4 Why care about ecology?Ecological research provides us with the necessary info. to resolve many of the environmental problems that surround us.
5 We are dependent upon the world’s ecosystems, therefore, we must learn how to keep the environment safe for all living organisms.
6 Biosphere The portion of Earth that supports life Several kilometers below ocean’s surface and several kilometers into the atmosphere
7 Biotic Factors Living things with which an organism interacts Animals, plants, fungi, & microorganisms
8 Abiotic Factors Nonliving factors in an organism’s environment Temperature, rainfall, sunlightAir or water currentsType & acidity of soilAvailability of nutrients
9 PopulationA group of a single species that lives in a given area at the same timeEx: school of fishCompete for same resources
10 Biological CommunityA group of interacting populations that occupy the same geographic area at the same time
11 EcosystemA biological community AND all of the abiotic factors that affect it.
12 BiomeA large group of ecosystems that share the same climate and have similar types of communitiesWe’ll cover more in Ch. 3
13 HabitatAn area where an organism lives.Ex: Tree or a grove of trees
14 Niche The role or position that an organisms has in its environment How the organism meets its needs for food, shelter and reproduction.
15 Predation One organism consuming another organism for food Predator eats the preyEx: Cougar eats a rabbit
16 Symbiotic Relationships Symbiosis - Close relationship that exists when two or more species live togetherMutualism, Commensalism, Parasitism
17 Mutualism Both organisms benefit Ex: Lichens - between fungi and algae Algae provides food for fungi and fungi provide a habitat for the algae
18 CommensalismOne organism benefits, the other is neither helped nor harmedEx: Clownfish and sea anemonessea anemones protect & provide food for the clownfishclownfish neither benefits nor harms the sea anemones
19 Parasitism One organism benefits at the expense of another Ex: Dogs & heartworms, ticks, fleas, tapewormsDo not always kill the host - harm it
20 Plants are primary producers Energy in an EcosystemPlants are primary producersProducers are also called autotrophs (self-feeding)Produces its own food by collecting energy from sunlight or inorganic substances
21 Consumers Consumers cannot collect energy directly from the sun Consumers must eat other organisms in order to obtain energyAnimals and bacteria are consumersAnimals are also called heterotrophic because they must feed on other organisms to obtain energy
22 Heterotrophs Must consume other organisms to get its energy Herbivores CarnivoresOmnivoresParasitesDecomposersDetritivores
23 Herbivores Herbivores obtain energy by eating autotrophs (plants) = Primary (1o) consumers
24 Carnivores Carnivores obtain energy by eating other animals Secondary (2o) or Tertiary (3o) consumersheterotrophs that prey on other heterotrophs
25 OmnivoresOmnivores are animals that eat both plants and animals
26 DetritivoresEats fragments of dead matter in an ecosystem, and returns nutrients to the environmentEx: worms, aquatic insects on stream bottoms
27 DecomposersDecomposers break down dead organisms by releasing digestive enzymesEx: Fungi & bacteria
29 Energy FlowThe source of energy (for most ecosystems) is the sunEnergy and nutrients are passed from organism to organism through the food chain
30 Ultimately, energy will be LOST as HEAT It does not continuously cycleBlack arrowsNutrients, however, continuously CYCLE through food webs and through the geological world.White arrows
31 Trophic LevelsFeeding level in the flow of food energy from producers to the highest level of consumersPrimary (1o), secondary (2o) & tertiary (3o) consumersSee ecological pyramids on p. 44
32 Only 10% of the energy in one trophic level is passed on to the next level The rest is used by the organism or lost as heat
33 Biomass - combined mass of all the organisms in that trophic level As the trophic level increases, biomass decreasesnot everything in the lower levels gets eatennot everything that is eaten is digestedenergy is always being lost as heat
34 Food ChainA simple, straight-line sequence of organisms consuming other organismsGrass grasshopper mouse hawk
35 Food WebComplex feeding relationships that result from interconnecting food chainsSee p.43
37 ReviewWhat factors are included in an ecosystem that are not included in a community?Describe how ecosystems and biomes differ.How is a habitat different from a niche? Example?Compare/contrast food chains and food webs.