Organism - individual animal or bacteria or plant. Is alive. 

Population - group of organisms of the same species living together 

Species - organisms of the same type with a set of common characteristics that can interbreed to create fertile offspring (has the caveat of what if the organism is just infertile? Does that make infertile humans not part of the species? This is a general definition)

Community - group of populations of different species living in the same area

Ecosystem - community PLUS the abiotic factors (rocks, water, temperature, sunlight, etc.). All previous ecological organization are JUST biotic factors (living)

Biome - type of environment with specific traits (tundra, taiga, grasslands, etc.). Usually have different abiotic and biotic factors. 

Biosphere - every single ecosystem on the planet earth. 

Chain - single line of organisms connected by arrows (tree → bird → eagle → me)

Web - multiple chains connected together to show how energy is transferred within an ecosystem. Often a lot more complicated than a single chain. 

Arrow - the indication of what eats what and how energy is transferred

Trophic level - the tier of the pyramid/chain that an organism occupies—indicates who do they eat, and who eats them? organisms can occupy multiple trophic levels (this is accurate) 

Ecological Pyramids - another way to show the flow of energy/biomass/number within an ecosystem, with producers at the bottom of the pyramid and the apex predators at the top. Energy moves upward. 

1st Law of Thermodynamics - energy can be neither created nor destroyed, only transformed/transferred

2nd Law of Thermodynamics- energy is not transferred efficiently, some of it is inevitably lost along the way (hence the 10% rule) 

Benefits and drawbacks of ecological pyramids - 

BENEFITS - show the flow of energy, show the 10% rule/size of each population by the diminishing size of the blocks, generally easier to read lol?? 

DRAWBACKS - ecosystems are much more complicated, organisms often eat more than one thing. Pyramids do not show that. Doesn’t allow for multiple animals to be on the same level.

Benefits and drawbacks of food webs

BENEFITS - show the complexity within an ecosystem

DRAWBACKS - do not show the 10% rule, nor do they quantify how many of each organism there are ? Don’t show trophic levels. 

Producer - First trophic level. produce their own energy, usually through photosynthesis. (trees, flowers, plants, sometimes bacteria)

Primary consumer- first consumer, second trophic level. Eats the producers (herbivores)

Secondary consumer - second consumer, third trophic level. Eats the primary consumers (carnivores)

Tertiary consumer- third consumer, fourth trophic level. Eats the secondary consumers. 

Apex predator- general term for the predator at the top of the food chain at fifth trophic level. General the fewest in number (the number of organisms per trophic level decreases the higher you go up because of the 10% rule)

10% rule - 2nd law of thermodynamics states that energy is not transferred in its entirety—it is always lost. The 10% rule follows this. From trophic level to trophic level, only about 10% of energy actually makes it to the next trophic level because of respiration and other factors that require energy. This is why the top of the pyramid has so few organisms because there’s only about like 1% or 0.1% of the original energy, so it can only support a few (if any at all)

Pyramid of numbers (and inversion)

Shows the abundance of a species (how many of each organisms are there) - the larger, the more populous.

Ex: lots of trees, supporting a few primary consumers, supporting even fewer secondary consumers → normal pyramid looking shape

Often inverted: one tree can support a lot of birds, who may support even more somethings

Pyramid of biomass

BIOMASS - the mass of a bio. JK just the mass within all living things in a given area 

Pyramid of biomass shows how much mass is within each organism. 

Rarely inverted - even if there’s a lot of an organism, they are usually lighter so the biomass pyramid factors that in. 

Example of inversion: ocean, where there are a lot of secondary consumers and the primary consumers are veeeery small

Pyramid of energy

The pyramid we were thinking about earlier with the energy that shows the flow of energy throughout an ecosystem. NEVER inverted, because that would violate the 1st law of thermodynamics. 

Bioaccumulation (+ examples of toxins)

When a toxin builds up within the body of an organism that is eating it. Occurs at a singular trophic level (think of a cow eating grass with DDT or something)

Biomagnification

When the toxin grows stronger in terms of ratio across trophic levels. 

Cow eats grass, then wolf eats cow, the ratio of toxin to non toxin decreases as you move up a trophic level?? 

Occurs as a result of the 2nd law of thermodynamics as it grows more concentrated and doesn’t get degraded. Shifts from 1% to maybe 10% to more.  

Productivity - the amount of biomass/energy transferred between trophic levels within a period of time 

Rate at which energy is added to bodies of a group of organisms in the form of biomass

Gross productivity - total biomass transferred within a period of time within an entire ecosystem (not usually used)

TOTAL GAIN IN ENERGY

Gross primary productivity - productivity (biomass transferred within a period of time) of all the producer — basically, how much RATE the producer is able to photosynthesize

Factors that affect GPP- sunlight, water, temperature, soil quality/nutrients, competition of other plants, etc. another one is the herbivores and quantity of CO2. 

Net productivity- GP - respiration = the amount of usable energy as some of it is lost to cellular respiration

Net primary productivity- GPP - R = NPP. amount of energy stored 

Ways to measure productivity- 

O2 - how much oxygen or dissolve oxygen (DO) was produced within a contained environment or how much oxygen was used from cell respiration

CO2 - how much CO2 was used up within a contained environment to measure GPP or how much CO2 was produced from cell respiration

Harvest method (ONLY FOR PRODUCERS) - allow producer to grow from known beginning height → wait → cut back to the original height (KILLS the plant) 

Collecting cuttings, dry, then measure. NPP is the dry biomass. 

Secondary productivity - the amount of biomass added to an organism per period of time (of consumers)   

GSP, NSP (how to calculate) - 

NPP (food eaten) - poop = GSP (they lose some at that stage as well) 

GSP - R = NSP 

Bottle Method - place one bottle of water with organisms within it in the light, the other in the dark. One will be able to photosynthesize and respire, the other will only be able to respirate

GPP = Light - Dark = (photosynthesis + respiration) - respiration = photosynthesis

R = Initial - Dark = how much was at the beginning - how much was lost = the difference

GPP - R = NPP.