Intro to ECOLOGY

(Chapter 33)

33.1

The study of the interaction of organisms with each other and their physical environment

Organisms are organized into: Populations – ex: Perch

(Members of a species living in an area)

Communities –ex: Perch, Walleye, Algae (All the populations in an area)

Ecosystems –ex: Fish, Algae, Rocks, water (A community and its physical environment) includes biotic and abiotic factors

Biomes –ex:Tundra, Rainforest (A large group of similar ecosystems containing distinct

types of plants, animals, etc…determined by climate)

Biosphere (all the communities on Earth whose members exist in air,

water, and on land)

ONE species!

More than ONE species!

Adds NONliving components!

How do populations grow?

BIOTIC POTENTIAL: highest possible per capita rate of increase for a population Per capita rate of increase= (Births-Deaths) / # of

individual LIMITING FACTORS: (create environmental

resistance) Biotic-living parts of the ecosystem

vegetation, etc Abiotic – nonliving parts of the ecosystem

Precipitation Temperature Inorganic nutrients

Exponential Growth…J curves

Has two phases: Lag phase: growth is

slow because the population is small

Exponential Growth Phase: growth is accelerating, and the population is exhibiting BIOTIC POTENTIAL.

Cannot usually continue for long because of …

Environmental Resistance & Carrying Capacity

Environmental Resistance: all the environmental conditions that prevent populations from reaching their biotic potential

Ex: limited food supply, accumulation of waste, predation, competition…(biotic and abiotic limiting factors)

MOST populations taper off around their…

Carrying Capacity: # of individuals the environment can normally support

We call this kind of growth…

Logistic Growth

This creates an “S shaped curve”

Four phases: Lag Exponential growth Deceleration phase (pop

growth slows) Stable equilibrium

phase/stationary phase (births and deaths start to even out)

1. Where is the carrying capactiy in this curve?

…Survivorship Curves p. 683…Human Population Growth

developed vs. less developed countries

…Age distributions

Discussion Topics…

What do the wolves in this picture represent?

Popul

atio

n

Eco

syst

em

Com

munity

Bio

me

89%

5%5%0%

1. Population

2. Ecosystem

3. Community

4. Biome

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20

21 22 23 24

Which of the following could be the wolves COMMUNITY?

All

the

popula

tions

o...

The

wol

ves,

and th

e...

The

wol

ves

and

the

soil

16%5%

79%1. All the populations of wolves in that biome

2. The wolves, and the moose

3. The wolves and the soil

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20

21 22 23 24

Everything in this picture would add up to a/an…

Popul

atio

n

Bio

me

Eco

syst

em

Spec

ies

0% 0%

95%

5%

1. Population

2. Biome

3. Ecosystem

4. Species

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20

21 22 23 24

The Atmosphere, Water and Soil pictured below are examples of…

.

.

.

.

.

.

Bio

tic F

acto

rs

Abio

tic F

acto

rs

Eco

syst

em

Popul

atio

n

Com

munity

5%

74%

0%0%

21%

1. Biotic Factors

2. Abiotic Factors

3. Ecosystem

4. Population

5. Community

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20

21 22 23 24

The rabbit and wolf below represent a/an…

.

.

.

.

.

.

Bio

tic F

acto

rs

Abio

tic F

acto

rs

Eco

syst

em

Popul

atio

n

Com

munity

89%

6%

89%

17%11%

1. Biotic Factors

2. Abiotic Factors

3. Ecosystem

4. Population

5. Community

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20

21 22 23 24