Environmental Science: Chapter 18 The study of the interactions between organisms and their environment.

ecology

community

biotic ecosystem population ecosystem ecology abiotic community biotic biotic ecosystem habitat abiotic population ecology

community

niche biosphere ecology

Section 1 Everything is Connected

Biotic factors:

• All the organisms that live together and interact with one another.

Abiotic factors:

• All of the physical factors (non-living things) that affect organisms • Examples: water, air, soil , light, temperature, wind, humidity, waves, currents, gravity, etc.

Organism-

• An individual form of life • Anything that can carry out life processes independently

Population-

• A group of individuals of the same species that live together in the same area at the same time.

Community-

All of the populations of different species that live and interact in an area.

Ex. Fawn Lake:

• An ecosystem is made up of a community of organisms and it includes its ABIOTIC environment • Example: the ocean, tropical rain forest, salt marsh, river, etc.

Biosphere The part of the earth where life exists.

5 Levels of Environmental

biosphere

Organization:

ecosystem community organism population

Cape Cod

Salt Marsh Ecosystem:

Section 2

LIVING THINGS NEED

ENERGY!

99.9% of living things get their energy from where?

Black smokers ….feed clams and tube from worms … energy here comes sulfur chemicals inside the earth

These exist on average at depths of 6,890 feet below the surface of the oceans !

Submersible : Alvin

All organisms are either:

•

A producer

•

A consumer or

•

A decomposer

What’s a Producer ?

• Organisms that use

sunlight

to make food… directly Ex. plants, algae, some bacteria

Producers do this by the process of…

A Consumer

• Is an organism that eats other organisms – They eat producers (like plants) or – They eat other animals

What are the four types of Consumers?

Decomposers • Organisms that get energy by breaking down the remains of dead organisms • Ex. Bacteria, Fungi • Known as “nature’s recyclers”

What are the 2 main decomposers?

•Bacteria !

•Fungi !

This chain of energy transferring from one species to another can continue several more times, but it eventually ends. It ends with the dead animals that are broken down and used as food or nutrition by bacteria and fungi . As these organisms, referred to as decomposers, feed from the dead animals, they break down the complex organic compounds into simple nutrients. Decomposers play a very important role in this world because they take care of breaking down (cleaning) many dead material. There are more than 100,000 different types of decomposer organisms! These simpler nutrients are returned to the soil and can be used again by the plants. The energy transformation chain starts all over again.

Cycle of Life… Names and word definitions

What’s the difference between a Food Chain and a Food Web?

•Food Chain-shows how energy in food molecules flows from one organism to the next •Food Web-a complex diagram showing many energy pathways in a real ecosystem

In a food chain or Food Web:

• The arrow shows the direction of energy movement.

• Which is correct?

• A) Worm Robin • B) Robin

Worm

What two things does an Energy Pyramid show?

•

Number of organisms

•

Amount of energy available at each level:

Wolves

Canus lupis • Used to be common throughout the country • They are predators that prey on large animals such as elk, deer, moose, buffalo, bison • Considered at the top of the Energy Pyramid in their ecosystem • Almost wiped out as the wilderness was settled • Results of their disappearance to the ecosystem?

Complete change of the food web:

Cervus americanus

• Elk populations

increased

… – Overgrazing (by elk) – Grasses became wiped out – Populations of animals dependant on grasses were wiped out (hares, prairie dogs, skunks, chipmunks, and other small mammals) • Wipe-out of animals like foxes that eat the small mammals

In 1995

• Wolves were reintroduced to Yellowstone National Park:

•

How’s a habitat different from a niche?

Habitat-

•

Niche-

•

(where it lives)

•

(its

role

within the ecosystem)

Habitat?

Spider Niche?

• Habitat?

Dog

• Niche?

• Habitat?

Maple Tree

• Niche?

Section 3…

Types of Interactions

…

Interactions in the environment…

• Limiting Factors-things that slow the growth of a population such as

food, water, or space, sunlight

• Carrying Capacity

Carrying Capacity

• The largest population that an

environment can support over a long period of time.

Carrying Capacity

Example in Bedford?…

The deer population !

Oh Deer Game !

Interactions with Other

Organisms: • There are 4 main ways that species and individuals affect each other:

– Predators and Prey – Competition – Symbiosis – Coevolution

Predator-Prey • One organism eats another:

predator prey

Adaptations of predators and prey:

• Characteristics that improve an organism’s ability to survive and reproduce • Ex. Goldenrod spider: – Ambush their prey – Camouflage their bodies

Prey adaptations:

• Warning coloration: • Schooling in fish • Herding in antelopes, zebras • Camouflage • Chemical defenses

•

Two cannibals are eating a clown. One says to the other: "Does this taste funny to you?"

Competition

• When 2 or more individuals or populations try to use the

same limited resource

such as:

• Food • Water • Shelter • Space • Sunlight

• Can occur within a population as well as between populations of different species

Symbiosis:

• Mutualism • Commensalism • Parasitism

Mutualism

Coral polyps • Both organisms benefit: bacteria Lives inside Contain living algae human intestines

clownfish living in anemones

Commensalism

•One benefits while one is unaffected:

Remora fish live on the underside of sharks

Epiphytes

• Organisms (usually plants) that grow

on

other plants and do not harm them.

Examples of epiphytes…

•Air plants

Spanish moss

Lichens

• moss

Parasitism Fleas, ticks, worms, leeches

• One benefits while the other is

harmed:

• The animal the parasite lives

on or in is called the HOST

parasites

Tobacco Hornworm with parasitizing wasp eggs:

No parasites parasites

Coevolution

• The “long-term change”

that takes place in two species because of their close interactions with each other.

Example on next slide…

Flowers coevolved with pollinators…

• •

Hummingbirds and ornithophilous flowers

Hummingbirds and ornithophilous flowers have evolved to form a mutualistic relationship. It is prevalent in the bird’s biology as well as in the flower’s. Hummingbird flowers have nectar chemistry associated with the bird’s diet. Their color and morphology also coincide with the bird’s vision and morphology. The blooming times of these ornithophilous flowers have also been found to coincide with hummingbirds' breeding seasons.

•

Garter snake and Rough-skinned newt

• Coevolution can occur between predator and prey species as in the case of the Rough-skinned Newt (

Taricha granulosa

) and the common garter snake (

Thamnophis sirtalis

). In this case, the newts produce a potent nerve toxin that concentrates in their skin. Garter snakes have evolved resistance to this toxin through a set of genetic mutations , and prey upon the newts. The relationship between these animals has resulted in an evolutionary arms race that has driven toxin levels in the newt to extreme levels.

•

Acacia ant and Swollen thorn acacia tree

• The ant provides protection for the tree against preying insects and other plants competing for sunlight, and the tree provides nourishment and shelter for the ant and the ants' larvae.

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