Introduction to Ecology - Wikispaces Intro Ecology... · Types of Ecology Ecologist use observations & experiments to test explanations for distributions and abundance of species

Introduction to Ecology

Ecology derives components from each of the Four Big Ideas in Biology

Big Idea 1: The process of evolution drives the diversity and unity of life

Big Idea 2: Biological systems utilize free energy and molecular building blocks to grow to reproduce & to maintain dynamic homeostasis

Big Idea 3: Living systems store, retrieve, transmit, and respond to information essential to life processes

Big Idea 4: Biological systems interact, and these systems and their interactions possess complex properties. Big Idea 4 is where most of our study of ecology is found!

2

Ecology Defined

.

3

Ecology is

the study of

organisms

and their

interactions

with the

environment.

Scroll over the picture to PLAY the animation

Levels of Organization

4

Types of Ecology

Ecologist use observations & experiments to test explanations for distributions and abundance of species.

1. Organismal ecology is the study of physiology and behavior interacting with environmental challenges

2. Population ecology studies the factors impacting the number of individuals of a species in an area

3. Community ecology is the study of how organisms interact with each other and the environment

4. Ecosystem ecology studies the energy flow and chemical cycling in a given area

Types of Ecology

Identify the category of ecological research that would investigate each of the following questions.

1. How do trout select a mate?

(A)Organismal ecology

(B)Population ecology

(C) Community ecology

(D)Ecosystem ecology

Types of Ecology


1. How do trout select a mate?





Types of Ecology


2. What factors control photosynthetic productivity in a tropical rainforest?





Types of Ecology


2. What factors control photosynthetic productivity in a tropical rainforest?





Types of Ecology


3. What factors influence the diversity of species that make up a rain forest?





Types of Ecology


3. What factors influence the diversity of species that make up a rain forest?





Abiotic and Biotic Interactions: The 1st Law of Thermodynamics

12 http://www.sci.uidaho.edu/scripter/geog100/lect/16-ecosystems-biomes/ecosystems-files/ecosystems.htm

Abiotic and Biotic Interactions





Importance of Abiotic Factors

16

Not every organism can live everywhere on Earth

Abiotic factors determine which organisms can survive where:

The Coral Reef is an environment teaming with life, but many organisms would find this environment unsuitable due to its abiotic factors (too much water, temperature, availability of light, etc. )

Importance of Biotic Factors

W. J. Fletcher tested the effects of two algae-eating animals, sea urchins and limpets, on seaweed abundance near Sydney, Australia. In areas adjacent to a control site, either the urchins, the limpets, or both were removed.

EXPERIMENT

80

60

40

20

0

Limpet

Sea urchin

Both limpets and urchins removed

Only urchins removed

Only limpets removed

August 1982

February 1983

August 1983

February 1984

Control (both urchins and limpets present)

Seaw

eed

co

ver

(%)

Removing both limpets and urchins or removing only urchins increased seaweed cover dramatically.

Almost no seaweed grew in areas where both urchins and limpets were present, or where only limpets were removed.

Seaw

eed

co

ver

(%)

100

Macroclimate

consists of patterns on

the global, regional,

and landscape level

Microclimate consists

of very fine patterns,

such as those

encountered by the

community of

organisms underneath

a fallen log

18

Earth’s Climate Varies By Latitude & Season

And Is Changing Rapidly

19



•Seasonal variations of light and temperature

increase steadily toward the poles

•Seasonality at high latitudes is caused by the tilt of

Earth’s axis of rotation and its annual passage

around the sun

•Belts of wet and dry air straddling the equator shift

throughout the year with the changing angle of the

sun

•Changing wind patterns affect ocean currents

•

• Global Climate Change

• Changes in Earth’s climate can profoundly

affect the biosphere

• One way to predict the effects of future global

climate change is to study previous change

• As glaciers retreated 16,000 years ago, tree

distribution patterns changed

• As climate changes, species that have difficulty

dispersing may have smaller ranges or could become extinct

20



Homeostasis

• Organisms must maintain homeostasis, a steady-state internal environment, despite changes in the external environment.

• Organisms respond to abiotic factors in 1of 2 ways:

1. Regulators maintain a nearly constant internal environment, despite external conditions

2. Conformers allow internal environment to vary - This occurs in organisms whose environments remain relatively stable

22

EURASIA

AFRICA

SOUTH AMERICA

INDIA

135 million years ago

Present 65 million years ago

225 million years ago

120° 80° 0°

120° 120°

120°

80° 80° 80° 80° 40°

40° 120° 120°

120°

GONDWANALAND GONDWANALAND

120°

LAURASIA LAURASIA

ANTARCTICA ANTARCTICA

AUSTRALIA AUSTRALIA

NORTH AMERICA NORTH AMERICA

MADA- GASCAR

MADA- GASCAR

Historical Biogeography

Biogeography: Leopard Distribution

Biogeography: Leopard Distribution

• Leopards have the largest distribution of any wild cat, occurring widely in eastern and central Africa, although populations have shown a declining trend and are fragmented outside of sub-Saharan Africa.

• Within sub-Saharan Africa, the species is still numerous and even thriving in marginal habitats where other large cats have disappeared.

• But populations in North Africa may be extinct

Biogeography

• Serves as a starting point to understanding limits on distribution of species

Species absent because

Yes

No

Dispersal limits

distribution?

Yes

No

Yes

No

Biogeography & Distribution of Species



Yes

No

Dispersal limits

distribution? Behavior limits

distribution?

Yes

No

Yes

No

Area inaccessible or insufficient time

Biogeography



Yes

No

Dispersal limits


distribution? Biotic factors (other species)

limit distribution?

Yes

No

Yes

No


Habitat selection

Biogeography



Yes

No

Dispersal limits


distribution? Biotic factors (other species)

limit distribution? Abiotic factors

limit distribution?

Yes

No

Yes

No


Habitat selection

Predation, parasitism, competition, disease

Biogeography



Yes

No

Dispersal limits


distribution? Biotic factors

(other species) limit

distribution? Abiotic factors

limit distribution?

Yes

No

Yes

No


Habitat selection

Predation, parasitism, competition, disease

Water Oxygen Salinity pH Soil nutrients, etc.

Temperature Light Soil structure Fire Moisture, etc.

Chemical factors

Physical factors

Ecology: The Big Picture

31

1. Biological systems interact, and these systems and their interactions possess complex properties.

2. Abiotic and biotic factors influence populations, communities, ecosystems, and the biosphere.

3. Over time species have adapted, died, or moved to more suitable environments.

Created by: Susan Ramsey Virginia Advanced Study Strategies Notable contributions by S. Meister

Documents

Introduction to Ecology - Wikispaces Intro Ecology... · Types of Ecology Ecologist use observations & experiments to test explanations for distributions and abundance of species