Chapter 2: Principles of Ecology

WoodElizabethton HighGlencoe Biology

Chapter OverviewBig idea: Energy is required to cycle

materials through living and non-living systems.

Section 1: Organisms and Their Relationships

Section 2: Flow of Energy in an Ecosystem

Section 3: Cycling of Matter

Section 1: Organisms and Their RelationshipsI. Ecology (32)II. The Biosphere (34)III. Abiotic vs. Biotic Factors (35)IV. Levels of Organization (36)V. Climate vs. WeatherVI. Ecosystem Interactions (38)VII. Community Interactions (38)

I. Ecology p.32A. Ecology is the study of the

relationship between an organism, and the environment that the organism lives in.

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

II. The Biosphere p.34A. The thin layer of

atmosphere around the Earth where all almost all living organisms are found.

i. Bio~ Life Sphere~ GlobeB. Extends several kilometers

above and below the Earth’s surface

III. Biotic vs. Abiotic FactorsA. Biotic

i. Bio~ Living -tic~ Factorii. Living factors in an organism’s

environmenta) Anything that is currently or once living.

B. Abiotici. A~ not Bio~Living Tic~factorii. Nonliving factors in an organism’s

environmenta) Sunlight, temperature, rocks, and

rainfall.

IV. Levels of OrganizationA. Levels increase in complexity as

the numbers and interactions between organisms increase.

B. This list is from smallest to largest.

i. Organism- The lowest level of organization is the individual organism itself

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

Ex) School of Fish

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

Ex) Biotic factorsof a coral reef

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

Ex) Coral reef with all of the abiotic factors.

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

V. Climate vs. WeatherA. Weather- what it is currently

like outside. i. Ex) what clothes you are

wearing today.

B. Climate- the average weather over a period of time.

i. The type of clothes you have in your closet

VI. Ecosystem InteractionsA. A habitat is an area where

an organism lives.

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

VII. Community Interactions A. Competition

i. Occurs when more than one organism uses a resource at the same time

B. Predationi. Many species get their food

by eating other organisms.

C. Symbiotic Relationshipsi. The close relationship that

exists when two or more species live together

D. Three different types

E. Mutualismi. When both organisms

benefit

F. Commensalismi. One organism benefits and the other organism is neither helped nor harmed.

G. Parasitismi. One organism benefits at

the expense of another. a) Ex) mosquito

2.2: Flow of Energy in an Ecosystem

I. Autotrophs (41)II. Types of Heterotrophs (41)III. Models of Energy Flow (42)

Autotrophs p.41A. Organism that collects

energy from sunlight or inorganic substances to produce food

Ex) Sunflowers and some bacteria

Types of Heterotrophs p.41A. Heterotoph- an organism

that gets its energy requirement by consuming another organism.

B. There are 4 types of heterotrophs.

i. Herbivorea) A herbivore is an organism

that has adapted to only eat plant-based foods.

Ex) Hippopotamus

ii. Carnivorea) A carnivore is a heterotroph

that preys on other heterotrophs.

Ex) Liger

iii. Omnivorea) An omnivore is an organism

that has adapted to eat both plants and animals.

Ex) Humans

iv. Detritivoresa) A detritivore eats fragments

of dead matter in an ecosystem.

Ex) Earthworm

III. Models of Energy Flow p.42

A. Ecologists use food chains and food webs to model the energy flow through an ecosystem.

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

C. Food Chainsi. A food chain

is a simple model that shows how energy flows through an ecosystem.

D. Food Webs• A food web is

a model representing the many interconnected food chains within an ecosystem.

E. Ecological Pyramidsi. An ecological pyramid is a

diagram that can show the relative amounts of energy, biomass or food chains.

ii. Each trophic level only has 10% of the energy of the level below available to it.

2.3 Cycling of MatterI. Water Cycle (46)II. Carbon/Oxygen Cycle (47)III. Nitrogen Cycle (48)IV. Phosphorus Cycle (49)

I. Water Cycle p. 46

A. Approximately 90 percent of water vapor evaporates from oceans, lakes, and rivers; 10 percent evaporates from the surface of plants through a process called transpiration.

B. Freshwater constitutes only about 3 percent of all water on Earth.

II. Carbon/Oxygen Cycle p.47

A. Long-term Cyclei. Organic matter converted

to coal, oil, or gas deposits (carbon)

ii. Calcium carbonate (carbon and oxygen)

B. Short-term Cyclei. Burning fossil fuels (carbon)ii. Photosynthesis and Cellular

Respiration

III. Nitrogen Cycle p. 48A. The capture

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

B. Nitrogen enters the food web when plants absorb nitrogen compounds from soil. This makes the plants grow at a faster rate.

C. Consumers get nitrogen by eating plants or animals that contain nitrogen.

D. Nitrogen is returned to the soil in many ways.

i. Animals urinateii. Organisms dieiii. Organisms convert

ammonia into nitrogen compounds.

iv. Denitrification

IV. Phosphorus Cycle p. 49

A. Long-term Cyclei. Erosion of rocks slowly

adds phosphorus to the cycle.

B. Short-term Cyclei. Phosphorus is cycled from

the soil to producers and then from the producers to consumers.