Nutrient Cycling Flashcards
Decomposition rate is influenced by
Temperature
Moisture
Chemical composition of matter
______ generally increases nutrient loss from ecosystems
Disturbances
Main nutrient cycles are
P
C
N
The carbon cycle is closely tied to _____
Energy flow
-respiration
-photosynthesis
-sediment
-combustion
Nitrogen fixation
Bacteria convert N2 gas into NH3, which is rapidly converted to ammonium NH4, or into NO3-
Mineralization
Decomposers take organic compounds and change them into NH4+
Nitrification
NH4+ to NO2-
-Nitrosomonas and Nitrosococcus
And then
NO2- to NO3-
-Nitrobacter and Nitrococcus
Phosphorous cycle
-Geological uplifting
-weathering of phosphate from rocks
-runoff
-mycorrhiza
-phosphate in soil
-plants
-animals
-decomposers
-phosphate in soil
-leaching
-phosphate in solution
-detritus settling to bottom
-sedimentation=new ricks
Decomposition
Breakdown of large organic molecules into simpler, smaller molecules, eventually inorganic molecules
-bacteria
-fungi
-detrivores
When do rates of decomposition increase
With moisture and temperature
When do rates of decomposition decrease
Decrease as toughness increases (lignite and cellulose because of an increase in N content
What causes seasonal fluctuations of CO2
Photosynthesis in Northern hemisphere
-more CO2 in winter as there are less trees photosynthesizing
_______ increases nutrient loss from ecosystems
Disturbance
Result of Hubbard brook experiment
Deforested/ clear cut areas had extremely higher amounts of calcium, potassium and nitrates during rain seasons due to leeching and erosion than non clear cut areas
13x normal rate
-reduction in evapotranspiration (because of lack of leaves)->more precipitation to ground water and more leeching.
-no trees to absorb nutrients released by decomposition
In the Hubbard brook experiment, watersheds were taken to represent…..
Ecosystems
In the southern hemisphere, north-facing slopes are _____ than south-facing slopes
Warmer
Because of the coriolis effect, winds from the equator to the poles are deflected towards the…..
East
About 80% of the solar energy that strikes the surface of the ocean is absorbed within the first _____ meters
10
What is the most extended biome in Canada
Boreal forest
CAM and C4 photosynthesis are similar in that….
They increase water use efficiency
In an aquatic plant, the boundary layer of water around a leaf _______ the rate of diffusion of CO2 from ______
Decreases
Water to the mesophyll
What is the value of Q10 for O2 consumption of the relation between O2 consumption and temperature is linear and O2 consumption is three-fold for a temperature increase of 20°C
1.5
