2.3 Flows of Energy and Matter Flashcards
song on fate of solar radiation as it reaches Earth.
“So-lar rays come from the sky
Some re-flect and some pass by
Nine per-cent off Earth does bounce
Nine-teen from the clouds we count
Three from dust-y air up there
Clouds ab-sorb a ti-ny share
Se-ven-teen gets trapped in dust
For-ty-nine shines through — it must!”
pathways of energy through an ecosystem:
- conversion of light energy to chemical energy
- transfer of chemical energy from one trophic level to another with varying efficiencies
- overall conversion of ultraviolet and visible light to heat energy by an ecosystem
- reradiation of heat energy to the atmosphere
how much energy is available to plants on the surface of the earth
1-4%
how much of sunlight is reflected back to space?
Of the energy reaching the Earth’s surface, about 35% is reflected back into space by ice, snow, water and land.
how to calculate ecological efficiency
(energy used for growth (new biomass)/ energy supplied x 100
productivity definition
the conversion of energy into biomass over a given period of time
primary productivity definition
the gain by producers (autotrophs) in energy or biomass per unit per unit time. Either gross or net productivity
gross primary productivity definition
The total amount of energy fixed (converted to sugars) by plants through photosynthesis.
net primary productivity definition
The remaining energy after respiration, stored as biomass.
- This represents the energy available to consumers (herbivores & decomposers).
NPP calculation
NPP = GPP - R
Gross Secondary Productivity definition
total energy or biomass assimilated by consumers
(also known as assimilation)
GPP calculation
food eaten - fecal loss
secondary productivity definition
the biomass gained by heterotrophic organisms (animals), through feeding and absorption, measured in units of mass or energy per unit area per unit time.
NSP definition
the gain by consumers in energy or biomass per unit area per unit time through absorption after allowing for respiratory losses
NSP calculation
NSP = GSP - R
Maximum sustainability yield definition
the amount of biomass that can be extracted without reducing natural capital of the ecosystem.
- equal to NPP or NSP of a system
- harvesting above = reduction of natural capital = unsustainable
carbon cycle transformations
- fossilisation
- combustion
- respiration
- photosynthesis
carbon cycle transfers
- herbivores feeding on producers
- carnivores feeding on herbivores
- decomposers feeding on dead organic matter
- co2 dissolving from atmosphere in rainwater oceans
carbon cycles storages organic
- organisms
- forests
nitrogen cycle transformations
- nitrogen fixation
- nitrification
- death and decomposition
- denitrification
- assimilation
nitrogen fixing bacteria explanation
transforms nitrogen gasses found in roots of plants into ammonium ions
- bacteria converts ammonium into nitrites and nitrates
dentrifying bacteria explanation
converts ammonium and nitrate ions into nitrogen gas
nitrogen cycle transfers
- herbivores feeding on producers
- carnivores feeding on herbivores
- decomposers feeding on dead organic matter
- plants absorbing nitrates through their roots
- excretion
Discuss the impacts of human activity on the carbon cycle
- burning fossil fuels/fire adds co2 into atmosphere
- deforistation -> takes away important carbon store
increased atmospheric co2 by about 40%
