Biosphere

Geobiology

how physical, chemical, and biological processes influence each other

Abiotic components

energy, nutrients, water

Biotic components

prokaryotes and eukaryotes

LUCA

last universal common ancestor

Metabolism

chemical processes that occur within a living organism to maintain life

Oxidation

loss of electrons or increase in oxidation state

Reduction

gain of electrons or decrease in oxidation state

Photosynthesis

carbon + water → glucose + oxygen

Primary production

building living material by fixing carbon

Autotrophs

primary producers; build organic matter by fixing carbon; provide most organic carbon for the biosphere

Heterotrophs

cannot fix carbon to form their own organic compounds; consume organic compounds/primary producers

Photoautotrophy (oxygenic)

use H2O as an electron donor to produce oxygen as a waste product

Photoautotrophy (anoxygenic)

don’t use H2O as an electron donor; use sulphur, iron, hydrogen, etc.

Chemoautotrophy

obtain energy by utilizing reactions between naturally occurring chemicals

Photoheterotrophy

use light as an energy source

Chemoheterotrophy

use energy derived from oxidation of chemicals

Energy transfer between trophic levels

10%

Gross primary production

total photosynthetic output

Net primary productivity

rate at which biomass accumulates; GPP-respiration

Essential elements for life

carbon, nitrogen, oxygen, phosphorus, hydrogen, sulphur

Carbon residence time

mass of substance in reservoir/flux in or out of reservoir

Terrestrial/marine carbon cycle atmosphere

760 GtC

Terrestrial carbon cycle plant biomass

560 GtC

Terrestrial carbon cycle soil

1500 GtC

Marine carbon cycle surface ocean

1000 GtC

Marine carbon cycle deep ocean

38000 GtC

Carbonate compensation depth

depth where calcium carbonate dissolves due to high pressure and low pH

Fast carbon cycle

rapid exchange between surface reservoirs

Surface reservoirs

atmosphere, ocean, biosphere

Slow carbon cycle

slow exchange with the geosphere, contains 99% of all carbon

Biological pump

transfer of carbon from the surface to deep water

Coupling

linked parts of a system

Feedback

a self-perpetuating mechanism of change responding to perturbations

Controls on primary productivity in terrestrial biomes

light, temperature, precipitation

Controls on primary productivity in marine biomes

light, key nutrient availability

Nitrogen

makes up 78% of the atmosphere, essential for nucleic acids, limiting nutrient

Hadean & Archean

emergence of LUCA, single-cellular life, stromatolites, cyanobacteria

Proterozoic

Great Oxidation Event; eukaryotes, multicellular life, complex animals emerge

Phanerozoic

Cambrian explosion, colonization of land, rise of mammals

Carboniferous

vast coal deposits, high oxygen levels, large insects