THE BIOSPHERE“LIFE BALL”

Unit 3

What is Ecology?

The Scientific study of the interaction among organisms and between organisms and their environment.Ernst Harckel coined the term ecology

based on the Greek word for house.Harckel saw the earth and its various

environments as “houses” with each of its organisms playing a role (interacting) to keep the “houses” going.

Houses….. Nature’s “houses” come in many sizes from single

cells to the entire planet. The largest of nature’s houses is called a

biosphere. Biosphere- the part of earth in which life exists

including land, water(11km), and air or atmosphere(8km).

Levels of Organization

Biosphere (largest)Biome-group of ecosystems that have the same

climate and dominant communities.○ Ecosystem-collection of all the organism that live in a

particular place, together with non-living things.Community-assemblage of different populations

that live together in a defined area.- Population-group of individuals of the same

species that live in the same area.- Individual (species)-a group of organisms so

similar that they can breed and produce fertile offspring. (smallest)

How do ecologists study the biosphere??

Three Ecological Methods of Study.Observing: What lives here? How many? Etc.Experimenting: Imitation of natural environmentsModeling: Create models using computer or mathematical

formulas

Energy Flow in the Biosphere Sunlight: The main source of energy for all

living things on earth. Producers: An organism that can capture

energy from the sun and use it to produce food (autotroph).Photosynthesis- uses light to make food

(Phototrophs)Chemosynthesis- uses inorganic molecules

(Chemotrophs) Consumers: An organism that relies on other

organisms for its energy (heterotroph).

Consumers Cont….

Types of HeterotrophsHerbivores- Eat only plants (ex. Cow).Carnivores- Eat only other animals (ex.Owl).Omnivores- Eat both plants and animals (ex.

Humans).Detritvores- Feed on detritus, dead or

decaying materials (snails, crabs).Decomposers- Breaks down dead organic

matter (bacteria). Sunlight Autotrophs (producers) Heterotrophs (consumers)

Energy continued…. Feeding Relationships: Energy flows

through an ecosystem in one direction from the sun or inorganic compounds to autotrophs and then to heterotrophs.Food Chain: Series of steps in an

ecosystem in which organisms transfer energy by eating and being eaten.

Food Web: Network of complex interactions formed by the feeding relationships among organisms in an ecosystem.○ Trophic Levels The steps in a food chain or

web.

Food Web Ex.

Ecological Pyramids A diagram that shows the relative

amounts of energy or matter within each trophic level in a food chain.Energy pyramid- shows relative amount of

energy available at each trophic level.Biomass pyramid-total amount of living

tissue within a trophic level.

Cycle of Matter

Recycling in the biosphere- Unlike the one-way flow of energy within a biosphere, matter is recycled. Water CycleNutrient Cycle (Biochemical cycles)

○ Carbon Cycle (key ingredient in living things)○ Nitrogen Cycle

Needed to make amino acids78% of the Earth’s air

○ Phosphorus CycleEssential for DNA and RNA

Water Cycle

Evaporation- Liquid Gas Transpiration- evaporation from the leaves of plants Precipitation- The release of condensed liquid from clouds Condensation- Gas Liquid Runoff- Precipitation runs along surface of ground until it enters a

river or stream. Seepage- Rain water seeps into the soil and becomes ground water.

Nutrient Cycle

Carbon Cycle Nitrogen Cycle

Four Types of Processes that Impact the Biosphere Biological-Take up carbon and release

oxygen (ex. photosynthesis & respiration) Geochemical-Erosion and volcanic activity

that release carbon dioxide. Mixed Biogeochemical- Decomposition of

dead organisms, underground pressure that leads to formation of coal.

Human Activities- Release CO2 into the air by cutting and burning forests, burning fossil fuels.

Nutrient Limitations

Primary ProductivityRate at which producers make organic matter.Controls the amount of nutrients available.

Limiting NutrientsScarce nutrients, limits organism’s growth.Farmers use fertilizer to try and fix this

problem.Can have sudden increase in limiting nutrients

usually in aquatic ecosystems due to runoff.○ Algae Bloom