Ecology

Ecology Ecology is the study of interactions between different kinds of living things and their environment.

Why is Ecology Important?

Why care about ecology? Ecological research provides us with the necessary info. to resolve many of the environmental problems that surround us.

We are dependent upon the world’s ecosystems, therefore, we must learn how to keep the environment safe for all living organisms.

Biosphere The portion of Earth that supports life Several kilometers below ocean’s surface and several kilometers into the atmosphere

Biotic Factors Living things with which an organism interacts Animals, plants, fungi, & microorganisms

Abiotic Factors Nonliving factors in an organism’s environment Temperature, rainfall, sunlight Air or water currents Type & acidity of soil Availability of nutrients

Population A group of a single species that lives in a given area at the same time Ex: school of fish Compete for same resources

Biological Community A group of interacting populations that occupy the same geographic area at the same time

Ecosystem A biological community AND all of the abiotic factors that affect it.

Biome A large group of ecosystems that share the same climate and have similar types of communities We’ll cover more in Ch. 3

Habitat An area where an organism lives. Ex: Tree or a grove of trees

Niche The role or position that an organisms has in its environment How the organism meets its needs for food, shelter and reproduction.

Predation One organism consuming another organism for food Predator eats the prey Ex: Cougar eats a rabbit

Symbiotic Relationships Symbiosis - Close relationship that exists when two or more species live together Mutualism, Commensalism, Parasitism

Mutualism Both organisms benefit Ex: Lichens - between fungi and algae Algae provides food for fungi and fungi provide a habitat for the algae

Commensalism One organism benefits, the other is neither helped nor harmed Ex: Clownfish and sea anemones sea anemones protect & provide food for the clownfish clownfish neither benefits nor harms the sea anemones

Parasitism One organism benefits at the expense of another Ex: Dogs & heartworms, ticks, fleas, tapeworms Do not always kill the host - harm it

Plants are primary producers Energy in an Ecosystem Plants are primary producers Producers are also called autotrophs (self-feeding) Produces its own food by collecting energy from sunlight or inorganic substances

Consumers Consumers cannot collect energy directly from the sun Consumers must eat other organisms in order to obtain energy Animals and bacteria are consumers Animals are also called heterotrophic because they must feed on other organisms to obtain energy

Heterotrophs Must consume other organisms to get its energy Herbivores Carnivores Omnivores Parasites Decomposers Detritivores

Herbivores Herbivores obtain energy by eating autotrophs (plants) = Primary (1o) consumers

Carnivores Carnivores obtain energy by eating other animals Secondary (2o) or Tertiary (3o) consumers heterotrophs that prey on other heterotrophs

Omnivores Omnivores are animals that eat both plants and animals

Detritivores Eats fragments of dead matter in an ecosystem, and returns nutrients to the environment Ex: worms, aquatic insects on stream bottoms

Decomposers Decomposers break down dead organisms by releasing digestive enzymes Ex: Fungi & bacteria

Energy Flow The source of energy (for most ecosystems) is the sun Energy and nutrients are passed from organism to organism through the food chain

Ultimately, energy will be LOST as HEAT It does not continuously cycle Black arrows Nutrients, however, continuously CYCLE through food webs and through the geological world. White arrows

Trophic Levels Feeding level in the flow of food energy from producers to the highest level of consumers Primary (1o), secondary (2o) & tertiary (3o) consumers See ecological pyramids on p. 44

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

Biomass - combined mass of all the organisms in that trophic level As the trophic level increases, biomass decreases not everything in the lower levels gets eaten not everything that is eaten is digested energy is always being lost as heat

Food Chain A simple, straight-line sequence of organisms consuming other organisms Grass grasshopper  mouse  hawk

Food Web Complex feeding relationships that result from interconnecting food chains See p.43

Review What 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.