3.1 What Is Ecology?

Chapter 3

3.1 – What is Ecology?

Interactions and Interdependence

J Ecology – the study of interactions among organisms and their environment

J Oikos (ec) – Greek word meaning house

J Ology – means study of

Levels of Organization

J The levels of organization that ecologists study include:

J Individuals

J Species – group of similar organisms that can breed and produce fertile offspring

J Populations – group of individuals of the same species that live in the same area and interbreed

J Communities – different populations that live together in a defined area

J Ecosystem – The interaction of all the organisms and the environment in a given area

J Biome – a group of ecosystems that have the same climate

J Biosphere – part of Earth in which life exists including land, water and atmosphere

J It extends about 8km above the Earth’s surface to about 11km below

J If you could shrink earth to the size of an apple, the biosphere would be thinner than the apple’s peel

Biotic and Abiotic Factors

J Biotic Factors – all the living organisms in an ecosystem

J Example: tree, bird, bacteria, fungi

J Abiotic Factors – nonliving factors in an ecosystems

J Example: temperature, precipitation, wind, soil, sunlight, humidity

J Habitat – area where an organism lives

J Includes both biotic and abiotic factors

J Niche – the role and position a species has in its environment

J No two species can share the same niche in the same habitat

3.2 – Energy Flow

J Sunlight is the main energy source for life

J Autotrophs

J Make their own energy

J Convert sun energy into chemical energy

J Also called a producer

J Plants are the main autotrophs on land

J Algae are the main autotrophs in water

J Some autotrophs can produce food in the absence of light

J Chemoautotrophs – organisms use chemical energy to produce carbohydrates

J Performed by several types of bacteria

J Live in…

J Volcanic vents

J Deep ocean

J Hot springs

J Marshes

J Heterotrophs

J Get energy from other organisms

J Unable to make its own energy

J Also called consumers

J Types of Heterotrophs

J Herbivores

J Eats only plants

J Example: cows, deer, rabbits, bees, elephants, squirrels

J Carnivores

J Eats only animals

J Example: snakes, dogs, lions, crocodiles

J Omnivores

J Eats plants and animals

J Example: humans, bears, crows

J Detrivores

J Eat decomposing bits of organic matter

J Example: mites, earthworms, snails, crabs

J Decomposers

J Break down organic matter

J Example: bacteria and fungi

J Scavenger

J Ingest nonliving plants and animals

J Example: vulture, termite, beetle

Feeding Relationships

J Food Chain – a straight line series of steps by which energy is stored and passed on to higher trophic levels

J Food Web – a network of crossing interlinked food chains that shows all the possible feeding relationships at each trophic level

J Energy is passed through no more than four or five trophic levels

J Trophic Levels – step in a food chain or food wed

J Plants and other producers are 1st trophic level

J Consumers make up the 2nd, 3rd, or higher trophic levels

J Each consumer depends on the trophic level below it for energy

J Energy is transferred from one trophic level to another and is never 100%

J At each trophic level only 10% of the energy taken in by the organism is stored. The rest is used up during metabolism to process the energy

Community Interactions

J Competition – occurs when organisms of the same or different species attempt to use the same resources

J Predator – eat other animals

J Prey – the animal a predator eats

J Symbiosis – relationship in which two species live closely together

J Three Types of Symbiosis

1. Mutualism

J Both species benefit from the relationship

J Example: plants and bacteria on roots

Shark and fish

2. Commensalism

J One organism benefits and the other is neither helped nor harmed

J Example: tree and bird nest

3. Parasitism

J One organism lives on or inside another organism and harms it

J Example: tick, ringworm

Ecological Pyramids

J Ecological Pyramid – a diagram that shows the relative amounts of energy or matter contained within each trophic level in a food chain or food web

J Example: Ecological Pyramids

3-3 Cycles of Matter

J Biogeochemical Cycles – process in which elements, chemical, and other forms of matter are passed from one organism to another and from one part of the biosphere to another

The Water Cycle

J Evaporation – process by which water changes from a liquid to a gas

J Transpiration – loss of water from plants by the process of evaporation

J Condensation – water vapor changes to a liquid

J Precipitation – water returns to the earth (rain, snow, hail)

The Carbon Cycle

J Carbon is released into the atmosphere by…

J Respiration

J Burning fossil fuels

J Volcanic activity

J Burning trees

J Carbon is taken out of the atmosphere by…

J Photosynthesis performed by plants

J Carbon is released into the ground by…

J Decomposition of plants and animals

J Carbon is taken out of the ground by…

J Mining

J Roots of plants

Nitrogen Cycle

J Gaseous nitrogen (N2)makes up 80% of the atmosphere

J Nitrogen Fixation

J Bacteria convert N2 to ammonia (NH3)

J This dissolves forming ammonium (NH4)

J Ammonification

J Bacteria degrade nitrogenous wastes and remains of organisms

J Convert NH3 to NH4+

J Nitrification

J Bacteria convert NH4 to nitrite (NO2) to nitrate (NO3)

J Denitrification

J Bacteria convert nitrate or nitrite (NO3, NO2) to N2

J N2 is released back into the atmosphere

J Humans are harming the nitrogen cycle by:

J Deforestation

J Conversion of grasslands for agriculture

J Sewage enters waterways

J Fossil fuel burning

J Vehicles having combustion engines releases NO2

4-2 What Shapes an Ecosystem?

Ecological Succession

J Succession – changes that occurs in a community over time

J Pioneer Species – first species to populate the area

J Climax Community – a stable mature community that undergoes little or no change in species

J Two Types of Succession

1. Primary Succession

J Succession that occurs on surfaces where no soil exists

J Example: rock surfaces formed after volcanoes erupt

2. Secondary Succession

J Succession following a disturbance that destroys a community without destroying the soil

J Because soil already exists, secondary succession usually takes less time than primary succession

J Example: fires, floods, farming, construction, hurricanes, tornadoes

Chapter 3

3.1 – What is Ecology?

Interactions and Interdependence

J Ecology –

J Oikos (ec) – Greek word meaning ____________

J Ology – means __________ _____

Levels of Organization

J The levels of organization that ecologists study include:

J Individuals

J Species –

J Populations –

J Communities –

J Ecosystem –

J Biome –

J Biosphere –

J It extends about _____km above the Earth’s surface to about _____km below

J If you could shrink earth to the size of an apple, the biosphere would be thinner than the apple’s peel

Biotic and Abiotic Factors

J Biotic Factors –

J Example:

J Abiotic Factors –

J Example:

J Habitat –

J Includes both biotic and abiotic factors

J Niche –

J No two species can share the same niche in the same habitat

3.2 – Energy Flow

J _______________ is the main energy source for life

J Autotrophs

J Convert __________ energy into ____________ energy

J Also called a _______________

J ____________ are the main autotrophs on land

J ____________ are the main autotrophs in water

J Some autotrophs can produce food in the absence of light

J Chemoautotrophs –

J Performed by several types of bacteria

J Live in…

J Heterotrophs

J Also called _______________

J Types of Heterotrophs

J Herbivores

J Example:

J Carnivores

J Example:

J Omnivores

J Example:

J Detrivores

J Example:

J Decomposers

J Example:

J Scavenger

J Example:

Feeding Relationships

J Food Chain –

J Food Web –

J Energy is passed through no more than ________ or ________ trophic levels

J Trophic Level –

J _______________and other producers are 1st trophic level

J _______________make up the second, third, or higher trophic levels

J Each consumer depends on the trophic level below it for energy

J Energy is transferred from one trophic level to another and is never ________

J At each trophic level only ________ of the energy taken in by the organism is stored. The rest is used up during _______________ to process the energy.

Community Interactions

J Competition –

J Predator –

J Prey –

J Symbiosis –

J Three Types of Symbiosis

1. Mutualism

J Example:

2. Commensalism

J Example:

3. Parasitism

J Example:

Ecological Pyramids

J Ecological Pyramid –

3-3 Cycles of Matter

J Biogeochemical Cycles –

The Water Cycle

J Evaporation –

J Transpiration –

J Condensation –

J Precipitation –

The Carbon Cycle

J Carbon is released into the atmosphere by …

J Carbon is taken out of the atmosphere by …

J Carbon is released into the ground by …

J Carbon is taken out the ground by …

Nitrogen Cycle

J Gaseous nitrogen (N2) makes up ________% of the atmosphere

J Nitrogen Fixation

J This dissolves forming _______________ ________

J Ammonification

J ____________ degrade nitrogenous wastes and remains of organisms

J Convert _______ to _______

J Nitrification

J Bacteria convert ________ to ____________ (NO2) to ____________ (NO3)

J Denitrification

J Bacteria convert ____________ or ____________ (NO2 and NO3) to N2

J N2 is released back into the ______________

J Humans are harming the nitrogen cycle by:

Ecological Succession

J Succession –

J Pioneer Species –

J Climax Community –

J Two Types of Succession

1. Primary Succession

J Example:

2. Secondary Succession

J Succession following a disturbance that

J Because soil already exists, secondary succession usually takes ________ time than primary succession

J Example: