Last Lecture

Currie’s Summary of his lectures

1. Core themes and systems approach
• sustainability and full world concept of human inmpacts
• introduction to ecology as a science and ecosystems as life-support systems
• introduction to the laboratory and systems thinking
• introduction of biotic hierarchy (key structure and concepts: heat exchance, photosynthesis, nutrient cycling, energy flux, carbon cycle, global systems, landscapes and biomes, population dynamics)

2. Energy, Life and Transformations
• solar radiation, thermal radiation, energy, heat
• should be able to explain how, in a trophic level or organism, how energy comes, how its assimilates, how respiration works, and how energy becomes available for next trophic level.
• should be able to talk about ecological concepts on trophic level (consumption and predation)
• heat exchange and energy budget of leaf and plants. Long wave, short wave, thermal radiation

3. Plant physiology, Energetics, and Water relations
• Photosynthesis: C3, C4 and CAM (C4 and CAM separate light and dark reactions)
• Finepoint: photorespiration is not really respiration (CAM and C4 allow you to close the stomates to reduce water loss)
• You should know the difference between the different types of photosynthesis, difference between light and dark reactions,

4. Terrestrial production, decomposition, carbon cycle, NPP, GPP
• “global terrestrial carbon uptake and release” is the unifying diagram from this lecture. You should be able to describe each of these processes and how they relate to each other.

• NEP is kind of a old term. Ecologists are trying to replace that term with the new term: NECB (net ecosystem carbon balance).
• Eddy-flux towers. Parcels of air moving eddies at different scales-measure CO2 and water vapor—can calculate C02 exchange.

5. Climate, Glaciation, and Stability
• global temps, c02 and sea level at different times
• understand feedback and stability in different ages
• milankovitch cycles

6. Vegetation Biomes
• global atmospheric circulation
• regional and continental scale effects
• unifying theme: annual seasonal climate controls vegetation and soil development (including interaction between soil and vegetation)
• Soil: age, fertility, water holding capacity all determine type of vegetation
• walter and whittacker diagrams

7. Water
• Co2 dissolves in water and forms H2C03 (carbonic acid) which then disassociates.
• What dominates depends on the ph (carbonic acid, bicarbonate, carbonate)
• Ocean is acidifying—what does that matter: biogenic calcite is harder to form. Organisms can’t build shells because of acidity
8. Nitrogen Cascade
• Humane activities introduce reactive N into the atmosphere. (human activities convert non-active N into reactive N).
• Food production, energy production, and people
• Nitrification—— ammonium to nitrate
• Denitrification—why is it important? Nitrate is more mobile, ammonium tends to stay put.
9. Nutrient Cycling in terrestial ecosystems
• nitrogen satuation
• movement of nitrogen—understanding “Aber and Melillo 1991 Terrestial Ecosystems” nitrogen cycling diagram is important

10. Land Use/Land Cover change
• different speciies perceive the environment at different scales
• historical land use has changed carbon production.
• Tropics are still being deforested for food production and biofuel production

11. Agriculture
• Neolithic revolution
• Green revolution
• Genetic revolution
• Big question: Does humane population growth drive agricultural growth or vice versa?

12. Global carbon cycling
• Sources of sinks
• Dynamic systems
• Carbon mitigation
• Stabilization wedges
• Key concepts: carbon pool are really large, before industrial revolution pools were balanced, since then
• 8 gigatons of increased emissions (2 terrestial sinks, 2 in the ocean…)
• missing sink concept: unidentified sinks. We know its there because there is a residual sink/difference.
NOTE: Next more important slides are located on the Ctools site

Last Lecture by David Allan
Ecology: Science of Context and Interaction


1. brief history planet earth & the origins of Life
• number of advances (often crisis inducing): photosynthesis, aerobic respiration, cell formation
• link the understanding of the formation of species through geographic formation(?)

2. Evolution by natural selection
• A collection of ideas: mechanism of natural selection, notion of life diversification, mechanism for evolutionary change (most significant), other scholars knew it happened by Darwin articulated natural selection as mechanism
• Q. If natural selection is so strong, and certain genotypes are so good, wouldn’t natural selection eliminate genetic variation? There needs to keep variation in place (without which you cannot have evolution): environmental variance, shifts in directional selection, trade-offs, inclusive fitness (altruistic behavior—think meercats)

3. Population Growth

• Growth without limits
• Carrying capacity and s-shaped growth
• How populations regulated
• Time lags and population oscillilations

4. Population dynamics and age structure
• Survivorship and maternity functions (lx and mc)
• Estimating future populations with life tables and matrices
• Population viability analysis (being able to predict the likely success or extinction of a particular species)
• Populations have spatial structure (populations aren’t uniform, patchy habitats, etc. )
• Source-sink (birth rates aren’t higher than death rates—survive only with immigration from other populations) and metapopulation dynamics (corridors, etc)

5. Species Interaction
• Types of interactions within species networks
• Mutualism and commensalisms
• Competitions and the concept of the niche
• How do you explain coexistence?

6. Consumer-Resource Interactions
• How predators affect prey populations and vice-versa
• Predation is a powerful agent of natural selection
• What stabilizes predator-prey interactions and prevents their collapse
• How predation can result in complex interactions in natural communities (super consumers can cause havoc)

7. Community Structure
• Interaction within assemblages of co-occurring species
• Food web analysis (categorize by trophic levels, functional

8. Lake Ecosystems
• Primary production, nutrients, and eutrophication (phosphorous—caused eutrophication.) hourglass lake experiment
• In marine systems its nitrogen that causes eutrophication (Mississippi delta dead zone)

9. River Ecosystems
• River continuum concept (dead leaf material growth along with microbes that feed on them—then algae growth—then small organic particles)
• Different parts of the river have different consumers
• Global water—water cycle (should have good understanding)
• Different pathways that water follows

10. Global Diversity
• # of species are determined by the size of patch surveyed.

11. The Biodiversity Crisis

What causes species threats
• Overexploitation
• Invasive species
• Habitat loss
• (above are three biggest ones)
• pollution
• domino effects

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