Ecology

Ecology The study of interactions among & between organisms and their environment.

Levels of Ecology Species: group of organisms that can produce fertile offspring. Populations: group of the same species Communities: group of different populations Ecosystem: all of the organisms living in a particular place & their nonliving environment Biome: group of ecosystems with the similar climate and communities Biosphere: portions of the planet where life exists.

Energy Flow: Producers Sunlight is the main energy source Autotrophs: use energy from the environment to assemble simple inorganic compounds into complex organic molecules. Photosynthesis - use light energy CO2 + H2O  O2 + sugars Chemosynthesis - use chemical energy to produce carbohydrates volcanic vents on the deep ocean floor, hot springs in Yellow Stone park

Energy Flow: Consumers Heterotrophs: rely on other organisms for their energy and food supply Herbivores: only plants; cows, caterpillars, deer Carnivores: eat animals; snakes, owls, cats Omnivores: both plants and animals; humans, bears, crows Detritivores: plant and animal remains and other dead matter; mites, earthworms, snails, and crabs Decomposers: breaks down organic matter; bacteria and fungi

Feeding Relationships Energy flows one direction in an ecosystem sun/inorganic compound (autotroph)producers  (heterotroph) consumers Food Chain: steps in which organisms transfer energy by eating or being eat Grass antelope  coyote

Food Web complex relationship in an ecosystem that links all food chains together Trophic Level – each step in a food chain Producers – first level Consumers – second, third, or higher level Each consumer depends on the level below for energy

Food Web

Ecological Pyramids shows the energy/matter in each trophic level Energy Pyramid: ~10% of the energy in each tropic level is transferred to the next level Most is used for life processes; respiration, reproduction, movement, & some is released as heat

Biomass Pyramid Biomass: amount of living tissue within a given tropic level (g organic matter/area) Biomass Pyramid: amount of potential food available for each trophic level

Pyramid of Numbers number of individual organism at each trophic level Exception: forest: a single tree has many organisms, insects, that live in/on it and there are fewer producers than consumers in a forest