The Biosphere Flashcards
What is the biosphere?
- The biosphere is all
ecosystems on Earth - Includes both
terrestrial (land) and
marine (ocean)
ecosystems
**SeaWiFS **was launched in 1997 and died in 2010. It was designed to see chlorophyll in
the water but also sense the NDVI on land. It has 1km spatial resolution and 8 bands.
Photosynthesis
is the process by which plants convert solar energy, carbon dioxide and water into carbohydrates (sugar) and oxygen.
Energy + CO2 + H2O > C6H12O6 + O2
Photosynthesis is the fundamental basis for energy flows in ecosystems and the biosphere
Why monitor the biosphere?
The biosphere (through photosynthesis) absorbs carbon dioxide from the atmosphere
Crucial to monitor the biosphere so we can understand carbon cycles thus analsyng how the carbon cycle is affecting our climate and ecosystem
Photosynthesis: Cycling Carbon
solid carbon = energy
photosynthesis > converts carbon into organic living matter> waste from living organisms or just die > creates a pile of dead organism and waste > decompose/fossil fuil> we dig up and burn it to create energy
ways for carbon to come back to the atmosphere as gas from its solid state :
-plant respiration
-animal respiration
-auto and factory emission
Metrics for Monitoring the Biosphere
- Productivity
-GPP & NPP
-What affects productivity? - Carbon sinks and sources
- Biomass
Productivity in the biosphere
Primary production can be measured as:
- Gross primary production (GPP) is the total amount of energy created by plants
- Net primary production (NPP) is the amount of energy stored in the plant after accounting for plant respiration
NPP = GPP - R (respiration)
Productivity is affected by climatic factors:
- light,
- air temperature,
- precipitation
- carbon dioxide concentration
Productivity and temperature
- Productivity and
respiration are affected
by climate variables - High temperature
induces stress in plants -
Respiration increases
and** net photosynthesis
decreases** with higher
temperature
after a peak at about just under 20 degrees celsius and then it starts to decrese
after 20 degrees celsius respiration increses
gross photosynteshis just continues to increse
slide 13
Climatic Factors Affecting Productivity
Light
* Increases photosynthesis until saturation
Carbon dioxide
* Increases photosynthesis until saturation
Water
* Increases photosynthesis until saturation
Temperature
* Increases photosynthesis but levels off at higher temperature
* And net photosynthesis will start to decrease at higher temperatures
* Plants will get stressed at higher temperature and require much higher respiration
What Can I See? Case Study: Biosphere
just like how when our temperature increses we breath more (like on a run), we get more tired and we produce less energy (cause we are tired!)
Carbon Sink vs. Source
- Sink: absorbs more carbon from the atmosphere than it releases (photosyntesis)
- Source: releases more carbon to the atmosphere than it absorbs
- By measuring carbon sinks and sources we can monitor carbon
transfer and carbon storage in the biosphere - i.e. how much carbon is in the atmosphere vs. stored in the forests
- And how much is that changing year to year
examples of carbon sinks
carbon sinks are good we dont want a lot of carbon relesed in the atmosphera
- helthy forest
examples of carbon sources
not to good/not a lot of photosintesis
- forest cut down
- forest fire
- insect infestation
Measuring biomass
Biomass is the dry weight of
living organic matter in an
area
- Can include above, or
belowground or both - Good reflection of the
productivity of an ecosystem
prodactivity vs biomass
productivity how much energy stored
vs
biomass wich represents the physical mesurment
Monitoring the Biosphere Historically
Biosphere
Field based estimates
- Estimating vegetation cover, vegetation width & height
- Gives us an estimate of biomass
