Lecture 15 + 16 Flashcards
True or false: Divestment is the action or process of selling off subsidiary business interests or investments.
True
True or false: The Cornell board of trustees considers divesting its endowment assets from a company only when the company’s actions or inactions are morally reprehensible.
True
Which of the following types of institutions can engage in divestment? (you may select one or more answers)
- universities and colleges
- religious institutions
- insurance companies
- city pension funds
- nations
- universities and colleges
- religious institutions
- insurance companies
- city pension funds
- nations
According to the speaker’s “7 or 8 changes” portion of the talk, which 3 of the following statements are false:
1. The climate crisis is deepening over time.
2. Solar and wind power still remain more expensive that power generated by fossil fuels.
3. Developing nations do not use solar power.
4. Institutions that divest can do well financially
5. Fossil fuel companies had information concerning global warming 30 years ago.
6. Mitigating climate change will require work
7. Divestment has little support
8. Academic studies demonstrate that the divestment campaign has been successful
- Solar and wind power still remain more expensive that power generated by fossil fuels.
- Developing nations do not use solar power.
- Divestment has little support
True or false: According to the speaker we are certain to win “the climate change battle”.
False. The speaker was uncertain.
True or false: Because of the dangers associated with nuclear power the speaker prefers coal power to nuclear.
False. He considered nuclear power as a risk, while a coal power plant will certainly do damage.
What refers to the mass of organisms per unit area?
Biomass
Which of the following is an accurate definition of primary productivity?
- The rate at which a standing crop is produced or the volume at which plants photosynthesize.
- The rate at which biomass is produced per unit area or volume through photosynthesis
- The formation of essential plant structures
- The rate of formation of essential plant structures over a photosynthetic period.
- The rate at which a standing crop is produced or the volume at which plants photosynthesize.
What refers to the rate of production of biomass by heterotrophs?
Secondary productivity
Which biome has the greatest overall NPP?
Tropical rain forest
Populations
Groups of organisms of the same species in a defined area
Communities
All of the populations (different species) in a defined area
Ecosystems
The community of organisms interacting with the physical-chemical environment
- entire lakes or ponds, entire bogs or marshes, entire forests or defined parts of forest, entire pieces of oceans -> considered as a functioning unit
- boundaries are defined
Biosphere
All life interacting with the physical environment at the scale of the entire planet
Why study ecosystems?
- In general, need to study next lowest scale of organization to gain understanding of underlaying mechanisms at the scale of interest.
- Ecosystems are the appropriate scale for understanding functioning for many purposes of environmental management, including response to global change.
Why focus on primary production? All organisms need energy.
Second law of thermodynamics: increase in entropy (decrease in order) over time in the universe, and in any system…
…but only if there are no external inputs of energy to the system
Organisms and ecosystems are highly ordered systems, maintaining order through continual energy inputs.
Primary production is the source of most of that energy.
Primary production
The total amount of plant (or algal or cyanobacterial) material produced or energy captured per surface area per time. This is photosynthesis.
- this is a rate
Rate of primary production
Can be expressed in units of energy per area per time (joules m-2 yr-1), power per area (watts m-2 ), mass per area per time (g dry weight m-2 yr-1), or organic carbon per area per time (g C m-2 yr-1).
Different areas and times can be considered: square metres or square km, and hours or days or years.
The text generally uses g C m-2 yr-1
Gross primary production (GPP)
Total amount of photosynthesis per surface area per time
Total rate of CO2 fixed into organic matter per time
Represents total ecosystem photosynthesis
Net primary production
GPP minus the respiration of plants or algae carrying out photosynthesis per surface area per time
- represents the total amount of organic matter available for consumption by higher trophic levels, or for harvesting by humans
Autotrophic respiration (Ra)
Rate of respiration (energy consumption) by primary producers for their own maintenance and energy needs
How much of the energy of GPP do you think plants respire for their own metabolic needs?
50% or so on average
Across a wide range of terrestrial ecosystems, NPP = approximately 50% of GPP
That is, half of total photosynthesis is being used by the plants to meet their metabolic needs (for nutrient uptake, growth, defence against herbivory, etc.)
- terrestrial ecologists often focus on the factors controlling NPP
-> not true in aquatic ecosystems
What regulates NPP in terrestrial ecosystems?
Average pattern of NPP in terrestrial ecosystems is controlled by water availability
- highest in wetlands, tropical forests, temperate forests
- lowest in dune, rock, ice, desert, tundra