Ecology Introduction The Biosphere

Define Ecology. The study of interactions between organisms and their environment

Select one thing in the picture and remove it. What would change?

Biosphere Combined portions of the planet in which all life exists Includes land, water, air, atmosphere From 8 km above Earth  11 km below ocean surface

Compare biotic and abiotic factors. Biotic factors: all organisms inhabiting the environment, adapted to its particular part of the world Abiotic factors: nonliving parts of the environment, can determine which species survive Biotic Abiotic

Species Group of organisms that can breed and produce fertile offspring

Most mules are sterile. Sterile hybrids are not species in their own right. A mule is the offspring of a male donkey (jack) and a female horse (mare). Horses and donkeys are different species, with different numbers of chromosomes.

Liger hybrid cross between a male lion and a female tiger Males = sterile; some females have reproduced

Population Groups of individuals/same species that live in the same area

Community Assemblages of different populations living in a defined area

Ecosystem Collection of all living organisms that live in a particular place together with their non-living (AKA physical) environment

Biome Group of Ecosystems that have the same climate and similar dominant communities

Biosphere Combined portions of the planet in which all life exists Includes land, water, air, atmosphere (biotic and abiotic) From 8 km above Earth  11 km below ocean surface

Pop Quiz Think of the wooded area behind the school parking lot… List several biotic factors Now list several abiotic factors

How is Ecology Studied? Observation Experimentation Modeling

Energy Flow

Sunlight The main source of Energy for life on earth

Autotroph Aka Producer Use E from environment to fuel assembly of simple inorganic compounds into complex organic molecules Plants, some algae, certain bacteria Photosynthesis or Chemosynthesis

Photosynthesis Harness solar E to power chem reax that converts CO2 and H2O  O2 and sugars This process removes CO2 and add O2 to Earth’s atmosphere Plants: main autotrophs on land Algae: main autotrophs upper layer of ocean and in fresh water Photosynthetic bacteria: (most common = cyanobacteria) important in tidal flats and salt marshes (wet ecosystems)

Chemosynthesis Uses chemical E to produce carbs Usually done in the absence of light (e.g.: volcanic vents ocean floor) Performed by different types of bacteria

Heterotrophs Aka consumers Rely on other organisms fro E & food supply Animals, fungi, many bacteria

Compare the types of feeding relationships. Autotrophs (producers): self-feeders; produce own food; example: plants Heterotrophs (consumers): depend on others for food Herbivore: eat only plants Carnivore: eat only meat Omnivore: eat both plants and meat herbivore What are you? omnivore carnivore

Decomposers: break down and absorbs nutrients from dead organisms (Ex: fungi) Detritivores: feed on dead material called detritus (scavengers)

Herbivore: cows, deer, caterpillars Carnivore: snakes, dogs, owls Omnivore: humans, bears, crows Detritivore: (eat dead matter, plant & animal remains) mites, earthworms, snails, crabs Decomposers: (aka saprophytes) bacteria & fungi

Energy flows through ecosystems in a ONE WAY direction SunAutotrophHeterotroph Food Chain: series of steps in which organisms transfer E by eating OR by being eaten Producersprimary consumerssecondary consumerstertiary consumers Decomposers (aka saprotrophs), detritivores & parasites can occupy any level of food chain

Food Chain Series of steps in which organisms transfer E by eating OR by being eaten Direct line sequence

Food Web overlapping food chains Network of complex interactions

Trophic Levels Each consumer depends on trophic level below it for E

Pop Quiz

Ecology Pyramids Shows the relative amounts of E or matter within each tropic level in a food chain (or food web)

Energy Pyramid Shows relative E available at each trophic level Only approx !0% of E available within one level is transferred

Pyramid of Biomass Amount of living organic matter at each trophic level Biomass = total amount of living tissue within a trophic level

Pyramid of Numbers Relative number of individual organisms at each trophic level

Food web: more complicated than chains, shows more than one food source for each organism Energy pyramids: show decreasing amounts of energy, biomass, and number of individuals as you move up the pyramid

The Flow of Energy: Higher Trophic Levels Three hundred trout are needed to support one man for a year.  The trout, in turn, must consume 90,000 frogs, that must consume 27 million grasshoppers that live off of 1,000 tons of grass. -- G. Tyler Miller, Jr., American Chemist (1971)

Compare Food chains, food webs and energy pyramids Food Chains: model showing movement of energy through ecosystem using arrows to show “what eats what” Trophic levels: Primary consumer: eat plants Secondary: eats primary Tertiary (3rd): eats secondary Label the parts of the food chain on your notes!