Nutrient Cycles L14 Flashcards
what is the nutrient cycle like
not a closed system
where does nutrient cycling occur
Nutrient cycling occurs at global level
through geological processes, such as,
atmospheric circulation, erosion and
weathering
what is geochemical cycles
atoms of earth are in flux and occur in different places at different times
what is a biogeochemical cycle
path atoms take between biotic (biosphere) and abiotic (lithosphere, atmosphere, and hydrosphere) world, and back again
what do biogeochemical cycles involve
natural processes that recycle nutrients in various chemical forms
what is the biogeochemical cycle effect
are usually localized in effect
what do plant do to calcium in bones
calcium in your bones are mobilized by plants
what helps plants mobilise calcium
microbes from minerals in rocks that were once formed in the sea by sedimentation from calcite shells of microscopic marine creatures
what is the in which all the chemistry of life takes place
water
what is a source of hydrogen in photolysis
water
what splits water
plant cells
what reconstitutes water
biota
what effect water residence times in various reservoirs
abiotic factors, such as increased/decreased solar energy
reservoir examples
oceans
atmospheres
of the 50-70 elements found in living things how many are cycled
more than thirty are cycled through environment by biogeochemical cycles
what are the six most important biogeochemical cycles
carbon hydrogen oxygen nitrogen phosphorus sulphur
where do organisms get nutrients and energy from
Organisms derive nutrients and energy from their habitat
what are the energy pyramid feeding relationships
producers
consumers
decomposers
what are producers
provide fundamental energy source; only organisms that can produce organic compounds by assimilating inorganic carbon from atmosphere;
Photosynthetic organisms
termed autotrophs
what are consumers
feed on other living
organisms and obtain energy from
breaking chemical bonds; primary,
secondary, tertiary…
what are decomposers
primarily microbes, break down and absorb organic matter of dead organisms; recycle organic matter into inorganic minerals and gases, mineralise nutrients
what are terrestrial habitats made of
organic compartment consists of living organisms and their detritus
what is in the available nutrient compartment
available-nutrient compartment consists of nutrients held to surface of soil particles or in solution
what does the third compartment consist of
nutrients held
in soils or rocks that are unavailable directly to living
organisms
what does the fourth compartment consist of
air which can be found in atmosphere or in ground
what is the main path for nutrients in soil
from the soil through the roots of producers
what is soil like
a dynamic, complex ecosystem with a vast array of microbes, animals, and plants
what are lichens
symbiotic associations between a fungus and a cyanobacterium or green algae produce acids that releases
minerals from rocks
what is humus
rich moist layer of soil
containing plant and animal debris
being decomposed by microbes
what is rhizosphere
zone of soil around plant roots, fungi and protozoa
what is mycorrhizae
symbiotic organs formed between fungi and certain plant roots
what are aquatic habitats like
Often stratified, limited mixing of layers
what mixes aquatic habitats
Winds mix waters within epilimnion during summer
what isolates mixing to the surface of water
thermocline isolates
when does turnover in aquatic habitats occur
winter months
what does turnover of aquatic habitats cause
breakdown of thermocline
allowing mixing and nutrient flow
what is the primary reservoir
atmosphere acts for carbon dioxide (CO2), oxygen (O2) and water (H2O)
how can inorganic compounds be exchanged with biota
inorganic compounds can be exchanged directly with biota through processes of photosynthesis and respiration
what is the most abundant gas in atmosphere
nitrogen 78%
where carbon tied up
most in sedimentary rocks but the portion that circulates is what sustains life
how much carbon is there estimated to be
around 40,000 gigatons
where is most of the carbon
93% in ocean
how is carbon recycled
through ecosystems via photosynthesis, respiration, and fermentation of organic molecules, limestone decomposition and methane production
how long does the carbon cycle for atmosphere take
3 years
how long does the carbon cycle for soil take
25-30 years
how long does the carbon cycle for oceans take
1,500 years
what dominates terrestrial ecosystems photosynthesis
plants
what dominates aquatic ecosystem
phototrophic
microbes
what are the basic elements of life
Carbon, hydrogen and oxygen
makes up 98% od plant biomass
how do CO2 and O2 enter biota
atmosphere
example of producers
photosynthetic autotrophs