The Nature of EcologyThe Nature of Ecology

Ecology is the study of connections in Ecology is the study of connections in the natural world.the natural world.

Ecologists look at interactions among Ecologists look at interactions among organisms, populations, communities, organisms, populations, communities,

ecosystems, and the biosphere.ecosystems, and the biosphere.

1.1.An organism is any form of life. The An organism is any form of life. The cell is the basic unit of life in cell is the basic unit of life in

organisms.organisms.

2.2.Organisms are classified as either Organisms are classified as either eukaryotic or prokaryotic based on the eukaryotic or prokaryotic based on the presence or absence of membrane-presence or absence of membrane-

bound organelles.bound organelles.

3.3. Organisms are classified into Organisms are classified into species, which group organisms similar species, which group organisms similar

to each other together.to each other together.

4.4. Sexually reproducing organisms are classified Sexually reproducing organisms are classified as a species if, under natural conditions, they as a species if, under natural conditions, they can breed with one another and produce live, can breed with one another and produce live, fertile offspring.fertile offspring.

5.5. The tiny microbes rule the world; they are The tiny microbes rule the world; they are unseen by the naked eye but keep the unseen by the naked eye but keep the natural world operating.natural world operating.

6.6.About 1.4 million species have been About 1.4 million species have been identified, but estimates of number of species identified, but estimates of number of species range from 3.6 million to 100 millionrange from 3.6 million to 100 million

population population • Consists of a group of interacting individuals Consists of a group of interacting individuals

of the same species occupying a specific of the same species occupying a specific area.area.

• Genetic diversity explains why these Genetic diversity explains why these

individuals may not behave nor look exactly individuals may not behave nor look exactly alike.alike.

• The habitat is the place where a population The habitat is the place where a population

or an individual usually lives. or an individual usually lives.

• Its distribution or range is the area over Its distribution or range is the area over which a species may be found.which a species may be found.

A communityA community

Represents populations of different Represents populations of different species living and interacting in a species living and interacting in a specific area. specific area.

Consist of all the populations of Consist of all the populations of different species interacting and different species interacting and living in a specific arealiving in a specific area

A network of plants, animals, and A network of plants, animals, and microorganisms.microorganisms.

EcosystemEcosystem

A.A. A community of different species A community of different species interacting with each other and with interacting with each other and with their nonliving environment of matter their nonliving environment of matter and energy. and energy.

B.B. All of the earth’s diverse ecosystems All of the earth’s diverse ecosystems comprise the biosphere.comprise the biosphere.

The Earth’s Life-Support SystemsThe Earth’s Life-Support Systems

A.A. Various interconnected spherical layers make up the Various interconnected spherical layers make up the earth’s life-support system.earth’s life-support system.

B.B. The atmosphere is the thin membrane of air around The atmosphere is the thin membrane of air around the planet.the planet.

C.C. The troposphere is the air layer about 11 miles The troposphere is the air layer about 11 miles above sea level.above sea level.

D.D. The stratosphere lies above the troposphere The stratosphere lies above the troposphere between 11–30 miles; it filters out the sun’s harmful between 11–30 miles; it filters out the sun’s harmful radiation.radiation.

E.E. The hydrosphere consists of the earth’s water, The hydrosphere consists of the earth’s water, found in liquid water, ice, and water vapor.found in liquid water, ice, and water vapor.

F. The lithosphere is the crust and upper mantle F. The lithosphere is the crust and upper mantle of the earth’s soil. It contains nonrenewable fossil of the earth’s soil. It contains nonrenewable fossil fuels,fuels,

G. The biosphere includes most of the G. The biosphere includes most of the

hydrosphere, parts of the lower atmosphere, and hydrosphere, parts of the lower atmosphere, and upper lithosphere. All parts of the biosphere are upper lithosphere. All parts of the biosphere are interconnected.interconnected.

H.H. Ecology’s goal is to understand the Ecology’s goal is to understand the interactions in the earth’s global skin of air, water, interactions in the earth’s global skin of air, water, soil, and organisms.soil, and organisms.

I.I. Sun cycles of matter and Sun cycles of matter and gravity sustain life on Earth.gravity sustain life on Earth.

I.I. 1.1. The one-way flow of high-quality solar The one-way flow of high-quality solar energy through materials and living things energy through materials and living things (as they eat) produces low-quality energy. (as they eat) produces low-quality energy. Energy can’t be recycled.Energy can’t be recycled.

2.2. Matter cycles through parts of the Matter cycles through parts of the biosphere.biosphere.

3.3.Gravity causes the downward movement of Gravity causes the downward movement of chemicals as matter cycles through the chemicals as matter cycles through the earth.earth.

I.I. Sun cycles of matter and Sun cycles of matter and gravity sustain life on Earth.gravity sustain life on Earth.

I.I. 1.1. The one-way flow of high-quality The one-way flow of high-quality solar energy through materials and solar energy through materials and living things (as they eat) produces low-living things (as they eat) produces low-quality energy. Energy can’t be quality energy. Energy can’t be recycled.recycled.2.2. Matter cycles through parts of the Matter cycles through parts of the biosphere.biosphere.3.3. Gravity causes the downward Gravity causes the downward movement of chemicals as matter movement of chemicals as matter cycles through the earth.cycles through the earth.

J.J. Solar energy just passes through Solar energy just passes through the earth as electromagnetic waves; the earth as electromagnetic waves; they warm the atmosphere, they warm the atmosphere, evaporate and recycle water, evaporate and recycle water, generate wind, and support plant generate wind, and support plant growth.growth.

K.K. As solar radiation interacts with As solar radiation interacts with the earth, infrared radiation is the earth, infrared radiation is

produced.produced.

K.K. Greenhouse gases trap the Greenhouse gases trap the heat and warm the troposphere. heat and warm the troposphere.

K.K. This natural greenhouse effect This natural greenhouse effect makes the planet warm enough to makes the planet warm enough to support life. support life.

Energy from the sun supports Energy from the sun supports photosynthesis. photosynthesis.

Living plannetLiving plannet

The earth’s temperatures, The earth’s temperatures, distance from the sun, distance from the sun, and size all produce a livable planet. and size all produce a livable planet.

Its liquid water, orbit from the sun, Its liquid water, orbit from the sun, and its gravitational mass all and its gravitational mass all contribute to sustaining life in this contribute to sustaining life in this natural greenhousenatural greenhouse