EcologyUNIT 3

What is Ecology?

Ecologyu The study of the interactions

among living things, and between living things and their surroundings.

u Ecology is a science of relationships

u Ecology comes from the Greek word oikos, which means “house”.

Interdependence u The mutual reliance

between two or more groups.

u This relationship is key for the survival of the organism.

What Do We Mean By Environment?

The environment is made up of two factors:

1. Biotic factorsu All living organisms inhabiting

the Earth

u Examples:u Plants u Animals u Fungi u Bacteria

u Each plays a particular role in the ecosystem.

2. Abiotic factorsu Nonliving parts of the

environment

u Examples:u Temperature

u Soilu Light

u Moisture

The balance of these abiotic and biotic factors determines which living things can survive in a particular environment.

In the Caribbean Sea, scientist found that coral reefs located near salt water marshes have more fish than reefs farther out at sea level.

Key Biotic Factoru Mangrove Trees

u Provides food and shelter for newly hatched fish, protecting them from predators.

u After the fish mature, they swim to the reefs near the salt water marshes.

Key Abiotic Factors u Oxygen levels in the mud &

Salinity u Low levels of oxygen in the

mud affect the growth of mangrove trees.

u Changing levels of salinity, due to tidal changes also affect the growth of mangrove trees.

u No mangrove trees= no food and shelter for newly hatched fish.

Biodiversityu The assortment, or variety, of living

things in an ecosystem.

u An area with a high level of biodiversity, such as a rain forest, has a large assortment of different species living near one another.

u The amount of biodiversity depends on many factors.u For example, temperature.

Keystone Species u A species that plays a critical

role in maintaining the structure of an ecological community and whose impact on the community is greater than expected.

u Example: u The extinction of wolves at

Yellowstone led to the disappearance of beavers at Yellowstone.

Keystone u A keystone holds up an archway.

u Pennsylvania's nickname is "The Keystone State" u Pennsylvania has held a key

position in the economic, social, and political development of the United States.

u Keystone species holds together a dynamic ecosystem.

What are the Levels of

Organization?

Biosphere

Ecosystem

Community

Population

Organism

Biome

1. Biosphereu Life supporting portions of

Earth composed of air, land, fresh water, and salt water.

u The highest level of organization

2. Biome u Large group of ecosystems

that share the same climate and have similar types of communities

u These climates determines what types of plants live there.

u The types of plants determine the type of animal that live there.

3. Ecosystemu Populations in a

community and the abiotic factors with which they interact.

4. Communityu Several interacting

populations that inhabit a common environment and are interdependent.

u Example;u Elephant, Giraffe, and

Zebra

5. Populationu A group of organisms of one

species living in the same place at the same time that interbreed

u Produce fertile offspring

u Compete with each other for resources (food, mates, shelter, etc.)

u Herd of Caribou

6. Organism u Any unicellular or

multicellular form exhibiting all of the characteristics of life, an individual.

u The lowest level of organization

Nicheu Each species interacts with

its environment in a different way.

u All of the physical, chemical, and biological factors that a species needs to survive, stay healthy, and reproduce.

u You can think of a Nice as: How a species lives within its habitat.

Habitatu The place in which an

organism lives out its life.u You can think of a Habitat

as: Where the species lives.

Habitat vs. Niche

There Are Two Types of Niches:

Fundamentalu Area of NO

competition or limiting factors

Realizedu Area because of

competition or limiting factors

Types of Biomes

Polar Regions u The polar region is the

coldest biome on earth. u Dominated by ice caps. u Very few organisms live in

the polar regions. u Polar bears

u Seals u Walruses

u Whales

Taiga (Boreal Forest) u World’s largest biome. u Plants:

u Pinesu Sprucesu Firs u Shrubs u Mosses u Ferns

u Animals: u Deer u Bears u Foxesu Birds

Tundra u Tundra is a very cold biome.

u So cold the ground is always FROZEN!

u Small plants grow in the tundra

u Animals: u Reindeer u Grizzly Bear

u Brown Bearsu Artic Fox

u Birds

Temperate Forest u Temperatures are mild in winter and summer. u Humans often settle here

u Plants: u Flowering Trees

u Animals:u Deeru Wolves

u Birds

u Squirrels

u Rabbit

Temperate Grasslands u Known for having rich organic soil.

u Plants: u Different types of grasses

u Flowering plants

u Small trees

u Animals u American Bison

u Foxes

u Praire dogs

u Jackrabbits

Savanna u Type of grassland

u Plants:u Different types of grasses

u Trees

u Small flowering plants

u Animals u Gazelles

u Lions

u Cheetahs

u Elephants u Giraffes

u Zebras

u Rhinos

Tropical Rainforest u The tropical rainforest has extreme

biodiversity.

u Animals: u Monkeys

u Toucans

u Parrots

u Many different Reptiles

u Amphibians

u Insects

u Many different Plants!

Desertu The desert is a barren biome.

u Plants:u Cactus u Yucca

u Small Shrubs

u Animals:u Snakesu Lizards u Desert foxes

u Jackrabbits u Camels

Ecosystems

Freshwater Ecosystem u Include:

u Lakes u Ponds

u Some wetlands

u Plants and algae are important here. u Form the base of the food

chain.

u Provide oxygen and food for animals that live in Freshwater.

Marine Ecosystem u The largest ecosystem on Earth. u Have water with a higher salt

content than freshwater.

u Seawater is salty because salts and other minerals are deposited in it.

u There are a few different types of Marine Ecosystems:u Salt water marshes and

lagoons

u Coral reefs

All organisms must have a source of energy in order to survive. However not all organisms get their energy by eating other organisms...

Energy in Ecosystems

1. Producers

Autotrophs

2. Consumers

Heterotrophs

1. Produceru They get their own energy from

nonliving resources, meaning they make their own food.

u Producers are also called autotrophs. u “auto” means self

u “troph” means nourishment

u Bottom of the food chain

u All ecosystems depend on producers, because they provide the basis for ecosystem’s energy.

So, how do producers make

their own energy?

Photosynthesis u Most producers on Earth use

sunlight as their energy source.

u Photosynthesis is a process used by plants and other organisms to convert light energy into chemical energy that can later be released to fuel the organisms' activities (energy transformation).

u Photosynthesis in plants begins when energy from the Sun hits chloroplast and is absorbed.

Photosynthesis Reaction Organic

molecule

*Producers/Autotrophs

So, how do other organisms get their

energy?

2. Consumersu Organisms that get their

energy by eating other living or once living resources, such as plants or animals.

u Consumers are also called heterotrophs. u Hetero means different

u Consumers are categorized by what they eat.

Cellular Respiration Reaction

Organic molecule *Consumers/Heterotrophs

Law of Conservation of Mass

uStates that matter cannot be created or destroyed.

uIt can however, be converted into another form.

Consumers are Categorized by What

They Eat:

1. Herbivores

uObtain energy by eating only plants

For example: uAfrican Buffalo

eat plants.

2. Carnivores

uEat only animals.

For example: uLions eat

others animals.

3. Omnivores

uEat both plants and animals.

For example:uBears eat fish

and berries.

4. Decomposersu Breaks down dead

organic matter.

For example:u Earthworms consume

dead plants and decomposes them-reduces them to simpler forms of matter.

u “Nature’s recyclers”

Food Chainsu Is a sequence of how

energy transfers from one organism to another in a biological ecosystem.

u All food chains begin with a producers.

u A simple food chain could start with grass, which is eaten by rabbits. Then the rabbits are eaten by foxes.

How do food chains work?

Food Chainsu The first organism in a food chain is

a producer.

u A second organism will eat the producer.

u A third organism will feed on the second organism.

u A fourth organism will feed on the third organism.

first secondthird fourth

Food Chains u If a rabbit eats the grass,

and then a fox eats a rabbit….

u What do the arrows show?

u Flow of ENERGY!

Food Webu Is a natural interconnection

between food chains.

u Food webs are essential for the survival for organisms because placing your diet solely on one energy source can create issues if that food source drastically decreases.

Food Web u The arrows still show

energy transfer.

u A predator from one food chain may be linked to the prey of another food chain