misc
1. Hypothesis
A proposed explanation for a phenomenon.
Example: If I add fertilizer to my plants, then they will grow taller.
2. Null Hypothesis
A statement that there is no relationship between two variables.
Example: If I add fertilizer to my plants, then there will be no significant statistical difference, it is random chance.
3. Control group
A group in an experiment that does not receive the treatment.
Example: In a plant growth experiment, the control group would be plants without fertilizer.
4. Responding variable
The variable that is measured in an experiment.
Example: Plant height in a fertilizer experiment.
5. Manipulative variable
The variable that is changed in an experiment.
Example: Amount of fertilizer in a plant growth experiment.
6. Ecosystem
A biological community of interacting organisms and their physical environment.
Example: A forest, a pond, a coral reef.
7. Biotic
Living organisms and their products.
Example: Plants, animals, bacteria.
8. Abiotic
Non-living physical and chemical components of an ecosystem.
Example: Water, air, soil, sunlight.
9. Biodiversity
The variety of life in the world or in a particular habitat.
Example: A rainforest has high biodiversity due to its many different plant and animal species.
10. Biosphere
The part of the Earth and its atmosphere that can support life.
Example: Includes all ecosystems on Earth.
11. Ecological footprint
A measure of human demand on the Earth's ecosystems.
Example: The average ecological footprint of a person in the United States is much larger than that of someone in India.
12. Sustainable development
Development that meets the needs of the present without compromising the ability of future generations to meet their own needs.
Example: Using renewable energy sources instead of fossil fuels.
13. Biophilia hypothesis
The innate human tendency to seek connections with nature.
Example: People often feel happier and more relaxed in green spaces.
14. Gaia Hypothesis
The Earth is a self-regulating organism.
Example: The Earth's climate system adjusts to maintain a habitable temperature.
15. Background Extinction rate (BER)
The normal rate of extinction of species.
Example: The BER is estimated to be about one species per million species per year.
16. Anthropogenic
Human-induced changes to the environment.
Example: Climate change, deforestation, pollution.
17. Positive feedback loop
A process where a small change in one variable leads to larger changes in the same direction.
Example: Global warming: Increased temperatures lead to melting ice, which reduces reflectivity and increases absorption of heat, leading to further temperature increases.
18. Negative feedback loop
A process where a small change in one variable leads to changes in the opposite direction, returning the system to its original state.
Example: Predator-prey relationships: An increase in prey population leads to an increase in predator population, which eventually reduces the prey population.
19. Trophic levels
The position an organism occupies in a food chain.
Example: Producers (plants), primary consumers (herbivores), secondary consumers (carnivores).
20. Food chain and food web
A linear sequence of organisms through which energy and nutrients flow (food chain); a complex network of interconnected food chains (food web).
Example: Grass -> Rabbit -> Fox (food chain); a variety of plants and animals interacting in an ecosystem (food web).
21. 10% rule
Only about 10% of the energy in one trophic level is transferred to the next.
Example: If a plant has 1000 kcal of energy, only about 100 kcal will be transferred to a herbivore that eats it.
22. Detritivore
An organism that feeds on dead organic matter.
Example: Earthworms, millipedes, and vultures.
23. Biomass
The total mass of organisms in a given area.
Example: The biomass of a forest includes the mass of all trees, plants, animals, and microorganisms.
24. GPP
Gross Primary Productivity: The total amount of solar energy captured by producers through photosynthesis.
Example: The GPP of a forest is the total amount of energy captured by plants.
25. NPP
Net Primary Productivity: The amount of energy available to consumers after producers use some for respiration.
Example: The NPP of a forest is the GPP minus the energy used by plants for respiration.
26. Intermediate disturbance hypothesis
Ecosystems experiencing intermediate levels of disturbance have the highest biodiversity.
Example: A forest with occasional fires may have more plant and animal diversity than a forest with no fires or frequent, severe fires.
27. Cellular respiration
The process by which organisms convert glucose into energy.
Example: Humans and plants undergo cellular respiration to produce ATP.
28. Scavenger
An animal that feeds on dead animals.
Example: Vultures, hyenas, and raccoons.
29. Ecological efficiency
The percentage of energy transferred from one trophic level to the next.
Example: Typically, only about 10% of energy is transferred to the next trophic level.
30. Micronutrient
Nutrients needed in small amounts for organisms to survive.
Example: Iron, zinc, and copper.
31. Macronutrient
Nutrients needed in large amounts for organisms to survive.
Example: Nitrogen, phosphorus, and potassium.
32. Easter Island ecological disaster
A classic example of human-induced environmental degradation leading to societal collapse.
Example: Deforestation, soil erosion, and resource depletion on Easter Island led to the decline of its civilization.
33. Bioaccumulation
The gradual build-up of toxic substances in living organisms over time.
Example: The accumulation of DDT in the tissues of fish.
34. Biomagnification
The increasing concentration of a toxic substance in organisms at higher trophic levels.
Example: The concentration of mercury in fish-eating birds.
35. Speciation
The formation of new species.
Example: The Galapagos finches developed different beak shapes through speciation.
36. Allopatric speciation
The formation of new species due to geographic isolation.
Example: A population of squirrels separated by a river may eventually evolve into two different species.
37. Sympatric speciation
The formation of new species without geographic isolation.
Example: The apple maggot fly evolving different preferences for apple and hawthorn fruits.
38. Nitrogen fixation
The process of converting atmospheric nitrogen gas into a usable form for plants.
Example: Bacteria in the soil convert nitrogen gas into ammonia.
39. Carbon fixation
The process of converting carbon dioxide into organic compounds.
Example: Plants use photosynthesis to convert carbon dioxide into glucose.
40. Habitat fragmentation
The division of large, continuous habitats into smaller, isolated patches.
Example: Deforestation breaking up a forest into smaller, isolated areas.
41. Edge effects
Changes in population or community structures that occur at the boundary of two or more habitats.
Example: Increased sunlight and wind at forest edges can create different microclimates, leading to different plant and animal species.
42. Resource partitioning
Different species using the same resource in different ways to avoid competition.
Example: Different bird species feeding on insects in different parts of a tree.
43. Carrion
Dead animal flesh.
Example: Vultures consume carrion.
44. Keystone species
A species that has a disproportionately large impact on its environment relative to its abundance.
Example: Sea otters help to maintain kelp forests by controlling sea urchin populations.
45. Riparian zone
The area of land along a river or stream that is influenced by water.
Example: Wetlands, forests, or grasslands that border a river.
46. Biological Oxygen Demand (BOD)
A measure of the amount of oxygen consumed by microorganisms in decomposing organic matter in water.
Example: High BOD levels indicate polluted water with high levels of organic waste.
47. Dissolved Oxygen (DO)
The amount of oxygen dissolved in water, essential for aquatic life.
Example: High DO levels are necessary for fish and other aquatic organisms to survive.
48. Eutrophication
Excessive nutrient enrichment in a water body leading to algal blooms and oxygen depletion.
Example: Nutrient runoff from fertilizers can cause eutrophication in lakes.
49. Phytoremediation
The use of plants to clean up contaminated soil or water.
Example: Certain plants can absorb heavy metals from contaminated soil.
50. Species Diversity
The variety of species in a given area.
Example: A rainforest has high species diversity compared to a desert.