ECOLOGY

What is ecology?Ecology-

the scientific study of interactions between organisms and their

environments, focusing on energy transfer

It is a science of relationships.

What is the environment? Definition:

All external conditions and factors (living and nonliving) that affect an organism or other specified system during its lifetime

The environment is made up of two factors:

Biotic factors- all living organisms inhabiting the Earthex. How organisms interact/effect each other

Abiotic factors- nonliving parts of the environment temperature Soil Sunlight water/moisture air currents/wind Severe disturbances

Temperature Temperature 0-50oC is the narrow range of

temperatures that can support life Too hot: above 50…important enzymes DENATURE Too cold: metabolism slows down…what is metabolism?

(review notes from beginning of year!) Set of chemical reactions that help break down and

build up molecules to get energy for life

Organisms have made adaptations to extreme environments Prokaryotes in deep sea vents (extreme heat) Prokaryotes in frigid arctic waters (extreme cold)

Soil

Product of abiotic forces (ice, rain, and wind) and biotic forces (microorganisms, plants, and earthworms) on rocks and minerals of Earth’s crust

Effects plants that grow in areas Dry, nutrient poor soil dominated by blue stem

grasses with long roots to obtain scarce moisture in soil and narrow leaves that prevent excessive water loss

Soil/sand in aquatic environments also impacts ecosystem

Soil can be acidic or basic, nutrient rich or nutrient poor

This influences plants that grow in area, which influence organisms that live there

Sunlight

Energy source for ALL organisms (except chemosynthetic organisms)

Terrestrial and aquatic Penetrates top 200 m of the surface…affects algae

Forests trees prevent sunlight from reaching the bottom…varying amounts of sunlight creates microhabitats…what does that mean?You get a Habitat with conditions different from the larger surrounding environment

PHOTOSYNTHESIS is HUGE!!!

Water and Moisture Dissolves gasses Universal solvent (review 4 major

properties of water) Organisms make adaptations to prevent

water loss (needles instead of leaves on trees and a waxy cuticle)

Air currents and wind

Affects distribution Moves clouds which carry precipitation Stirs up water which mixes up the

nutrients in lakes and streams Spreads pollen and seeds of plants

(improves genetic diversity!!!)

Severe Disturbances Fires, hurricanes, droughts, Floods and volcanic

eruptions Some occur frequently and organisms have

made evolutionary adaptations (prairie grasses) Some are infrequent (volcanic eruptions) and

organisms have no voluntary adaptations

Organism

Population

Community

Biosphere

Ecosystem

Levels of

Ecology!

Organism- any unicellular or multicellular form exhibiting all of the characteristics of life, an individual.

•The lowest level of organization

Population-a group of organisms of one species living in the same place at the same time that interbreed and compete with each other for resources (ex. food, mates, shelter)

Community- several interacting populations that inhabit a common environment and are interdependent.

Ecosystem- populations in a community and the abiotic factors with which they interact (ex. marine, terrestrial)

Biosphere- life supporting portions of Earth composed of air, land, fresh water, and salt water.

•The highest level of organization

“The ecological niche of an organism depends not only on where it lives but also on what it does. By analogy, it may be said that the habitat is the organism's ‘address’, and the niche is its ‘profession’, biologically speaking.”

Odum - Fundamentals of Ecology

Niche Each species unique living arrangement

in a community “Role”

Think about a specific position player on a team i.e. pitcher on a baseball team

Ex. Lizards in a rainforest Includes:

Habitat Food sources Time of day organism is most active

Rules, rules, rules Fundamental rule in ecology

Competitive Exclusion Principle Russian biologist G.F. Gause

Paramecium caudatum vs. Paramecium aurelia Separately, both thrive in a culture P. aurelia could gather food more quickly than the P. caudatum, therefore, if they are grown together, P. aurelia will thrive while P. caudatum will die out

2 species so similar in requirements that the same resource limits both population’s growth, and one species may succeed over another

No two species can occupy the same niche in the same habitat and the same time

Prevents un necessary competition

20

Competitive Exclusion:

The Ciliate Paramecium over 24 d

Grown inSeparateFlasks

Grown inthe SameFlask

Habitat vs. NicheNiche - the role a species plays in a community (job)

Habitat- the place in which an organism lives out its life (address)

Habitat vs. Niche

A niche is determined by the tolerance limitations of an organism, or a limiting factor.

Limiting factor- any biotic or abiotic factor that restricts the existence of organisms in a specific environment.

Examples of limiting factors (things that limit the population of species in a habitat)

•Amount of water•Amount of food•Temperature

Habitat vs. Niche

Still confused?

Uneven Heating of Earth’s Surface Earth rotates on an axis (23.5’) So sunlight hits Earth at different angles Creates Climate Zones

Tropics Region between Tropic of Cancer (23.5’N) and

Tropic of Capricorn (23.5’S) Most direct sunlight

Temperate Zones Latitudes between the Tropics and the Polar Zones Seasonal changes; no extreme heat or cold

Polar Zones Region north of the Arctic Circle (66.5’N) and South

of the Antarctic Circle (66.5’S) Least amount of direct sunlight

These climate zones are important and create BIOMES

Wind, Precipitation and Currents Our planet's rotation produces a force on all

bodies moving relative to the Earth Due to Earth's approximately spherical

shape, this force is greatest at the poles and least at the Equator.

"Coriolis effect” the force that causes the direction of winds and ocean currents to be deflected

Northern Hemisphere wind and currents deflected toward the right

Southern Hemisphere wind and currents deflected to the left.

Climate vs. Weather

Weather Day-to-day conditions of Earth's atmosphere

precipitation, humidity, temperature, etc. Changes every day

Climate The average, year-after-year, conditions (temperature and precipitation) that prevail in a specific

region Microclimate

Climate in a specific area that varies from the surrounding climate region Ex. The burrow of a Kangaroo rat in the New Mexico desert (dark and cool)

Biomes Terrestrial ecosystems that cover a large

region of Earth Characterized by communities of plants

and other organisms adapted to the climate and other abiotic factors

Major Terrestrial Biomes

Tropical Rainforest Tropical Dry Forest Tropical Savannah Desert Temperate Grasslands (Prairie)

Chaparral /shrubland Temperate Deciduous forest North Western Coniferous Boreal Forest/Taiga Tundra