Click on a lesson name to select.

Chapter 2 Principles of Ecology

Section 1: Organisms and Their Relationships

Section 2: Flow of Energy in an Ecosystem

Section 3: Cycling of Matter

Ecology Scientific discipline in which the

relationships among living organisms and their environment.

2.1 Organisms and Their Relationships Chapter 2 Principles of Ecology

Ecologists observe, experiment, and model using a variety of tools and methods.

The Biosphere A thin layer around Earth

Principles of Ecology

Extends several kilometers above the Earth’s surface

Extends several kilometers below the ocean’s surface

2.1 Organisms and Their Relationships Chapter 2

The Biosphere

Principles of Ecology

2.1 Organisms and Their Relationships Chapter 2

Biotic Factors

Principles of Ecology

Living factors in an organism’s environment Ex: Animals, plants

Abiotic Factors Nonliving factors in an organism’s

environment Ex: Sunlight, temperature

2.1 Organisms and Their Relationships Chapter 2

Levels of Organization

Principles of Ecology

Levels increase in complexity as the numbers and interactions between organisms increase.

organism population biological community ecosystem biome biosphere

2.1 Organisms and Their Relationships Chapter 2

The lowest level of organization is the individual organism .

Principles of Ecology

Organisms of a single species that share the same geographic location at the same time make up a population.

A biological community is a group of interacting populations that occupy the same geographic area at the same time.

2.1 Organisms and Their Relationships Chapter 2

An ecosystem is a biological community and all of the abiotic factors that affect it.

Principles of Ecology

A biome is a large group of ecosystems that share the same climate and have similar types of communities.

2.1 Organisms and Their Relationships Chapter 2

Ecosystem Interactions

Principles of Ecology

A habitat is an area where an organism lives.

A niche is the role or position that an organism has in its environment.

2.1 Organisms and Their Relationships Chapter 2

• While many species may share a habitat, this is not true of a niche. Each plant and animal species is a member of a community. The niche describes the species' role or function within this community.

• For example, the red fox's habitat might include forest edges, meadows and the bank of a river. The niche of the red fox is that of a predator which feeds on the small mammals, amphibians, insects, and fruit found in this habitat. Red foxes are active at night. They provides blood for blackflies and mosquitoes, and are host to numerous diseases. The scraps, or carrion, left behind after a fox's meal provide food for many small scavengers and decomposers. This then is the ecological niche of the red fox. Only the red fox occupies this niche in the meadow-forest edge communities. In other plant communities different species of animal may occupy a similar niche to that of the red fox. For example, in the grassland communities of western Canada and the United States, the coyote occupies a similar niche (to that of the red fox.)

Carefully observe the picture below and list all the abiotic factors and

biotic factors you see.

Community Interactions

Principles of Ecology

Competition Occurs when more than one organism

uses a resource at the same time Predation

Many species get their food by eating other organisms.

2.1 Organisms and Their Relationships Chapter 2

Symbiotic Relationships

Principles of Ecology

The close relationship that exists when two or more species live together

Mutualism: both benefit Commensalism: one benefits, the other is

not helped or harmed. Parasitism: one benefits and the other is

harmed.

2.1 Organisms and Their Relationships Chapter 2

Mutualism

Commensalism

Parasitism

Energy in an Ecosystem

Autotrophs AKA Producer

2.2 Flow of Energy in an Ecosystem

Principles of Ecology

Organism that collects energy from sunlight or inorganic substances to produce food

Heterotrophs AKA Consumer

Organism that gets it energy requirements byconsuming other organisms

Chapter 2

Heterotrophs, AKA Consumers

Types:Herbivores: plant eatersCarnivores: meat eatersOmnivores: plant and meat eatersDetritivores: eat plant and animal remains

ecosystem, and return nutrients to the soil, air, and water to be

reused.

Decomposers get energy from fragments of dead matter in an

Principles of Ecology

Fungus

2.2 Flow of Energy in an EcosystemChapter 2

Principles of Ecology

Models of Energy Flow

Food chains and food webs model the energy flow through an ecosystem.

Each step in a food chain or food web is called a trophic level.

2.2 Flow of Energy in an EcosystemChapter 2

What are trophic levels?• Trophic levels represent each step in a food chain

– 1st level = producers– 2nd level = herbivores– 3rd level and up = carnivores and omnivores

Principles of Ecology

Food Chains A food chain is a

simple model that shows how energy flows through an ecosystem from one organism to another.

2.2 Flow of Energy in an EcosystemChapter 2

Principles of Ecology

Food Webs

A food web is a model representing the many interconnected food chains and pathways in which energy flows through a group of organisms.

2.2 Flow of Energy in an EcosystemChapter 2

Principles of Ecology

Ecological Pyramids A diagram that can show the amounts of

energy, biomass, or numbers of organisms at each trophic level

2.2 Flow of Energy in an EcosystemChapter 2

Only about 10 percent of the total energy gets passed from one trophic level to the next.

Cycles in the Biosphere

2.3 Cycling of Matter

Principles of Ecology

Energy is transformed into usable forms to support the functions of an ecosystem.

The cycling of nutrients in the biosphere involves both matter in living organisms and physical processes found in the environment such as weathering.

Chapter 2

The Water Cycle

Principles of Ecology

2.3 Cycling of MatterChapter 2

Principles of Ecology

The Carbon and Oxygen Cycles

2.3 Cycling of MatterChapter 2

Principles of Ecology

The Nitrogen Cycle

The capture and conversion of nitrogen into a form that is useable by plants is called nitrogen fixation.

2.3 Cycling of MatterChapter 2

Principles of Ecology

Nitrogen is returned to the soil in several ways:

Animals urinate. Organisms die. Organisms convert ammonia into

nitrogen compounds. Denitrification

2.3 Cycling of MatterChapter 2

Principles of Ecology

The Phosphorus Cycle

2.3 Cycling of MatterChapter 2

Making your own “tri-fold” Cycling of Matter Study Guide

You must have the following words (and define them!!) in each of your cycles. You must also come up with your own creative

environment/scenario (NOT found in your textbook).

Water Cycle•Transpiration•Precipitation•Evaporation•Percolation•Run off•Solar energy•Water

Nitrogen Cycle•Atmospheric nitrogen•Nitrogen fixing bacteria & plant roots•Denitrifying bacteria•Nitrifying bacteria•Excretion/Animal Waste•Animal•Plants

Carbon-Oxygen Cycle•Balanced Equation: Photosynthesis & Cell Respiration•Respiration•CO2 (where)•O2 (where)•Diffusion•Combustion•Plants & Animals•Decomposition•Fossil Fuels

Phosphorous Cycle•Phosphates•Sediments•Weathering of rocks/Erosion•Decomposers•Animal waste/decay•Plants•Animals