Environmental Science Unit 2
Sections 3-1 to 3-3, Fall 2010
Bell-Work

Describe several biotic and abiotic factors in your life

Describe two ways microbes influence your life.

In your own words, describe a species.
Bell-Work Conversions

Convert the following:

1.45 x 105 J/s  Kj/Min

2.45 x 102 Kcal/m2 -> Kcal/km2

37 g/day -> kg/year
Cell Theory

All living things are made of cells
All cells come from other cells
Cells are the building blocks of life

Two different types




Prokaryotic
Eukaryotic
Ecology

Comes from the Greek word oikos meaning “house”

The study of how organisms interact with one another
and their abiotic (non-living) environment.

We focus on organisms and up.
Biological Species Concept

A species is a related group of organisms whose
members can freely interbreed, in nature…
Parrot Mushroom
Proboscis Monkey
Thompson’s Gazelle
Population

A group of organisms of the same species occupying
a given area.Variation in a population is called genetic
diversity
Field of Poppies
Other Populations
Community

A community is defined
as a group of
interacting species
living in the same
place.
Ecosystem

All the biotic and abiotic factors in an area working
together.


Biotic – Living things
Abiotic – Non-living things
Biosphere – The Earth
Atmosphere

Thin envelope of gases surrounding Earth’s surface.

Troposphere – extends ~17 km up, “weather” producing
region of the atmosphere.




78% Nitrogen
21% Oxygen
1% CO2, H2O, CH4 (greenhouse gases)
Stratosphere – upper layer containing most of the ozone
(O3)
Hydrosphere and Geosphere

Hydrosphere





Liquid water
Ice caps
Permafrost
Water vapor
Geosphere



Core
Mantle
Crust
Biomes – large regions with distinct climates

Aquatic life zones

Freshwater life zones


Lakes and streams
Marine life zones



Coral reefs
Estuaries
Deep ocean
Factors Sustaining Life

One-way flow of high quality energy


Cycling of matter or nutrients


Solar energy fuels life processes and is dissipate back to space
as heat (low quality energy).
Fixed supplies of nutrients must be recycled.
Gravity

Helps hold the atmosphere in place and enables cycling
Solar Energy

UV, visible, and IR energy

Radiation





Absorbed by ozone
Absorbed by the earth
Reflected by the earth
Radiated by the atmosphere as heat
Natural greenhouse effect – keeps the earth warm
enough to support life.
Abiotic and Biotic
Abiotic – non-living
Biotic – living or
once living
Range of Tolerance

Tolerance in physical and chemical variation in the
environment; Figure 3-10.
Limiting Factors

Factors more important than others in regulating
population growth (carrying capacity)
Trophic Levels



Omnivores – eat from multiple trophic levels
Decomposers – bacteria & fungi; release nutrients from
dead organisms; use secretions
Detritus Feeders – eat dead organisms and waste
Energy Flow