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…

Proboscis Monkey Thompson’s Gazelle

Parrot Mushroom

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

Solar energy fuels life processes and is dissipate back to space as heat (low quality energy).

Cycling of matter or nutrients 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