Take Away Messages & Key Points

Hi All,
Here are key points and Take Away messages from each lecture that will be covered on the Midterm.
Hope it's helpful!

Take Away Messages, Key Points, & Learning Objectives

Lecture 1

• Evidence suggests we are now in the “full world” situation. But many of our actions and decision making frameworks were formed during the “empty world” situation.
• No organism lives disconnected from its abiotic environment and from other organisms
• The ecosystem concept is a marriage of population-community ecology with a systems view of rates and quantities that aggregates over species … also links biotic and abiotic processes together

Lecture 2

• All animal phyla evolved in marine environments and most animal phyla remain in marine environments – terrestrial and freshwater animal groups are a very small subset of phyletic diversity (though a large proportion of species diversity)

• On a Global Level, diversity reflects the relative rates of speciation and extinction – an input/output model!

Lecture 3
• 1st law of thermodynamics: energy is neither created nor destroyed, only transformed
• KEY POINT: energy flows from low to high entropy in a system
• KEY POINT: atmosphere is heated from below (lw, not sw)
• KEY POINT: The flow of energy drives all ecological processes.
• KEY POINT: living things store energy in reduced carbon compounds; in metabolism they become oxidized

• Solar radiation is called sw b/c it peaks there; radiation emitted by Earth is called lw b/c it peaks there
• Every organism produces energy waste through respiration; this causes the trophic pyramid
• Living things store energy as reduced C, then slowly oxidize it through a highly efficient series of steps, to CO2
• Earth surface converts sunlight to sensible heat latent heat and lw radiation, which heats the atmosphere from below
• The Earth is a huge engine for moving heat from the tropics to the extratropical latitudes

Lecture 4

• Different types of vegetation are strongly adapted to different regimes of sunlight, T, and moisture. Their global distribution reflects this adaptation.
• Compensation points regulate where Ps balances respiration in both terrestrial and aquatic systems (based on light extinction), limiting NPP

Learning objectives:
• Greater insight into primary production: what it is, what controls it
• Terrestrial and aquatic ecosystems
• Learn the basics about photosynthesis: what it is, what controls it
• Understand what limits primary production
• Understand some fundamental principles of how types of vegetation are adapted to light, temperature, moisture, and soils

Lecture 5

• Decomposition itself creates recalcitrant molecules in soil that can persist a long time

Learning Objectives:
• Understand relationships among GPP, NPP, NEP, NEE, NBP, and NECB
• Understand what is measured by flux towers
• Learn basic controls on C storage in terrestrial ecosystems, basics of C accounting in ecosystems
• Understand the roles of disturbance and succession in terrestrial ecosystems

Lecture 6

• C in fossil fuels and many carbonate rocks used to be in the atmosphere and oceans
• Cenozoic has seen a trend in cooling, sea level fall, decline in forests, also decline in CO2

Key themes
• Past CO2 and global temperatures show close correlation over the most recent 100,000 to 400,000 year time scale
• Global temperatures, glaciations, and sea level result from a complex interplay of factors, including:
• Moving positions of continents
• Milankovitch cycles in the earth’s orbit
• Atmospheric CO2 and other greenhouse gases
• Global and continental temperatures probably change as a result of feedbacks
• Feedbacks that may have historically involved atmospheric CO2

Lecture 7

Key Themes:
• Global circulation and continental effects
• Soils and soil development
• Global scale vegetation biomes
• Regional, landscape, and local scale patterns

Lecture 8

• Acids and bases are compounds that _do_ affect pH of water, by donating or consuming H+
• A strong acid will donate H+ even when pH is low; a weak acid does not. H2CO3 is a weak acid.
• Speciation of H2CO3 is controlled by pH, but also itself helps regulate pH.
• pH of natural water is regulated by chemistry of numerous simultaneousdissoc. & re-association reactions
• Ocean acidification will cause species losses. Earth has seen this before. But current rate of change is much more rapid.

Learning Objectives:
• Biogeochemistry
• Water as a universal solvent and acid-base chemistry
• Carbonate complex in natural waters
• Ocean acidification
• N and S emissions and acid rain
• Mineral weathering and acid-neutralizing capacity
• Watershed input-output budgets

Lecture 9

Take Home Messages:
• Any nutrient is limiting to production up to a point. Then when it is plentiful, something else becomes limiting.

Lecture 10

Key Points
• Nitrification is aerobic and produces NO3- as an end product
• Denitrification is anaerobic and uses NO3- as an input, and consumes it, producing gaseous forms of N as an output

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