Ecology

Introduction to

Ecology

Ecology

 The study of interactions among organisms

and between organisms and their environment,

or surroundings.

 Discovery Channel :: Planet Earth :: Portrait of

the Planet

Ecosystem

 Living and non-living

factors in the same place

at the same time

 Ex:

fish tank, pond, forest,

etc.

Organization of the Ecosystem









Go to

Section:

Biotic Factors

 Living factors that has an effect on another

living organism

 Example for a bird:

Trees, other birds, insects, worms, etc

Abiotic Factors

 Non-living factors

that has an effect

on a living

organism

 Example for a

bird:

Water, wind,

temperature, light

Abiotic and Biotic Factors









Abiotic Factors







Biotic Factors







ECOSYSTEM

Discuss 2 ways biotic factors and 2

ways abiotic factors can affect the life

of a tree.

Habitat

 The place where an organism lives

 The address

 The habitat for a bull frog =

 The habitat of the giant anteater =

Niche

 What an organism does in an environment

 The occupation or the role of an organism

 Includes how an organism gets its food,

reproduces, avoids predators, etc.

 Determines an organisms habitat

 Example:

Wood peckers survive by finding insects in the

bark of a tree

Three Species of Warblers

and Their Niches







Cape May Warbler

Feeds at the tips of branches

near the top of the tree



Bay-Breasted Warbler

Feeds in the middle

part of the tree







Yellow-Rumped Warbler

Spruce tree Feeds in the lower part of the tree and

at the bases of the middle branches

Limiting Factors

 Each species is adapted to a specific set of

conditions

 Organisms thrive best in environments that

have specific conditions that meet their needs.

 Example:

Plants need sunlight.

Certain fish may prefer certain water

temperatures therefore will be found at certain

depths.

Populations

&

Communities

Population

 All the organisms of one species that live in

one place at a particular time

 Example:

Herd of deer

Flock of geese

Community

 All of the populations that interact with each

other in a particular place

 Living Organisms

 Example:

Bison, antelope, insects, grass

Wolf and Moose

Populations on

Isle Royale

60 2400









1990 1995



Moose Wolves





0 0

1955 1960 1965 1970 1975 1980 1985 1990 1995





Moose Wolf

Go to

Section:

Community Interactions

 Competition

 Predation



 Symbiosis



 Succession

Competition

 The main interaction between organisms

 May be for food, water, shelter, mate

 Results in natural selection= best fit survive

(evolution)

 • Types of Competition:

1. interspecific: competition between two different

species

Ex: lions and hyenas

2. intraspecific: competition between members of the

same species

Ex: a female lion competes with other lions for

food

Can you identify the types of

competition???

 Video - on CBS

 Number 2



 Number 3

Predation

 As a member of a population, you either “eat

or be eaten”

 Members of one population are the food

source for another population

 Predator:

The organism which is eating another

 Prey:

The organism which is being eaten

Define interspecific and

intraspecific forms of competition.

Give an example of each type.

Symbiosis

 When an organism has a close relationship

with another organism

 Each partner can help the other, harm the

other, or have no effect on the other partner

 Video clip of Symbiosis

Types of symbiosis

 1. parasitism:

A parasite lives on or in another organism for food or shelter

The host usually continues to live, but it is harmed

Ex: tapeworm in the human intestines

 2. commensalism:

One organism benefits while the other is unaffected

Ex. birds on the back of a buffalo

Fish attached to shark

 3. mutualism:

Both members of the relationship benefit

Ex: bacteria in our intestines

Bees and flowers

Succession

 The gradual replacement of one type of community

for another

 Occurs 2 ways:

1. Primary succession:

 Occurs in areas where there is no soil (bare rock,

hardened lava or ash)

 Lichens: first organism to appear; also called pioneer

species

2. Secondary succession:

 Occurs in areas where soils present (after a forest fire)

Lichens

Ecosystems

Basic Characteristics

of an Ecosystem:



1. Biotic Factors

2. Abiotic Factors

3. Energy Flow between organisms and their

environment

Freshwater Pond Ecosystem







Spoonbill

The shore is lined with grasses

Frogs lay eggs in the shallow that provide shelter and nesting

water near shore.The eggs places for birds and other

hatch in the water as tadpoles organisms.

and move to the land as adults.

Duck



Water

Frog lilies Mosquito Dragonfly

larvae Duckweed Phytoplankton



The roots of water lilies Snail

cling to the pond bottom, Diving Pickerel Plankton and the organisms that

while their leaves, on long beetle Fish share the pond feed on them live near the surface

flexible stems, float on the with turtles and other where there is enough sunlight for

surface. animals. Many of photosynthesis. Microscopic algae

them feed on insects are among the most important

at the water’s edge. producers.

The bottom of the pond is Trout

inhabited by decomposers and Hydra

other organisms that feed on

particles drifting down from the Snail Crayfish Benthic

surface. crustaceans

Energy Flow through Ecosystems

 Sunlight: main source of energy for life on

Earth

 Trophic levels:

Trophic= feeding

examples:

producers

consumers

 1st level

 Also called autotrophs

 Uses energy from the environment

(SUNLIGHT)

 plants

Primary Consumers

• Also called heterotrophs

• Organisms that feed on producers

• Deer, buffalo, mice, etc

Secondary Consumers



• Organisms that feed on primary

consumers

• Birds, fox, etc

Tertiary Consumers









• Organisms that feed on secondary

consumers

• Large hawk, cat, etc

Types of Consumers

 Herbivores:

Eats plants Ex. cows, deer, caterpillars

 Carnivores:

Meat eaters Ex: snakes, dogs, owls

 Omnivores:

Eats both plants and animals Ex. humans

 Detritivores:

Feeds on plant and animal remains and other dead matter

Ex. mites, earthworms, snails, crabs

 Decomposers:

Breaks down organic matter

Ex. bacteria, fungi

Food Chain

 Energy that is passed from one trophic level to

a trophic level that is higher

 Example:

Food Web

 Interconnected Food

Chains

Food Pyramid

 Shows trophic levels

 Producers on lowest level

 Also can show total mass of each organism in

the level

Ecological

Pyramids

Energy Pyramid Pyramid of Numbers

Shows the relative amount of Shows the relative

energy available at each trophic number of individual

level. Organisms use about 10 organisms at each

percent of this trophic level.

energy for

life processes.

The rest is lost

as heat.









Biomass Pyramid

Represents the amount of

living organic matter at each

trophic level. Typically, the

greatest biomass is at the

base of the pyramid.

DDT and Food Webs

 DDT was used as insecticide

 DDT does not break down in organisms and is

passed from one trophic level to the next

 Highest levels found at the top of the food

chain

 Known as biomagnifications

DDT in Eagles and Osprey



 Have highest levels of DDT

 Causes shells of eggs to be fragile

 Cause decrease of populations

 Why is a food web more

accurate than a food chain in

portraying the relationships

that exist among organisms in

an ecosystem?

Biome

•Based on yearly precipitation and temperature

(climate)

Heating of the Earth’s Surface and Some

Factors That Affect Climate

Greenhouse Effect Different Latitudes

90°N North Pole

Sunlight

66.5°N

Sunlight Arctic circle

Some heat

escapes Sunlight

into space

Tropic of Cancer

23.5°N

Equator

Greenhouse

gases trap Most direct sunlight 0°

some heat 66.5°S

Tropic of Capricorn



23.5°S

Sunlight

Atmosphere Arctic circle

Sunlight

Earth’s surface

90°S South Pole

The World’s Major

Land Biomes









Tropical rain forest Temperate grassland Temperate forest Tundra



Tropical dry forest Desert Northwestern Mountains and

coniferous forest ice caps

Tropical savanna Temperate woodland

and shrubland Boreal forest

(Taiga)

Biome Precipitatio Temperature Soil Diversity Trees Grasses

n

Tropical Rain high hot poor high dense sparse

Forest

Tropical Dry variable mild rich moderate medium medium

Forest

Tropical variable mild clay moderate sparse dense

Savanna

Desert low variable poor moderate sparse sparse

Temperate moderate summer hot rich moderate absent dense

Grassland

Temperate summer summer hot poor low medium medium

woodland and low, winter

Shrubland moderate

Temperate moderate summer rich high dense sparse

Forest moderate,

winter cold

Northwestern high summer mild, rocky, low dense sparse

Coniferous winter cold acidic

Forest

Boreal Forest moderate summer mild, poor, moderate dense sparse

winter cool acidic

Tundra low summer mild, poor low absent medium

winter cold

Project

• Food Web Biome Poster

The Recycling of Materials in

Ecosystems:

Carbon

 4 ways carbon is recycled in an ecosystem:

1. photosynthesis

2. respiration

3. decomposition (decay)

4. burning

The Carbon Cycle



CO2 in

Atmosphere









CO2 in Ocean

Oxygen Cycle

Nitrogen

 Nitrogen fixation:

 Special type of bacteria found on the roots of

legumes (peas, beans, peanuts, alfalfa, clover)

 Take free nitrogen from air and change it into

nitrates

 Nitrates used to make plant grow, plant

produces nutrients for bacteria = mutualism

The Nitrogen Cycle

N2 in Atmosphere









NO3-

and NO2-

NH3

The Water Cycle









Condensation

Precipitation









Evaporation Transpiration

Runoff







Seepage







Root

Uptake

Importance of

Biodiversity

Hardy-Weinberg Law

 5 conditions that must occur for a population not to

change:

1. no mutations

2. no immigration (entering) and no emigration

(leaving)

3. population must be large

4. individuals have the same chance of surviving

5. matings of individual organisms must be

random

Biodiversity

 The amount of variety in a community

 Also called species diversity



• Low biodiversity:

Few species of plants and animals

• High biodiversity:

Many species in a community

Importance of Biodiversity

1. ecosystem stability

2. medicinal purposes, possible cures for

diseases

 Main reason why biodiversity is decreasing:

Habitat destruction

 Ways humans destroy habitats:

Clearing land

building dams

highways, etc

Rain Forests



 70 -90% of the earth’s biodiversity will be lost

with destruction of rain forests

 Scientists are trying to identify and classify

many newly discovered organisms

 Fear that we are losing valuable medicines

People and the

Environment

Desertification

 Severe threat to our soil supply

 Loss due to drought or poor farming practices

 Ex.

Cattle grazing: Eat plants down to the roots;

plants can no longer hold nutrients. Land

becomes dry and bare.

Irrigation: water pumped from the ground

contains minerals (salt). Water evaporates,

minerals remain. Land is unsuitable for

agriculture.

Erosion

 Increased as humans cut forests and removes

plants

 Loose soil is washed away by rain

 Example:

Dust Bowl: Great Plains 1930’s

Farmers now grow crops in ways that

reduce soil erosion

Water pollution

 Raw sewage

 Thermal pollution

Air pollution

 Addition of gases and tiny solid particles

added to the air by human activities

Harmful Human Activities





 Burning of fossil fuels (coal, oil, natural gas)

 Industry

 Forest fires

Natural Occurrences

 Forest fires

 Dust storms

 Erupting volcanoes

Global

Air Pollution

Problems

Acid Rain

(Acid Precipitation)

 Harmful gases produced by burning coal, oil,

and gasoline

 Gases carried by winds for long distances

 Gases combine with water droplets, making

the rain acidic

 Damage has been done to many forests, lakes,

rivers, etc.

 Also damage to statues.

Global Warming

 Earth kept warm by carbon dioxide in the atmosphere

(greenhouse effect)

 Burning of fossil fuels releases excessive amounts of

carbon dioxide, which causes more heat to be

trapped.

 Also caused by burning of rain forests as land is

cleared.

 Average global temperatures have increased in the

past 100 years

 Causes climate changes which result in movements in

plant and animal species

Sunlight

The Greenhouse





Some heat

escapes

into space

Effect









Greenhouse

gases trap

some heat









Atmosphere







Earth’s surface

Ozone Depletion

 Caused by Chlorofluorocarbons

(CFCs)

 Found in air conditioners,

refrigerators, aerosol cans (hair

spray, deodorant, spray paint, etc)

 Ozone blocks UV radiation from

the sun.

 UV rays damages DNA in our

cells (skin cancer)

Montreal Protocol: 1987

 Agreement between many countries listing

steps needed to protect the ozone layer by

limiting or eliminating the use of ozone-

depleting chemicals by 1996.

Human Population Growth

 Most serious problem that affects all life on

Earth

 Increasing Agricultural revolution (better tools

and methods) and Industrial Revolution

 Advances in farming and medicine.

 1960 3 billion vs. 2000 6 billion (?)

 What is Earth’s carrying capacity for the

human population?

Human Population

Growth



Industrial

Revolution

begins

Agriculture

begins Bubonic

plague

Plowing

and

irrigation

International Conference on

Population and Development: 1994

 160 countries met

 Agreed that population growth can not

continue at current rate

 Population of any organism can not increase

forever.

 Polluted land, water, and air; lack of food and

space; and widespread disease will limit

population size

Direct Harvesting





• Destruction or removal of species from

their habitats

• Can lead to the extinction of species

• Ex:

Monkeys and parrots from the rain

forest

Baby harbor seals (for pelts)

Elephants (tusks to make jewelry)

Saving the

Biosphere

Dr. Seuss, The Lorax

 As an individual, make

a list of things that you

can do to protect our

environment.

Reduce: (use less)

 Use a mug or glass instead of paper cups for

drinks

 Make double sided photocopies

 Bring your own shopping bags to grocery store

Reuse

 Paper or plastic grocery bags

 Water jugs

Recycle

 Plastic

 Glass

 Metal

 Paper

 Examples:

1. Black Asphalt in NYC contains recycled glass

2. Building materials are made to look like wood

(actually plastic)

Renewable vs.

Nonrenewable

Renewable

 Can be replaced within a generation

 Enough is being made to replace what is being

used

 Ex:

Food

Wood

Oxygen

Nonrenewable:



 Can not be replaced

 Ex:

Coal, oil, natural gas

Gold, silver, iron, copper, aluminum

Sand, gravel, limestone

Things humans can do to

improve the biosphere







• Windmills, Endangered Species Act, The

Environmental Protection Agency, etc

HELP!



We are being invaded by aliens!

Foreign Species

 Plants or animals that are not native to an area

 Multiply very quickly because they do not

have any predators or competitors

 Often cause native species to decrease in

number

Zebra Mussels

(Russian native)

 When? 1980’s

 Where? St.Lawrence River

 Why? By accident, carried on boat

 What is the problem?

Attach themselves to surfaces and colonize

Clog piped, motors, bridges

Found in many waters of the eastern United

States

Mongoose



 When? 1877

 Where? Puerto Rico

 Why? Used to control rats that were damaging

sugarcane crops

 What is the problem?

Rats learned to avoid the mongoose. Mongoose

began to eat poultry, birds, and lizards. As lizard

population decreased, June beetle populations

increased. The also are pests of the sugarcane.

Purple Loosestrife

(European native)

 When? Early 1800’s

 Where? All of United States

 Why? Ornamental plant

 What is the problem?

It has invaded the wetlands of all 48 states.

 It has crowded out 44 native plants and endangered

the wildlife that depends on these plants.

 Approximately $45 million is spent a year trying to

control it.

The English Sparrow

 When? 1853

 Where? United States

 Why? Control canker worms (garden pests)

 What is the problem?

Ate crops instead.

 Displaces native birds and harasses others.

 Carries 29 diseases that affect both humans and

domestic animals.

 Canker worms are still garden pests!