Ecology

Ecology Ecology is the study of the interactions between

organisms and the living and nonliving components of their environment.

Can you think of any nonliving components?

All organisms depend on other living and nonliving things in its environment.

Organisms depend on the interactions with living and nonliving things. This is referred to as interdependence.

What kind of things in your surroundings are you interdependent upon?

Plants required for oxygen production

Water

Other animals for food.

Biotic and Abiotic Factors Biotic Factors: All of the living factors in an

ecosystem.

Abiotic Factors: All of the non-living factors in an ecosystem

Consequences of interdependence Any change in the environment can spread through

the network of interactions and affect organisms that appear far removed from the change.

How could an abundance of acorns affect the incidence of Lyme disease?

**Answer this question in your notebook!! Not sure what the answer should be? Google it!! **

Levels of Organization Ecologists recognize a hierarchy of organization in the

environment. Different Levels.

Each level has unique properties that result from interactions between its components, so a complete study of ecology would look at all levels.

For Biology we stop here

The biosphere The broadest, most inclusive level of organization

Earth and its atmosphere. All organisms found within the biosphere.

Ecosystem An ecosystem includes all of the organisms and the

nonliving environment found in a particular place.

Consider a pond ecosystem **answer this question in your notebook**

What kind of LIVING organisms are located in a pond ecosystem?

What kind of NON-LIVING organisms are located in a pond ecosystem?

Communities A community includes only species of organisms.

Living things!

All the interacting organisms living in an area.

Still very complex, and contains thousands of species.

Populations A population includes all members of a SINGLE

species that live in one place at one time.

A population of daisies in a meadow or a population of lemurs in the rainforest.

Organisms The individual organism living in a certain space!

YOU!!!

Energy Transfer All organisms need energy to carry out essential

functions, such as growth, movement, maintenance, and reproduction.

Sun-> Autotroph-> Consumers

Producers AUTOTROPHS, which include plants and some kinds

of bacteria manufacture their own food.

Capture ENERGY from the sun

Make their own food.

Measuring Productivity Some ecosystems capture more energy from the sun

and can produce more organic compounds for the ecosystem.

Which captures more energy desert biome or rainforest biome?

Ecologists refer to the organic material that has been produced in an ecosystem as BIOMASS.

Producers add biomass to an ecosystem.

Consumers All animals are HETEROTROPHS.

Heterotrophs are consumers.

These organisms are grouped into herbivores, omnivores, and carnivores.

Detritivores are consumers that feed on the “garbage” of an ecosystem.

What are some examples of detritivores?

Decomposers Many bacteria and fungi are detritivores that break

down complex molecules into simpler molecules.

These organisms are called decomposers.

Return nutrients to the soil.

Energy Flow When one organism eats another, molecules are

metabolized and energy is transferred.

What is the process called by which molecules are metabolized into energy?

Energy flows from producers to consumers.

Trophic Levels An organism’s trophic level indicates the organism’s

position in a sequence of energy transfer.

ALL PRODUCERS belong to the FIRST TROPHIC LEVEL.

CONSUMERS occupy the next levels.

Food Web The feeding relationships in an ecosystem are usually

too complex to be represented by a single food chain.

Many consumers eat more than one type of food.

The interrelated food chains in an ecosystem are called a FOOD WEB.

Food Web

10% Rule What is the problem with energy transfer in an ecosystem?

On average, 10 percent of the total energy consumed in one trophic level is incorporated into the organisms in the next!

Why is this?

When an organisms is killed and eaten, some of the molecules in the body will be in a form that the consumer cannot break down.

When a cougar eats a deer, it cannot use the energy stored in antlers, hooves, and hair.

Every time energy is transformed, such as during reactions of metabolism, some energy is lost as heat.

Organisms at the lowest trophic level are usually much more abundant than organisms at the highest level.

Why? ***Answer in your notebook!!***

Species Interactions Many species have specific types of interactions with

other species.

These interactions can be POSITIVE, NEGATIVE, or interactions that DO NOT matter to one organism.

Predators and Prey One species, predator, that eats all or part of an

individual of another species, called prey.

Predation is a powerful force within a community.

Why do we use the word community?

Predators are NOT just carnivores.

There is competition in a community. Life is difficult in nature.

Symbiosis A symbiosis is a close, long-term relationship between

two organisms.’

Are all interactions between organisms good? All bad?

Three examples of symbiotic relationships include

Parasitism

Mutualism

Commensalism

The Niche Species do not use or occupy all parts of their habitat

at once.

The specific ROLE, or way of life, of a species within its environment is its NICHE.

Niche Includes Conditions the animal can tolerate

Resources it uses, methods by which it obtains resources

Offspring it has

Its time of reproduction

All other interactions

Generalist GENERALTISTS are species with broad niches.

Use a variety of resources

Name a generalist species.

The Opossum- found all across the U.S. Feeds on almost anything.

Specialists Organisms that have a narrow niche.

Eat certain things, live in certain areas, and only in those areas.

Name a specialist organism.

The Koala Bear- eats only certain things (eucalyptus tree), and can only survive in areas where these trees are abundant.

Which type of species (specialist or generalist) would be most negatively affected by even minor changes in their ecosystem?

Succession The gradual, sequential re-growth of a community of

species in an area is called ecological succession.

You can see early stages of succession in vacant lots, along roads, and even in sidewalks or parking lots where plants are growing up through cracks.

There are two types of succession

Primary

Secondary

Primary Succession The development of a community in an area that has

not supported life previously, such as bare rock, a sand dune, or an island formed by a volcanic eruption.

Soil is not initially present.

Secondary Succession The sequential replacement of species that follows

disruption of an existing community.

What type of human activity could possibly lead to succession?

Secondary succession occurs where soil is already present.

Any new habitat, whether it is a pond left by heavy rain, a freshly plowed field, or newly exposed rock, is an invitation to many species that are adapted to the new conditions.

Pioneer species- species of organisms that dominate early in succession.

Tend to be small, and grow quickly

Reproduce quickly

Many weeds are pioneer species.

The traditional description of succession is that the community proceeds through a predictable series of STAGES until it reaches a stable end point, called a climax community.

Succession is regularly reset by disturbances.

Climax community may never be reached because of constant disturbances

Ecosystem Recycling As energy and matter flow through an ecosystem,

matter must be recycled and reused.

Substances such as water, carbon, and nitrogen pass between the living and nonliving world through biogeochemical cycles.

The Water Cycle The availability of water is one of the key factors that

regulate the productivity of terrestrial ecosystems.

Bodies of water contain most of the water on earth.

The atmosphere also contains water—in the form of water vapor.

Some water is found below ground in the form of ground water.

Evaporation/Transpiration/Precipitation

Evaporation adds water as vapor to the atmosphere.

Heat causes water to evaporate from bodies of water, from the soil, and from living things (plants)

Animals participate in the water cycle.

Why do animals require water?

Required for cellular respiration! Can’t break down food to produce energy without water!

Water leaves the atmosphere through precipitation (rain, snow)

The amount of water the atmosphere can hold depends on abiotic factors such as temperature and pressure.

The Carbon Cycle Photosynthesis and cell respiration form the basis of

the carbon cycle.

In photosynthesis, plants use carbon dioxide to make carbohydrates.

Animals release carbon dioxide during respiration.

When fossil fuels are burned carbon dioxide is released into the atmosphere.

The Nitrogen Cycle All organisms need nitrogen to make proteins and nucleic

acids. The pathway that nitrogen follows in an ecosystem is called

the nitrogen cycle. Nitrogen gas (N-N) makes up about 78 percent of the

atmosphere But not readily available in the gaseous form

Most plants can use nitrogen only in the form of nitrate. Process of converting nitrogen gas to nitrate is known as

nitrogen fixation Animals obtain nitrogen by eating plants and other

organisms and then digesting the protein and nucleic acids.

The oxpecker bird usually feeds on insects on a rhinoceros's back. Occasionally this bird picks scabs off the rhioceros’s back and drinks blood from the wounds. What type

of relationship is demonstrated? A. Mutualism

B. Commensalism

C. Parastism

D. Mutualism and Parasitism

Collectively, all of the abiotic and biotic factors in an area are best described by the following:

A. Population

B. Community

C. Ecosystem

D. Organelle

E. Molecule

Consider the following simple food chain: Algae -> Mosquito larvae->Dragonfly larvae->Perch->Pike According to the diagram, which is a tertiary consumer?

A. Algae

B. Pike

C. Mosquito Larvae

D. Dragonfly Larvae

E. Perch

Carbon dioxide returns to a community during the _______ cycle, and exits a community during the _______ cycle

A. Krebs, Calvin

B. Calvin, Krebs

C. Water, Nitrogen

D. Nitrogen, Krebs

E. Krebs, Nitrogen

If there are 10000 J of energy available at the primary consumer trophic level, how many Joules of enegy are available at the tertiary consumer trophic level?

A. 10000

B. 1000

C. 100

D. 10

A. Climax community

B. Primary succession

C. Secondary succession

D. Terminal community

When the settlers arrived in New England, many forests were turned into fields. Eventually, some fields were abandoned and then grew back into forests. This is best described as