Ecology Notes

Ecology: The study of the interactions among organisms and their environment.

Environment: Abiotic Factors: non-living factors (rocks, air, sun, water) Biotic Factors: Living factors (plants, animals)

Ecological Organization: Species: one type of living thing Population: a group of a species Community: all the populations in an area Ecosystem: the community and the physical environment Biosphere: the earth

Autotrophs Organisms that make their own food (plants)

Heterotrophs: Organisms that must eat to get energy (animals) Herbivores: eat plants Carnivores: eat animals Omnivores: eat both plants and animals Scavengers: eat dead animals Decomposers: eat dead material/ recycles nutrients

Predator/ Prey Relationship Predator: does the eating Prey: gets eaten

Environmental Limits on Population Size Habitat: Where an organism lives

Niche: Role or job of a species. (reduces competition)

Competition: competing for limited resources (food, water, space)

Growth curve for unlimited or exponential growth.

Finite resources: Limited resources. Limiting factors: any factor that limits population growth. (lack of food, water, space…)

Carrying capacity: The maximum number of species a habitat can support.

Organism relationships Symbiosis: organisms that live and depend on another organism to live. Commensalism: One benefits, one is neutral Mutualism: Both benefit Parasitism: One benefits, one is harmed.

Energy Flow Energy flow: All energy comes from the sun. Plants turn it into food, animals eat plants, animals eat animals… Only about 10% of energy gets passed on to the next organism. 90% gets used up by movement, growth, heat, etc.

Food Chain: a series of organisms through which food energy is transferred.

Food Web: Several interacting food chains. Producers: = autotrophs = plants Consumers: = heterotrophs = eat the food Decomposers: break down food

Energy Pyramid: a diagram showing the amount of energy at the different trophic levels

Biomass Pyramid: diagram showing the amount of mass at each trophic level

Material Cycles Carbon Cycle (carbon, hydrogen, oxygen)

Photosynthesis: light + CO 2 + H 2 O  glucose + O 2 Respiration: glucose + O 2  energy + CO 2 + H 2 O

Water cycle

Nitrogen Cycle: Nitrogen is in proteins N 2 = not useable NO 3, NH 3 = useable by plants and animals

Ecological Succesion: The process by which an existing community is slowly replaced by another community. Primary Succession: starts with rocks Secondary Succession: after a disaster, starts with dirt.

Human Impact Renewable resources: Trees, food Non-renewable resources: Coal, oil, natural gas, metals

Air Pollution From: factories, cars Problems: health problems, acid rain

Water Pollution From: garbage, waste from factories, increase water temperature Problems: chemicals are toxic to animals, heat decreases the amount of oxygen in the water. Nitrates: from sewage… too much algae growth reduces oxygen levels

Biodiversity Creates a more stable ecosystem. More food options for organisms More potential cures for diseases

Loss of Habitats Natural disasters Roads, buildings, pollution

Biological Magnification Poison becomes more concentrated in animals as you go higher in the food chain.

Exotic Species Foreign plants and animals Take food, nests, and other resources from native plants and animals. Have no predators so population levels are uncontrolled.

Acid Rain Caused by Air Pollution Acidic water kills vulnerable organisms such as fish eggs.

Greenhouse Effect vs. Global Warming Greenhouse effect = good Our atmosphere traps heat so we don’t freeze at night Global warming = bad Increased amounts of greenhouse gasses (CO 2, H 2 O, CH 4 ) trap more heat and increase the global temp.

Ozone Layer Ozone = O 3 Located in upper atmosphere Blocks ultraviolet rays which cause cancer CFC’s break down ozone.