| A | B |
|---|
| Ecosystem | particular location on Earth distinguished by its particular mix of interacting biotic and abiotic components |
| Producers / autotrophs | plants, algae or other organisms that use the sun's energy to produce usable forms of energy |
| photosynthesis | producers use solar energy to convert CO2 and H2O into glucose (C6H12O6), a form of potenial energy that can be used by many organisms |
| cellular respiration | opposite of photosynthesis; cells convert glucose and O2 into energy, CO2, and H2O |
| consumers/ heterotrophs | incapable of photosynthesis so consume other organisms to obtain energy |
| primary consumers | consumer producers; herbivores |
| secondary consumers | heterotrophs that obtain energy by eating other consumers; carnivores |
| tertiary consumers | carnivores that eat secondary consumers |
| trophic levels | successive levels of organisms consuming one another; only ~ 10% of energy from one level is recovered by the next due to loss from cellular respiration, heat, and not all are eaten |
| food chain | sequence of consumption from producers through tertiary consumers |
| food web | shows interconnectedness of food chains in an ecosyem |
| Omnivores | eat plants and animals; can be on multiple trophich levels |
| Scavengers | carnivores that consume already dead animals; ex: vultures |
| Detrivores | organisms that break down dead tissues and waste products (detritus) into smaller particles; ex: dung beetles |
| Decomposers | processes detritus so the nutrients can be recycled back into the ecosystem; ex: bacteria, fungi |
| Gross primary productivity (GPP) | the total amount of solar energy that the producers in an ecosystem capture via photosynthesis over a given amount of time (gross means total) |
| net primary productivity (NPP) | NPP=GPP - respiration by producers; establishes the rate at which biomass is produced over a given amount of time |
| biomass | total mass of all living matter in a specific area |
| standing crop | amount of biomass present in an ecosystem at a particular time |
| ecological efficiency | proportion of consumed energy that can be passed from one trophic level to another; 5-20% |
| trophic pyramid | represents the biomass among trophic levels; also indicates amount of energy available |
| biosphere | combination of all ecosystems on Earth; where life resides; 20 km (12 mile) shell around Earth from deepest parts of the ocean to the highest mountain peak |
| geochemical cycles | the movements of matter (pools) within and between ecosystems involve biological, geological, and chemical processes (flows) |
| hydrological cycle | movement of H2O through the biosphere; between animals, plants, water bodies, soils, atmosphere; water carries dissolved elements |
| transpiration | plants release water into the atmosphere |
| evapotranspiration | combination of evaporation and transpiration used as a measureof the water moving through an ecosystem |
| runoff | water that isn't absorbed by the land but flows directly into streams, lakes and oceans; steeper grades/ less plants = more runoff, which leads to greater evaporation |
| 6 processes that drive the carbon cycle | photosynthesis, respiration, exchange, sedimentation and burial, extraction, combustion |
| macronutrients | organisms need these in relatively large amounts: nitrogen, phosporus, potassium, calcium, magnesium, sulfur |
| limiting nutrient | a lack of this contraints growth (often nitrogen) |
| nitrogen | needed to form amino acids (for proteins) and nucleic acids (DNA/ RNA); 3% body weight of humans; cycle - 1. fixation in soil, 2. assimilation in plants, 3. ammonification |
| biotic nitrogen fixation | only a few organisms can use enzymes to convert N2 to N3 (ammonia) and then to ammonium (NH4+) is the 1st step of nitrogen cycle; cyanobacteria (blue-green algae) and legumes (peas, beans); humans fix more N2 than naturally |
| abiotic nitrogen fixation | lightening strikes in atmosphere, combustion of fires or fossil fuels; N2 to NO3 1- is carried as precipitation |
| ammonification | fungal and bacterial decomposers use nitrogen-containing wastes and dead bodies as a food source and excrete ammonium |
| nitrification | step 4: ammonium -> nitrate (used by organisms) -> nitrite |
| leaching | nitrate is negative and repelled by negative soil so is transported through soil w/ H2O |
| denitrification | in waterlogged soils leaching causes collection of nitrate; bacteria converts it to nitrous oxide (N2O) and then to N2 which goes to atmosphere |
| phosphorus | P is in DNA, RNA and ATP; limiting nutrient for agricultural yields so added to fertilizer |
| phosphorus cycle | no gasous component so atmospheric is in rainwater |
