ECOLOGY is the scientific study of interactions among organisms with each other and with the environment.

The German biologist Ernst Haeckel came up with the term “ecology”, as he viewed nature as a house with its own economy.

The largest of nature’s “houses” is the biosphere. The biosphere refers to the

biological component of Earth’s systems. In other words, all life found on the planet.

InterdependenceOrganisms and their environment are interdependent. Every organism relies on other organisms to survive.

For example, the snail could not survive without plants and algae to eat, and the plants and algae would not grow without bacteria that help

recycle nutrients.

The interdependence among organisms is a huge dynamic of the biosphere. Picture a complex web of interdependence. Everything is dependent on something else!

The study of ecology ranges from the study of an individual organism to a study of the entire planet as follows:

✴ Individual✴ Population✴ Community✴ Ecosystem✴ Biome✴ Biosphere

Levels of Organization

Species- a group of individuals similar to one another that can breed and create fertile offspring.

Population- A group of organisms of one species that interbreed and live together within a defined area.

Examples of populations-A herd of sheepA flock of geeseA colony of antsA culture of bacteriaA sleuth of bearsA brood of chickensA pack of dogs

Communities are groups of populations comprised of many species that live together in a defined area.

An ecosystem is a combination of the communities and the physical (nonliving) environment.

An ecosystem is all the living and nonliving factors in a particular place. An ecosystem can be small or large.

Examples:

Rotting LogKoi PondLakeClump of DirtA fieldAn old maple treeBogMarsh

Biome - large area that has a particular climate, and particular species of plants and animals that live there (tundra, rainforest, desert).

A biome is a large group of many ecosystems.

Biodiversity- the variety of organisms, the organisms genetic differences, and the ecosystems in which they occur.

• Ecological diversity- refers to the different ecosystems in a region

• Species diversity- refers to the different species within certain ecosystems

Tropical rainforests have the highest biodiversity of all the

biomes.

Abiotic factors- nonliving factors that can affect an ecosystem (soil, pollution, natural disasters, climate).

Factors that Affect Ecosystems

Biotic factors- Living factors that can affect an ecosystem (plants and animals).

Factors that Affect EcosystemsBiotic AND abiotic factors determine the survival and growth of individual organisms and ultimately the ecosystem.

Biotic factors that affect bullfrogs would be availability of food and other species that compete with the bullfrog for food or space.

Abiotic factors that affect bullfrogs would be water

availability and temperature.

A habitat is a place where a particular population lives (anthills, squirrel nests, beaver dams, marshes, etc.)

Habitats include both abiotic and biotic factors.

Though it may not appear this way, ecosystems are constantly changing.

Succession- A regular progression of species of replacement over time-- ecosystems evolving

Succession is typically slow, but

natural disasters or human disturbances

can make sudden changes.

Primary SuccessionOn land, succession that occurs where no soil exists is called primary succession. The first species to populate the area are called pioneer species. Examples) Receding glacier (as glaciers melt, bare rock underneath is exposed) and

volcanic eruptions (new islands or built or land is covered with lava rock).

Lichen is a common pioneer species made up of alga and fungus. Lichen can grow on rock and release acids that help break down the rock into soil. When lichens die,

they leave behind organic material that plants can use to grow.

Secondary succession- Succession that occurs in areas where soil exists, but has been damaged or disturbed. -a change to an existing community that does not affect the soil Example- life after a forest fire

Re-growth after forest fire

Secondary Succession

TankedExamine the fish tank from Finding Nemo. Make a list of Biotic and Abiotic factors seen in the photo.

Study Guide

• Be able to define – Abiotic factor – Succession– Habitat – Biotic Factors – Pioneer Species – Community – Primary Succession – Ecology– Biome – Secondary Succession– Ecosystem – Biosphere

EnergyRecall that all of life’s energy comes from the sun.

Primary productivity- the rate at which producers make energy (from sunlight).

Factors that affect primary productivity include

• Amount of water available to the plant• Amount of sunlight available• Carbon dioxide• Trace elements (nitrogen, potassium)

Producers (AKA autotrophs) - produce energy by capturing sunlight or using chemicals (plants, algae, some bacteria).

Consumers (AKA heterotrophs) - organisms that consume other organisms for food.

Living things can fall into two categories in how they obtain energy:

Most autotrophs obtain energy from the sun through photosynthesis. The energy from sunlight is used to power chemical

reactions to make sugar.

Consumers can be further divided into specific categories-

Herbivore- organism that eats plants Carnivore- eats meatOmnivore- eats both plants + animals

Herbivore Carnivore Omnivore

Detrivores- organisms that obtain their energy from dead matter or waste ( Ex- vultures, crabs, earthworms)

Decomposer- cause decay and release nutrients back into the environment; crucial for the “circle of life” (Ex- bacteria, fungi)

BOB TIME

With a shoulder partner, share what the difference is between a

consumer and a producer.

Homework

• Find three (each) examples of:– Consumer

• Herbivore • Carnivore • Omnivore • Detrivore• Decomposer

– Producer

Shoulder PartnerShare your lists of consumers and producers

Brain Pophttps://www.brainpop.com/science/ecologyandbehavior/foodchains/

Trophic levels- an assigned level in a food chain based on how an organism gets energy; first trophic level always assigned to a producer.

Food chain- the path of energy through the trophic levels (energy flow depicted with arrows)

Energy flows through an ecosystem in one direction, from the sun to autotrophs and then to various heterotrophs.

Typically, there are 4-5 available trophic levels

Food chain= grass → mouse → snake → hawk→ fox (arrows point in direction of energy flow).

Trophic Level Type of Organism ExampleFIRST Producer Sunflower seedsSECOND Primary Consumer MouseTHIRD Secondary Consumer SnakeFOURTH Tertiary Consumer HawkFIFTH Quaternary Consumer Fox

Food web- multiple connected food chains showing the complex interactions within an ecosystem.

There are 10 food chains in this one food web. How many can you find?

Name one primary consumer, one secondary consumer, one tertiary consumer.

Are the any quaternary consumers? (4th level

consumer?)

What does the owl feed on?What does the grasshopper feed on?

When an organism eats another, they are only consuming a small part of the energy that is stored.

This is because so much energy is used for life processes such as movement and reproduction, and some energy is released as body heat.

Seeds are using lots of energy for growth-much

of the energy it has stored has been spent.

Whatever energy the mouse gets from the seeds, it will use up

quickly for movement, growth, etc.

The snake will gain energy from the mouse,

but will again also use the energy it needs for life.

.

Ten-percent-law: only 10% of energy is passed on from trophic level to trophic level. -Energy is typically measured in calories or Joules. (1 kilocalorie [kcal]= 1,000 calories)

Seeds= 10,000 kcal Mouse= 1,000

kcalSnake=100

kcal

How much energy is passed on to each trophic level?TEN PERCENT

Energy pyramid- depicts the ten-percent law. Producers are on the bottom- most of the energy is found at the first trophic level.

As the pyramid moves up through the trophic level, less energy is available. The more levels found between a producer and top-level consumer, the less energy remains.

1,000,000 kcal

100,000 kcal

10,000 kcal

1,000 kcal

Biomass- total amount of living tissue (organic matter) found within a trophic level. Typically measured in grams of organic matter per unit area.

Most of an ecosystem’s dry organic matter is found in the first trophic level (producers). There must be LOTS of producers (algae, plants, etc) in order to support an ecosystem with higher-level carnivores.

A biomass pyramid represents the amount

of potential food available for each

trophic level.

Homework

Food Tracker

Do Now

Identify the food source (plant or animal) from your list from homework

Classwork

• Energy Flow Activity • Food Web Visual Vibe

Homework

• Food Web p. 556 – Using the food web and your notes, identify a

primary and a secondary consumer. Explain your answer.

Classwork

Web Quest :)

Study Guide

• Be able to define – Primary Productivity – Omnivore– Detrivore – Decomposer – Producer– Primary consumer

• Be able to complete a food chain

Biogeochemical CyclesRecall that matter is neither created nor destroyed;

but it can transform and be passed on.Biogeochemical cycles: how water, carbon,

nitrogen and phosphorus pass from the physical environment to living organisms.

BIO GEO CHEMICAL

Life Earth Elements and molecules

There are 3 essential biogeochemical cycles- the water cycle, the carbon cycle, and the nitrogen cycle.

In order for these materials to be recycled, they must change states and transform!

Death and decay also contribute to the biogeochemical cycles. As animals and plants die, bacteria and other decomposers break them down into raw elements, which can be absorbed by plants and then passed on to animals.

Evaporation- liquid water returns to the atmosphere (vaporizes) Transpiration- evaporation of water from plants

The Water CycleAll living things require water to survive. Water moves

between the ocean, atmosphere and the land, cycling from water vapor to liquid water.

Evaporation and transpiration occur during the daytime when the sun heats up the atmosphere.

Water transforming from liquid to

vapor

As the atmosphere cools, the water vapor in the air condenses to form clouds, in a process called condensation.

Precipitation- when the water droplets that form clouds become large enough, the water droplets fall to the earth (rain, sleet, snow).

Once the water is returned to the earth, some of it is absorbed by plants through their roots. Other water continues to seep into the soil to become ground water in a process known as percolation.

Water transforming from vapor to

liquid

Runoff is surface water found on land that is eventually carried back to an ocean or lake.

How is water returned to the earth?How is water returned to the atmosphere?

The Carbon CycleCarbon is an essential element for all living things. Carbon is

found in living tissues, rocks, the atmosphere, and the ocean. Less than 1% of the carbon found on earth participates in the carbon cycle.

Carbon dioxide that is in the air or dissolved in water is used by photosynthesizing plants, algae and bacteria as a raw material to build organic molecules such as glucose.

Carbon may return to the air or water in 3 ways:Respiration- all living organisms undergo cellular respiration.

They use oxygen to break down food; CO2 is a byproduct of the reaction (exhaled).

.

Erosion- marine organisms use carbon to make shells, (calcium carbonate), when they die the calcium carbonate is broken down, CO2 forms and is returned to the atmosphere.

.

Combustion- when carbon returns to the atmosphere through combustion or burning of fossil fuels. (Carbon is locked beneath the earth, dead organisms in sediment may gradually transform by heat and pressure into fossil fuels).

Combustion of fossil fuels releases CO2, which is a greenhouse gas.

• Why do only plants have CO2 going both into and out of them in this diagram?

• Where do fossil fuels come from?

combustion

The Nitrogen CycleNitrogen makes up 78% of the atmosphere, however most

organisms are unable to use it in this form. Bacteria in the soil are very important because they can use atmospheric nitrogen, and fix it into compounds usable by other living things.

Organisms need nitrogen to build proteins and nucleic acids.

Nitrogen fixation- bacteria combine nitrogen from the atmosphere with hydrogen to make ammonia (NH3) in the soil.

Ammonification- production of ammonia by bacteria during the decay of organic matter.

Nitrification- production of nitrates and nitrites from ammonia (NO3). Bacteria are responsible for nitrification. Plants can use nitrates and nitrites to make proteins.

Assimilation- absorption of nitrogen into organic compounds by plants (absorbed through roots).

Denitrification- conversion of nitrate to nitrogen gas, which is released back into the atmosphere.

Rhizobia are a species of bacteria that have a symbiotic

with certain types of plants. They live in their roots and fix

nitrogen into ammonia.

The Nitrogen Cycle

The Phosphorus CyclePhosphorus is necessary to build DNA molecules, as well as RNA. Though phosphorus is necessary, it is not very common in the biosphere and does not enter the atmosphere- it is locked into the land or water.

Phosphorous is found in rocks and minerals in the soil. As these rocks gradually wear down, the phosphorus is released into the soil or water. When organisms die, decomposers in the soil or water break them down into raw elements, including phosphorus, which can then be reused.

When plants absorb phosphate from the soil, it can be passed along from the plants/producers to the other trophic levels.

Nutrient LimitationThe amount of available nutrients directly affects the primary productivity of an ecosystem. -(Primary productivity= rate at which producers produce energy).

Sometimes an ecosystem is limited by a single nutrient that is very scarce or cycles slowly. This is called the limiting nutrient.

Fertilizers are so popular because they contain 3 important nutrients: nitrogen, phosphorus and potassium. By using fertilizers, farmers can ensure that there are enough nutrients and their crops grow to their fullest potential.

How many populations?

The term “population” refers to all the members of one species, in one place at one time.

Population size- the number of individuals in a population

Population density- the number of individuals in a given area

Dispersion- the way individuals are arranged in space

There are three general terms used to describe populations:

Dispersion- How members of a population are arranged in a given space.

What can dispersion tell us about a population?ReproductionProtection (from predators)Hunting Patterns

Individuals in a population may be distributed according to 3 basic patterns of dispersion

– Random– Uniform (aka Even)– Clumped

Random Dispersion- Scattered, not uniform.Why?-Environment is uniform-Individuals are solitary(They live independently).

Pine trees in a random distribution

Uniform Dispersion- About equal distance apart, forming a pattern.Why?

– Resource competition

Clumped Dispersion- Grouped in some places, absent in others. Why?- Resources are patchy- Search for food

Population Density- The number of individuals in a population that live within a given area.

Scientists study density to help determine how the individuals interact.

• Reproduction• Protection• Eating patterns• Social hierarchies, if any

Which population of wildebeest has the greatest population density?

Population GrowthNatural populations tend to stay the same size year after year.

But they can suddenly increase or decrease.

Factors that affect population size: - Number of births- Number of deaths- Number of individuals that enter or leave the population- Immigration: movement of individuals into a population- Emigration: movement of individuals out of a population

Many animals move when they reach maturity to find new territory, mates,

and/or food.

Modeling Population growthPopulation success = reproduction of speciesWe can study how and why the number of individuals change over time. Growth rate of a population (r)(r) = birthrate – death rate

If a population is given abundant resources, protection from predators and disease, then it will thrive.

There are two types of population growth:Exponential Growth

Logistic Growth

Exponential Growth Exponential growth-the rate of population growth stays the same and the population size increases steadily.

This model displays a J-shaped curve which indicates a steady increase of population size.

What if the population size kept growing and growing?

carrying capacity (K)- the population size that an environment can sustain

What factors do you think contribute to an environment's carrying capacity???

Overpopulation can lead to• Insufficient supply of water• Starvation and malnutrition or poor

diet• Unhygienic living conditions. • Higher risk for infectious disease• Disturbance of ecosystems

Density Dependent Factors-Resources that are limited because the rate at which they become depleted depends on the density of the population that uses them.

Examples:

FoodWaterShelter

Can limit the population size!

Logistic GrowthThis model of population growth considers the carrying capacity (K) and is limited by density-dependent factors.

As resources become less available, the growth of a population slows or stops. This forms an S-shaped curve. Population size capped at carrying capacity.

Limiting FactorsA limiting factor is something that causes population growth to decrease.

Density Independent Factors-Factors that do not depend on the size of the population, but can affect it nonetheless.

Examples

WeatherClimate

Can reduce a population size, but it is completely random and does not consider how dense the population is.

r-strategist: Species that grow exponentially when the environment is right. Results in temporarily large populations.

When the environmental conditions are no longer suitable for the species, the population size quickly decreases.

“r” is for rate (as in high rate of population growth)

K- strategists- organisms that grow slowly. Population sizes are usually small and kept near the carrying capacity of their environment.

K-strategists are characterized by a long life span, a slow maturing process, and reproduction late in life.

“K” is for carrying-capacity

What is an ecological community?

Recall that a community is all of the populations that make up an ecosystem.

Describe the community you might find in a tropical rainforest.

CompetitionBecause communities live in the same area, they need to

compete.

When two or more species use the same resources they participate in a biological interaction called competition.

Resources for which species compete may include:

food water shelter mates nesting sites sunlightsoil

Niche

In order to understand how competition influences communities, it is important to understand an organism’s niche.

A niche is the role or function of an organism in its ecosystem.

Example) A jaguar’s niche• Native to South America• Diet- mice, frogs, fish, turtles, caiman, tapir, deer• Reproduction- year round mating, multiple cubs stay with mom for up to 2 years• Time of activity- diurnal

All of the variables that contribute to how an organism affects its ecosystem makes up its niche.

SymbiosisSymbiosis is a close, long-term relationship shared

among species (meaning “living together”).

There are 4 general types of symbiotic relationships: predation, mutualism, parasitism, and commensalism.

Predation- the act of one organism killing another for food.

Example) grizzly bear + salmon

Parasitism- symbiotic relationship in which one individual is harmed but the other is benefitted.

Example) ticks

Mutualism- relationship in which both participating individuals benefit

Example) bees + flowers

Commensalism- one individual benefits; the other is neither helped nor harmed.

Example) clown fish + anemone

Coevolution

What is coevolution? Back and forth evolutionary adjustments between species.

(example: clown fish’s immunity to anemone toxins)

Coevolution can be used to explain some of the symbiotic relationships we see today!

Coevolution produces a balance among communities– no species overpopulates or overpowers

another because they have evolved in such a delicate way.

If an entirely NEW species is introduced to a community, it can disrupt this special balance.

Invasive SpeciesInvasive species are species that are brought to a new

habitat by human means (may be purposeful or accidental i.e., tourism, travel).

Invasive species are considered problematic if they have no population control (no natural predators) in their new habitat, and can thrive in the conditions. They often kill off native species (directly or indirectly) and disrupt the balance found in communities.