2 ECOLOGY The study of interactions among organisms & their environment Ecologists divide environmental factors that influence organisms into 2 groups: ABIOTIC and BIOTIC.
3 ABIOTIC NONLIVING PARTS OF THE ENVIRONMENT Ex: Water, light, temperature, air, soilAir is a mixture of 3 main gases: oxygen, carbon dioxide, & nitrogen (used by plants & animals)
4 BIOTIC Living or once-living organisms in the environment Can be arranged into levels of organization:
5 1. organism1 individual from a populationExample: catfish
6 2. PopulationAll the individuals of one species that live in the same area at the same time.Example: All the catfish living in a lake at the same time
7 3. communityPopulations of different species that interact in some wayExample: Population of bass and all the species they interact with it
8 4. ecosystemAll the communities in an area & the abiotic factors that affect themExample: lake, pond, coral reef, forest, etc.
9 5. BiomeLarge region with plants & animals well adapted to soil & climate of the regionExample: Mountain, rainforests, tundra, desert, grasslands, temperate forests (where we live)
10 6. biosphereAll the ecosystems on earth; the part of the earth that supports lifeExample: Top part of the earth’s crust, all the waters that cover the Earth’s surface, the surrounding atmosphere, & all the biomes.
11 Energy flow through an ecosystem Energy transfer: all energy comes from the sun and is transferred from one organism to another.Most of the interactions among members of different species occur when one organism feeds on another
12 When one organism is food for another organism, some of the energy in the first organism (the food) is transferred to the second organism (the eater).
13 ProducersOrganisms that take in & use energy from the sun or some other source to produce food.Examples: algae & plants
14 Consumers Ex.: frog, lion Organisms that take in energy when they feed on producers or other consumers.1st level consumer: eats the producers2nd level consumer: eats the 1st level consumerEx.: frog, lion
15 Decomposers Ex.: bacteria, mushrooms (fungi) Organisms that take in energy (food) from dead organisms breaking down the remains of organisms & returning it to the soil so other plants can grow.Ex.: bacteria, mushrooms (fungi)
16 Niche: a species’ specific role in its community (habitat) Ex. A red fox is a predator that feeds on small mammals, amphibians & insects in its habitat
17 Movement of energy through a community can be diagrammed as a food chain or food web.
18 Food chainSimple way of showing how energy passes from one organism to another.Usually 3 or 4 links
19 Example of food chain:Water plant insects bluegill bassGrass grasshopper frog snake owl
20 Food web Series of overlapping food chains that exist in an ecosystem More complete model of feeding relationships.
21 Energy pyramidCompares energy available at each level of the food chain in an ecosystemAs you move from level to level, energy decreases.
22 Energy enters most ecosystems in the form of heat from the sun. Then it’s transferred into chemical energy by producers then passed to consumers as food.Then given back off as heat.
23 Cycles of matterMany important materials (water, carbon, & nitrogen) make up your body & cycle through the environment.
24 1. Water cycleProcess of evaporation, condensation, & precipitation
25 2. Carbon cyclePlants absorb CO2 & combines it with water for their needsIn photosynthesis, the plants use the carbon atoms from the CO2 to make sugars.
26 Carbon cycle continued… Animals eat the producers & other consumers and return the CO2 back into the air through respiration.Animals & plants die then carbon is returned back to soil during decomposition.
27 Nitrogen Cycle….Nitrogen is “fixed” by bacteria in the soil then absorbed by plants & animals for their use.
28 Major Biomes of the world: 1. Aquatic: includes freshwater and saltwater (oceans)2. Desert:2 Kinds: hot/dry(little rain) and cold (snow), few plants grow in either and few animals live in them Ex. Great Basin in Utah, Sahara Desert in Northern Africa
29 3. Forest (rainforest, deciduous): lots of different vegetation & animals that live there, climate can be moderate temperatures or really coldrainforestDeciduous forest
30 4. Grasslands: mainly grasses, flowers and herbs grow here (not a lot of trees), animals, climate varies (can be humid/wet and hot summer/cold winter) Ex. Plains of Africa5. Tundra- coldest biome, few plants and few animals, located in the Northern Hemisphere