Energy and Nutrient Cycling II

What is the role of detritivores?

- Detritivores are decomposers that break down dead matter (like animals and plants)

- They play a major role in the cycling of nutrients (as they make molecules from high level consumers available for plants (primary producers)

What are the major factors of decomposition?

- Temperture (more = faster rate)

- Moisture (more = faster rate)

- Nutrient availability (more=faster rate)

How is decompistions effected in different biomes?

Tropical biomes

(warm & high moisture lvls)

- Decompistion occurs at a rapid rate

- This means there is less nutrients in the soil because they get washed away in a faster rate

- More exposed bedrock

Colder biomes

(cold and lower mostiture lvls)

- Decompisition happens slower due to microbes working slower (decompisition stops at -14˚c)

- More nutrients in soil as there is more time for the pummus to build up

Why are nutreint cycles called biogeochemical cycles?

Bio=apart of biological systems (eg cell function)

Geo=occurs over a geographic timescale (eg rocks weathering)

Chemcial=nutrients are chemical compounds that cycle round

Cycle=it is a cycle

What are the two characteristics that define the main reservoirs of elements?

- Whether they contain organic or inorganic matter (organic vs inorganic)

- Whether these materails are directly available for use by organisms ( available vs unavailable)

Organic molecules occur when other molecules bond to carbon

What are the 4 resourviours of resources?

Organic, available

- Living organisms (eg animals & plants)

- Detritus

Organic, unavailable

- Peat, coal, oil

Inorganic, available

- Atmosphere (eg. CO2, N)

- Water

- Soil

Inorganic, unavailable

- Minerals in rocks

What are the four major factors to consider in the cycling of water, carbon, nitrogen, and phosphorus?

- Each chemical's biological importance

- Forms in which each chemical is available for use

- Major resorvures for each chemical

- Key processes driving movement of each chemical throughout it's cycle

Describe the water cycle

- Essentail for all organisms

- Needed for cellular function

- Movement of water happens via evaporation, condensation (clouds), precipitation (rain) and percolation (water movement through soil)

Describe the carbon cycle

- Nearly all life forms are made out of carbon organic molecules

- Plants convert CO2 into organic molecules that are made avaiable to consumers

- Carbon only available from primary producers

- Carbon is released when organisms breath

- Carbon resourviours are made out of fossil fuels, forests etc.

^ carbon resourviours are needed to sustain carbon equilibrium, if they are damaged/taken away then there is more carbon in the atmosphere which changes the enviroment of the atmosphere

Describe the nitrogen cycle

- Nitrogen is available for plants as NH4 (ammonia) and NO3 (nitrate) (nitrate is main one tho)

- Enters the plants via nitrogen fixing bacteria

- Ammonification makes NH4 molecules from NH2

- Nitrofication is when NH4 is broken down into nitrate

- The air is made up of around 70% nitrogen

- All organisms need nitrogen to survive

Describe the phospherous cycle

- Phospherous makes up phospholipids and ATP

- Mainly found in rocks of marine origin

- Has a cycle that is a long geographical time span

^ sedimentation, takes a long time (20, 000-100, 000 years)

How has human activity determentally impacted the enviroment of the earth?

- Higher levels of carbon due to burning fossil fuels, leads to increase in temp. due to carbon particles letting a lot of sunlight through

- More nitrogen in the biosphere and terrisitrially

^ terisitrally leads to eutrophication

- Deforestation leads to water lose and a loss of clouds due to transpiration (important for inland terristiral ecosystems)

- Deforested areas have more nitrogen run off due to lack of roots

- Water scarcity