Primary Productivity Flashcards
What is biomass?
the mass of living material
present at any time, expressed as grams
per unit area or volume
What is productivity?
the rate of production of
living material per unit time per unit area
or volume
What is primary productivity?
productivity due to
Photosynthesis
What are secondary consumers?
productivity due to
consumers of primary producers
What is a food chain?
linear sequence showing
which organisms consume which other
organisms, making a series of trophic levels
What is a food web?
more complex diagram showing feeding relationships among organisms, not restricted to a linear hierarchy
What is the equation for photosynthesis?
6CO2 + 6H2O → C6H12O6 + 6O2
What are autotrophs?
use pigments to capture the energy in sunlight
What is cellular respiration?
biological fuels are oxidised in the presence of an inorganic electron acceptor, such as oxygen, to drive the bulk production of adenosine triphosphate, which contains energy.
What factors effect primary production?
- light
2.nutrients
What is Nutrients in Marine environments?
particularly nitrate (most important) and phosphate
What are reasons a marine environment might not get enough sunight?
: Based on weather e.g., cloudy days
Seasonally: e.g., winter at temperate/high latitudes
Spatially: e.g. suspended sediment at surface
Self-shading: When dense phytoplankton at surface limit light availability to organism living below
What does primary production depend on?
light intensity and depth of light penetration
Where is the highest light intensity in the ocean?
The epipelagic zone
Which is has more percentage of light?
Coastal waters or open waters
open waters
Where can most nutrients reach in the ocean?
the photic zone, any other zone recomposes nutrients called remineralizing
Which geographic parts of the marine world ave the highest primary production?
Continental shelf and open-ocean upwelling
Which geographic parts of the marine world have the lowest primary production?
Central ocean, gyre centers
What are some terrestrial sources for nutrients?
River input
Aeolian deposition
What are some atnospheric sources for nutrients?
Dissolution of gases, particulates
N2: Nitrogen fixation
What are some marine sources for nutrients?
Nutrient remineralization: Breakdown of organic material into inorganic constituents via decomposition
The Microbial Loop
Nutrient upwelling from depth
Mixing
What is Gross primary productivity GPP?
total carbon fixed during photosynthesis
What is Net primary productivity NPP?
total carbon fixed during photosynthesis minus that part which is respired - NPP is what is available to higher trophic levels.
What is the RadioCarbon Technique?
add known amount of 14C-labeled bicarbonate to solution with phytoplankton
after a time: filter phytoplankton, and do counts of 14C-emitted β particles in a scintillation counter.
14C is taken up more slowly than much more common stable isotope 12C.
What is the satellite approach?
Satellites can use photometers specific to wavelength to measure chlorophyll.
Need ground truthing to get relationship between chlorophyll concentration and primary production
varies with region
