primary producers (autotrophs)
Secondary, tertiary production ?
energy into consumers, detritivores
Gross Primary Production ?
Total Production of carbon by 1st producers (= all carbon produced by photosynthesis in a forest)
Net Primary Production (NPP) ?
Gross Primary Production (GPP) - autotrophic respiration (respiration of all plants)
Net Ecosystem Production (NEP) ?
NPP - Heterotrphic Respiration (RH) (respiration of all-non autotrophs)
Why is Carbon important ?
- energy currency of all ecosystems
–> plant (autotrophic) production is the base of almost all food/trophic webs
–> underlies all ecosystem goods and services - plant C cycling, controls atmospheric CO2 concentrations
–> 3 to 4 times as much in terrestrial ecosystems as the atmosphere
–> forests account for 80% of global plant biomass and 50% of global terrestrial productivity - C is fundamental to soil processes
–> Belowground resources are a primary control over all ecosystem ecosystems (SOM : biological, physical and chemical functions).
Importance of soils for carbon storage ?
Soils store the most terrestrial organic C.
Central concepts for understanding C cycling in ecocystems ?
- Pools (storage) vs fluxes (flows) of C
–> LIve and dead (detrital biomass)
–> Above and belowground - Law of conservation of Mass
Relation between inputs, outputs and storage ?
Inputs = Outputs + Difference of storage
Major forest carbon pools ?
- Live aboveground
–> Shrubs
–> Trees
–> Other plants - Live belowground
–> Roots - Deadwood
–> Standing dead trees (snags)
–> Downdd logs - Litter
–> Leaves
–> Needles
–> Small branches - Soil organic matter
–> dead and decayed biomass
–> plant material and insects
Factors influencing the amount and proportion of carbon in each forest carbon pools ?
- Age of the forest
- Species of trees making the forest
- Natural and human disturbances
- Soil characteristics (texture and drainage)
- Past agricultural land-use history
Size of C pools in different forests ?
High storage in aboveground pool in tropical forests (mostly moist and wet), not a lot in boreal dry.
High storage in belowground pool in boreal moist.
Type of autotrophs (self-feeding) ?
Photoautotrophs: sun energy converted into sugars, higher plants, algae
Chemoautotrophs: sulfur, iron, hydrogen bacteria; nitrifying bacteria.
Heterotrophs ?
Use organic sources of carbon/energy
Consumers: primary (herbivores), secondary/tertiary (omnivores, carnivores), Detritivores (saprotrophs).
Principle of photosynthesis ?
Energy storing. In chloroplast.
Requires CO2 (carbon dioxide) and water, produces sugar and oxygen.
PAR = photosynthetically active radiation of sunlight.
Transfer of energy/matter from inorganic carbon (CO2 gas) to organic carbon (glucose)
Principle of aerobic respiration ?
releases energy. in mitochondria
Requires oxygen and glucose, releases CO2 and ATP (energy) and heat. Breakdowns of sugars to provide energy.
What is production ecology ?
study of energy transfers and storage in the ecosystem.
- complex carbon molecules store energy in their bonds
- C constitutes about 50% of dry mass of all organisms
- carbon is the currency
- energy stored or transferred often expressed in biomass units.
What are the inputs, the transfers within the ecosystem and the outputs?
inputs : autotrophs
transfers within the ecosystem : trophic web to dead organic matter (DOM)
outputs : respiration
