• Sustainability: ability of a system to survive and function over time.

• Sustainable yield: the highest rate at which a potentially renewable resource can be used indefinitely without reducing its availability.

• Potentially renewable source: Can be replenished fairly rapidly. Must be harvested below the sustainable yield limit.

• Open access resource: resources which are owned by no one but are available to all users free of charge.

• Nonrenewable resource: Resource that can not be replenished at a reasonable rate.

• Gross domestic product (GDP): All goods and services produced within a country during a year.

• Per capita GDP: The GDP divided by the total population (per person value).

• Developing nations: countries that have low or moderate industrialization 

• Developed nations: countries  that have high industrialization

• Reuse: is the practice of using an item more than once before it is disposed of.

• Recycling: processing a resource into a new product

• Closed-loop recycling:  Products that can only be recycled into another type product (lesser quality).

• open-loop recycling: Can be recycled into the same product

• Point source pollution: Pollutants from a single, identifiable source, such as a power plant.

• Nonpoint source pollution: Pollutants from many dispersed sources, such as pesticide runoff or automobile exhaust.

• Biodegradable: Broken down by chemical, physical, or biological processes.

• Nondegradable: Can not be broken down.

• Ecological footprint: a measure of how much an individual consumes, expressed in an area of land

• External costs: Cost not reflected in the price.

• Independent variable (manipulated): a variable that is not dependent on other variables

• Dependent variable (responding): a variable that is dependent on other factors

• Controlled variable (constants): any variable that's held constant in a research study

• Validity (accuracy): How close a measured value is to the actual or true value

• Reliability (precision): how close the repeated measurements of a sample to one or another

• Positive Feedback Loop: an input causes the system to change in the same direction, escalating the outcome.

• Negative Feedback loop: an input causes the system to change in the opposite direction from which it is moving.

• Abiotic: a living (or once living) component of an ecosystem

• Biotic: a nonliving component of an ecosystem

• Limiting factors: those that are responsible for regulating the population in proportion to its density such as competition, predation, and diseases

• Limiting factor principle: Too much or too little of any abiotic factor can limit or prevent growth of a population, even if all other factors are at or near the optimal range of tolerance

• Trophic level: a step in a food chain

• autotroph/producer: First Trophic Level; producers (plants)

• heterotroph/consumer: Second Trophic level; Primary consumers (herbivores); incapable of photosynthesis and must obtain its energy by consuming other organisms 

• Herbivore: a consumer that eats producers (aka primary consumers)

• Carnivore: a consumer that eats other consumers

• Decomposer: secrete enzymes to break down dead organisms. Recycle nutrients into the surrounding area.

• Detrivior (detritus feeders): consume dead organisms.

• Biomass: The total mass of all living matter in a specific area

• Ecological efficiency: The percentage of usable energy transferred from one trophic level to the next.

• Rule of 10%: 10% is generally considered to be the ecological efficiency of food chains.

• Gross Primary productivity (GPP): the rate at which producers convert solar energy (for almost all producers) into chemical energy.

• Net primary productivity (NPP): the amount of chemical energy available after the energy requirements of the producer have been subtracted.

• Oxygen-demanding wastes: Organic wastes that can be decomposed by aerobic bacteria; sewage, animal waste.

• Biological oxygen demand (BOD): the dissolved oxygen needed by aerobic decomposers to break down the organic materials in a certain volume over a 5–day incubation period at 20° C.

• Equation for photosynthesis: 6CO2 + 6H2O → C6H12O6 + 6O2. 

• Equation for cellular respiration: C6H12O6 + 6O2 → 6CO2 + 6H2O (glucose + oxygen -> carbon dioxide + water)

• Eutrophication: excessive nutrients from fertilizers, sewage, runoff from poultry and hog farms

• Thermal pollution: power plants and factors using water to cool equipment, runoff from roads (warmed), shallow and stagnant water that doesn’t mix

• Bioaccumulation: The percentage of usable energy transferred from one trophic level to the next.

• Biomagnification: an increase in the concentration of a substance in organisms higher up in the food chain. This occurs because each step in the food chain must consume a greater amount then the previous level.
  

• Definition: A situation where individuals, acting in their own self-interest, deplete a shared resource that is not owned by anyone.

• Examples: Overfishing, deforestation, groundwater depletion, air pollution.

• Strategies to reduce overexploitation:

  • Regulation: Government policies to limit resource use and establish sustainable practices.

  • Privatization: Assigning ownership of resources to individuals or groups to incentivize responsible management.

  • Communal ownership: Creating shared governance structures to ensure equitable resource distribution and sustainable use.

  • Education and awareness: Promoting understanding of the consequences of overexploitation and encouraging responsible behavior.

Per Capita Ecological Footprint:

• The average American has a significantly higher per capita ecological footprint compared to citizens of most European nations, China, and India. This is primarily due to higher consumption patterns, resource use, and carbon emissions.

Importance of a Single Independent Variable in Experiments:

• Isolation of effects: Manipulating only one variable allows scientists to determine its specific impact on the dependent variable, eliminating confounding factors.

• Clarity of results: A single independent variable makes it easier to draw conclusions about cause-and-effect relationships.

• Replicability: Experiments with a single independent variable are more likely to be replicated by other researchers, strengthening the validity of the findings.

Purpose of a Control Group:

• Comparison: A control group provides a baseline for comparison, allowing scientists to isolate the effects of the independent variable.

• Elimination of confounding factors: By keeping all variables constant except for the independent variable, the control group helps to rule out other potential explanations for observed changes.

• Validity of results: A control group enhances the credibility of experimental findings by demonstrating that the observed changes are indeed due to the manipulation of the independent variable.

Writing Scientific Questions:

• Identify the independent variable (the factor being manipulated) and the dependent variable (the factor being measured).

• Frame the question in a way that clearly indicates the relationship between the two variables.

Hypothesis:

• A testable statement that predicts a relationship between the independent and dependent variables.

• Includes a clear prediction about the expected change in the dependent variable.

Energy Flow and Nutrient Cycling:

• Energy flow: Energy flows through food chains in a one-way direction, from producers (like plants) to consumers (like herbivores and carnivores). Energy is lost at each trophic level due to metabolic processes (respiration) and heat dissipation, resulting in a pyramid-shaped energy structure.

• Nutrient cycling: Nutrients (like carbon, nitrogen, phosphorus) are recycled between organisms and the environment in a cyclical manner. These cycles involve various reservoirs (like the atmosphere, soil, water) and processes (like decomposition, photosynthesis, respiration).

Food Chains as Energy Pyramids:

• Second Law of Thermodynamics: This law states that energy tends to disperse into less useful forms (like heat) over time. In food chains, energy is lost at each trophic level due to respiration and other processes, leading to a decrease in available energy for higher levels. This results in a pyramid-shaped structure, with fewer organisms at higher trophic levels.

Ecological Efficiency:

• The typical ecological efficiency for a food chain is around 10%, meaning only 10% of the energy from one trophic level is transferred to the next.

Energy Availability Through Trophic Levels:

• Producer level: 100%

• Primary consumer level: 10%

• Secondary consumer level: 1%

• Tertiary consumer level: 0.1%

Ecosystems with Highest NPP:

• Tropical rainforests

• Estuaries

• Coral reefs

Factors Affecting NPP:

• Temperature

• Precipitation

• Nutrient availability

• Light availability

• Soil conditions

Open Ocean NPP:

• The open ocean has the highest total NPP due to its vast size, but it has a lower NPP per area rate compared to other ecosystems. This is because the nutrient-poor surface waters limit productivity.

Measuring NPP:

• NPP = GPP - R

• GPP: Total amount of carbon consumed by plants (measured using light-dark bottles or carbon dioxide uptake)

• Respiration: Measured by tracking the release of carbon dioxide by plants

Biogeochemical Cycles:

• Carbon cycle: Involves the exchange of carbon between the atmosphere, oceans, land, and organisms through processes like photosynthesis, respiration, and decomposition.

• Nitrogen cycle: Involves the conversion of nitrogen between various forms (like atmospheric nitrogen, ammonia, nitrate) through processes like nitrogen fixation, denitrification, and ammonification.

• Phosphorus cycle: Primarily involves the movement of phosphorus between the land, water, and organisms. It is a slower-cycling nutrient compared to nitrogen and carbon.

• Hydrologic cycle: The continuous movement of water between the Earth's surface, atmosphere, and underground.

Nitrogen and Phosphorus as Limiting Factors:

• Nitrogen and phosphorus are often limiting factors in plant growth because they are essential nutrients that are often in short supply in ecosystems.

Carbon Reservoirs:

• Fast cycling: Atmosphere, biosphere, oceans

• Slow cycling: Fossil fuels, sediments

Photosynthesis and Cellular Respiration:

• Photosynthesis: 6CO2 + 6H2O + light energy -> C6H12O6 + 6O2

• Cellular respiration: C6H12O6 + 6O2 -> 6CO2 + 6H2O + energy

Eutrophic Lake:

• Excess nutrients (like nitrogen and phosphorus) lead to algal blooms, which can deplete oxygen levels and harm aquatic life.

Temperature and Dissolved Oxygen:

• As temperature increases, the solubility of oxygen in water decreases. This can lead to oxygen depletion in warm waters, affecting aquatic organisms.

Causes of Thermal Pollution:

• Industrial discharges: Hot water from factories and power plants can raise the temperature of nearby water bodies.

• Runoff from urban areas: Paved surfaces can absorb heat and release it into stormwater runoff, affecting water quality.

Quantitative Questions and Dimensional Analysis:

• Use conversion factors to convert between units.

• Set up dimensional analysis problems to ensure correct units cancel out.

Scientific Notation:

• Express numbers as a product of a number between 1 and 10 and a power of 10.

• Multiply and divide numbers in scientific notation by adding or subtracting the exponents, respectively.