intro to ecology part 1
TRANSCRIPT
ECOLOGY
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 the 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)
What is ecology?
Ecology- the scientific study of interactions between organisms and their environments, focusing on energy transfer
It is a science of relationships.
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?Habitat with conditions different from the larger
surrounding environment PHOTOSYNTHESIS
Water and Moisture Dissolves gasses Universal solvent 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
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
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
Habitat vs. Niche
Niche - 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-
•Amount of water•Amount of food•Temperature
Habitat vs. Niche
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
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
Temperate Zones Latitudes between the Tropics and the Polar Zones Seasonal changes; no extreme heat or cold
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)