Photosynthesis and Carbon Cycling

Ecology 2 - VOCAB ONLY

Production

accumulation of carbon compounds in biomass - increases through growth

Gross Primary Production (GPP)

total biomass made through photosynthesis by autotrops

Net Primary Production (NPP)

GPP minus biomass loss due to respiration of plants

Secondary production

accumulation of biomass by heterotrophs

pool

reserve of the element (organic or inorganic)

ex: CO2 in atmosphere

Flux

transfer of element from one pool to another

EX: photosynthesis

Carbon sink

if photosynthesis is greater than cell respiration

carbon source

if cell respiration is greater than photosynthesis

Coal

325-250 million years ago

Peat

last 10,000 years

Biomass

wood in trees last few thousand years

keeling curve

• graph of atmospheric CO2 levels

• long term growth

• annual fluctuations - down in summer due to increased photosynthesis

aerobic respiration and photosynthesis

• autotrophs give heterotrophs oxygen from phtoosynthesis

• heterotrophs give autotrophs CO2 from cell respiration

• interdependence

recycling of elements

• limited utilities of key chemical elements

• decomposers play key role - break down so can be reused

• carbon, hydrogen, oxygen, nitrogen, phosphourus, etc.

photosynthesis

conversion of light energy to chemical energy by chloroplast by creating glucose that can be used for cell respiration (two main phases)

light dependent reactions

occur in thylakoid membranes of chloroplast

light independent reactions (calvin cycles)

occur in stroma of chloroplast

chlorophyll

main light absorbing pigment in plants

Absorption spectrum

light absorbed by different pigments at different wavelengths

action spectrum

rate of photosynthesis at each wavelength

how to test rate of photosynthesis

• CO2 concentration - counting bubbles and baking soda

• light intensity - syringe and leaf discs

• varying temperature - water bath - CO2 up, pH down

FACE

• must be outside to stimulate ecosystem

• prediction of consequences of increased CO2 levels in atmosphere

• at high light intensity and temperatures photosyntheis is limited by CO2

• when temp and light are constant and CO2 is up photosynthesis and growth are up