___________________________________ORGANISMS POPULATIONS COMMUNITY

BIOLOGY; Miller and Levine; Prentice Hall;2006

SAME SPECIESLIVING TOGETHERIN AN AREA

Ex: “herd”

DIFFERENT POPULATIONS LIVING TOGETHER IN AN AREA

ECOLOGY

_______________________ _____________ECOSYSTEMS BIOMES

IMAGE SOURCES: see last slide

All the organisms that live in a place together with their NON-living environment

Group of ecosystemsthat have same climate and similar communities

BIOSPHERE

The portion of the planet in which all life exists

The scientific study of interactions of organisms with each other and with their environment = ______________

The portion of the planet in which all life exists = _________________(includes land, water, atmosphere)

ECOLOGY

BIOSPHERE

http://jaeger.earthsci.unimelb.edu.au/Images/Topographic/Whole_Earth/Earth_100.jpg

Extends from about 8 km above the Earth’s surfaceto 11 km below the ocean’s surface

WHAT SHAPES AN ECOSYSTEM?

__________________ All the living things an organism interacts with

__________________All the non-living things that

affect an organism

Ex: climate, temperature, sunlightsoil, humidity, wind

BIOTIC FACTORS

ABIOTIC FACTORS

Images from: Pearson Education Inc; Publishing as Pearson Prentice Hall

Habitat vs. Niche• Habitat= the area where an

organism lives.• Niche= physical and biological

conditions necessary for an organism to live; also, what it eats and who eats it.

The Earth is SOLAR POWERED!

_____________ is the main source of energy for life on Earth.

http://www.animation-station.com/smileys/index.php?page=17

SUNLIGHT

ALL LIVING THINGS USE ENERGY

AUTOTROPHS = PRODUCERSCan make their own food

Most autotrophs use _______________ to capture solar energy Main producers on land

= green plants

In water = algaeBIOLOGY; MIller and Levine; Prentice Hall; 2006

PHOTOSYNTHESIS

ALL LIVING THINGS USE ENERGY

HETEROTROPHS = CONSUMERS

________________ = eat only plants

________________ = eat only animals

________________ =eat both plants & animalshttp://gallery.hd.org/_exhibits/natural-science/_more2003/_more09/elephant-eating-greenery-in-Addo-Park-Eastern-Cape-South-Africa-2-WL.jpghttp://personal.ecu.edu/wuenschk/rabbit-wolf.gifhttp://www.rodsguide.com/bears/eating.jpg

HERBIVORES

CARNIVORES

OMNIVORES

HETEROTROPHS = CONSUMERS ________________ = feed on plant & animal remains EX: mites, earthworms, snails, crabs

________________ = break down and absorb

organic matterEX: bacteria & fungi

http://montereybayphotos.com/images/nature/2.jpghttp://www.fwnp.com/bracket-fungi.htm

DETRITIVORES

DECOMPOSERS

Each step in a food chain or web =

_______________

______________ALWAYSmake up the________ trophic level.

http://home.insightbb.com/~g.mager/Pond/Ecosystem.htll

TROPHIC LEVEL

PRODUCERS

FIRST

Lower levels must be

bigger to support the

level above.

Only about_____ of the energy fromeach level is

passedon.

http://home.insightbb.com/~g.mager/Pond/Ecosystem.htll

10%

Some energy is used

for life processessuch as growth,development,movement,metabolism,transport, andreproduction.

The rest islost as ________http://home.insightbb.com/~g.mager/Pond/Ecosystem.htll

HEAT

Ways organisms interact______________________

Between SAME and DIFFERENT kinds of organisms Compete with each other for available resources

__________________________Between DIFFERENT kinds of organisms Hunt and kill other organisms to supply their energy needs

__________________________Between SAME kind of organismsLive together and help each other

__________________________Between DIFFERENT kinds of organisms live in close association with another kind of organism

COMPETITION

PREDATION

SYMBIOSIS

COOPERATION

COMPETITIONOrganisms in an ecosystem have to compete with each other for available resources:

Food Shelter Mates

COMPETITIONIf resources are scarce, some organisms

will starve and populations will decrease.

If resources become more plentiful, populations will increase.

Competition in nature often results in a winner and a loser

. . . SURVIVAL OF THE FITTEST!

If a nutrient is in _____________OR __________________it will LIMIT the growth of thepopulation= _____________LIMITING FACTOR

SHORT SUPPLY

CYCLES SLOWLY

http://www.wspa-international.org/exhibition/gallery/large_DeadKenyan%20droughtSPANA.jpg

During this drought, there was not enough food available and many kangaroosstarved.

Food Chain: simple model of how energy and matter pass through an ecosystem

Food Web: series of interrelated food chains

Trophic Level: each “level” in a food chain

How organisms obtain their energy

• Organisms that produce their own food are called autotrophs

• Autotrophs include organisms that complete photosynthesis and chemosynthesis

• Organisms that obtain nutrients from other organisms are called heterotrophs

• Heterotrophs include those that eat only autotrophs and those that eat other heterotrophs

Producers• Autotrophs- organisms that capture energy from sunlight

or chemicals and use that energy to produce food.• Photosynthesis-

use light energy to create high

energy sugars. • Chemosynthesis-

use chemical energy to produce sugars. (bacteria do this)

Food Chains• A food chain is a series of

steps in which organisms transfer energy by eating, and being eaten.

• Energy always flows in one direction from autotrophs to heterotrophs.

• Arrows show direction of energy flow!

Food Webs• When the feeding relationships

in an ecosystem form a network of complex interactions.

• Trophic level- each step in a food chain or food web. Producers make up the first trophic level, consumers make up the second, third, or fourth. 1P

1C

2C

3C

• Biomass Pyramid- Represents the amount of potential food available for each trophic level in an ecosystem.

• Biomass- The total amount of living tissue within a given trophic level. Measured as grams of organic matter per unit area.

• Pyramid of Numbers- Based on the numbers of individual organisms at each trophic level.

• Energy Pyramid- Only about 10% of the energy available within one trophic level is transferred to organisms at the next trophic level.

• Energy consumed is lost from lifeprocesses and as heat.

100%

10%

1%

Ecological Pyramids

Growth Curves• Logistic

growth occurs when a populations growth slows or stops following a period of exponential growth.

•Exponential growth occurs when the individuals in a population reproduce at a constant rate.

Carrying Capacity• Represents the largest number of

individuals that the environment can support.

• Often labeled “K”

Limiting Factors• Limiting factor is a factor that causes a

population growth to decrease.

• Density Dependent limiting factors depend on population size.ex: competition, predation, parasitism

• Density Independent limiting factors affect all populations, regardless of population size.ex: weather, natural disasters, clear cutting

Human Population Growth

• Demography is the study of human population growth statistics

• Demographers study growth rate, age structure, and geographic distribution

• Unlike other organisms, humans are able to reduce environmental effects on growth by eliminating competition for food, increasing food production, and controlling disease organisms

Effects of birthrates and death rates

• In the United States, declining death rates have a greater effect on total population growth than increasing birthrates

• When fertility rates are high, there is higher human population growth unless the death rate is also high

• The birthrate, death rate, and fertility rate provide clues to determining population growth rate

Other factors that affect population growth

• Age Structure affects population growth because if most people are out of their child bearing years, the fertility rate is low

• Immigration (moving in) and Emigration (moving out) do not affect the total worldwide population but, does affect national population growth rates