Biosphere 2 Flashcards
What are some of the limits to life?
Temperature
Pressure
Light
pH
Salinity
Water activity
UV
Radiation
What are the upper and lower limits of temperature for life?
-15C to 122c
What is the maximum pressure life can survive in?
1,100 atmosphere
What is the pH range in which life can survive?
0-12.5
We can we notice about chlorophyll concentration throughout year?
centred around equator with strong upwelling of deep nutrients
How many elements are essential for life?
24
What are the macro nutrients/ the big six?
C, H, O, P, N, S
Why are micronutrients important?
they can be the limiting factor dependent on environment
What is growth limited by in terms of nutrient?
not by the total amount of resources available but by the scarcest resource
What is Liebigs law/ law of minimum?
element with the lowest concentration in the environment relative to its demand will limit growth
What is bioconcentration?
Organisms are selective in their uptake of elements and nutrients
What is an example of biconcentration?
Marine algae concentrate Fe (100,000x), N, P, Mn (10,000-100,000x) and Zn, Ni, Cu, Cd, Al (1000-10,000x) above seawater concentrations
What is bioaccumulation?
organisms excrete less of an element than they consume
What is biomagnification?
bioaccumulation gets exacerbated up the food chain
What factors form part of biogeochemical cycles?
Reservoir- mass/ volume
Flux- mass per unit time/ movement
Residence time how long in reservoir
What is the timescale for biological carbon cycling?
Short term- 10s of years
What is the timescale for medium term carbon cycling?
up to 1000s of years
What is medium term carbon cycling dominated by?
storage organic chemicals in the woody tissue of trees, in forest soils, and in other organic sediments
What is the timescale of long term carbon cycling?
up to millions of years
What type of processes is the long term carbon cycling dominated by?
geological processes
What geological processes form the long term carbon cycle?
Carbonate rock production
Return carbon to atmo by weathering, metamorphism, subduction and volcanism
What is nitrogen like as a gas?
relatively unreactive
What happens to nitrogen as it moves between reservoirs?
reduced and oxidised
What form of nitrogen is needed for plant, algae and bacteria uptake?
nitrate ion
or
ammonium ion
What is nitrogen fixation?
process of converting N2 (gas) into biologically useful forms
How can nitrogen fixation occur?
Specialised bacteria
Lightning strike
Where is phosphorus mainly stored?
lithosphere and biosphere
How is phosphorous stored in the hydrosphere?
phosphate
What do photosynthetic algae do to earths surface?
change the colour and albedo
What does the roughness of vegetation on land affect?
flow of wind, weather, and climate
What flow between land and atmosphere is mediated by plants?
water
How do plants interact with the lithosphere?
Increase evaporation and decrease runoff. Roots stabilize soil, affecting rates of erosion
What is co-evolution?
How life affects and is affected by the physical and chemical environment
