Relationships in Ecosystems - Miami-Dade County Public …teachers.dadeschools.net/.../CS212RelationshipsinEcosystems.pdf · Relationships in Ecosystems Big Ideas Diversity and Evolution

Relationships in Ecosystems

Vocabulary


Big Ideas

Diversity and Evolution of Living Organisms Explore the scientific theory of evolution by relating how the inability of a species to adapt within a changing environment may contribute to the extinction of that species. Discuss distinguishing characteristics of the domains and kingdoms of living organisms.


Big IdeasInterdependence Explain and illustrate the roles of and relationships among producers, consumers, and decomposers in the process of energy transfer in a food web. Compare and contrast the relationships among organisms such as mutualism, predation, parasitism, competition, and commensalism. Describe and investigate various limiting factors in the local ecosystem and their impact on native populations, including food, shelter, water, space, disease, parasitism, predation, and nesting sites.


Big Ideas

Interdependence Compare and contrast the relationships among organisms, including predation, parasitism, competition, commensalism, and mutualism. Use a food web to identify and distinguish producers, consumers, and decomposers. Explain the pathway of energy transfer through trophic levels and the reduction of available energy at successive trophic levels.


What is an organism? An individual living thing

What is an environment? The place where an organism lives (its habitat)

What does an organism get from its environment? Food Water Shelter Other things it needs to live, grow and reproduce

What is a niche The role an organism plays in its habitat

NichesOrganisms occupy many niches in an environment.

Interactions Among Living Things


What are the two parts of an organisms’ habitat?Biotic factors Living or once livingExamples: Living organisms, decomposing plant

material, owl pelletsAbiotic factorsNonliving factorsExamples: sunlight, temperature, water


Some abiotic factors Air 78 % nitrogen, 21 % oxygen and .04% carbon dioxide Water is a major ingredient of the fluid inside the cells of all

organisms. Soil is a mixture of mineral and rock particles, the remains of

dead organisms, water, and air. The decaying matter found in soil is called humus.

Sunlight is the energy source for almost all life on Earth. Temperature of a region depends in part on the amount of

sunlight it receives, as well as the latitude and elevation

Climate refers to an area’s average weather conditions over time, including temperature, rainfall or other precipitation, and wind

Wind –motion of air from its heating by the Sun creates air currents that are called wind.

Living Things and the Environment

Factors in a Prairie HabitatA prairie dog interacts with many biotic and abiotic factors in the prairie habitat.


How is an ecosystem organized? Organisms – living things Species – organisms that can mate with each other and

produce offspring that can also mate and reproduce Population – All members of one species in a particular

area Community – All the different populations in a particular

area Ecosystem – All of the communities in a particular area Biosphere – All of the ecosystems on Earth

Draw concentric circles showing the organization of the biosphere

Ecological OrganizationThe smallest level of organization is the organism. The largest is the entire ecosystem.

Living Things and the Environment


What is ecology? The study of how organisms interact with each other and

with their environment

Energy Flow in Living Organisms

A food chain shows a sequence of organisms that eat other organisms.


As you can see, organisms that make their own food are called autotrophs or producers

Organisms that eat other organisms are called heterotrophs or consumers. Three types: Herbivores – eat only producers Omnivores – eat producers and other consumers Carnivores – eat only other consumers

The first heterotroph in a food chain is called the primary consumer, the second, secondary; the third, tertiary

Organisms that break down dead organisms are called decomposers (detrivores)


On a page in your notes, draw a food chain. Include a producer, primary, secondary and tertiary consumers and a decomposer. Remember that decomposers return nutrients to producers


For the purposes of energy flow, a food chain (web) involves the transfer of energy from one organism to another through the cycling of matter (food)


As you move up a food chain, energy is converted when organisms higher up eat organisms lower down.

Some energy is lost during each conversion (Second Law of Thermodynamics); organisms higher in the food chain receive only part of the energy from the organisms they eat.

The energy efficiency of each new level in the food chain is 10% of the level below it.


Because of this loss of energy as organisms eat other organisms, as you move up a food chain, there are fewer and fewer organisms


Energy Flow in Ecosystems Energy Pyramid

Trophic levels Primary

Secondary

Tertiary

Energy PyramidsSuppose that the producers at the base of an energy pyramid contain 330,000 kilocalories. How much energy would be available at each level of the pyramid?

Energy Flow in Ecosystems

Food WebA food web consists of many interconnected food chains.

Energy Flow in Ecosystems


In a food web, lines with arrows are drawn between the organisms being eaten and the organism eating it

The arrow always points from the predator toward the prey, because this is the direction of the energy flow


Common relationships exist between organisms Predator/prey

One organism (predator) eats another (prey) Predator adaptations

Running fast Hunting at night

Prey adaptations Mimicry Camouflage

Predator/prey populations An increase in predators may lead to a decrease in prey, which leads

to a decrease in predators and an increase in prey Adaptations may cause escalation

Faster cheetah selects for faster gembock

Adaptations can cause special relationships to occur between different species

Predator-Prey InteractionsOn Isle Royale, an island in Lake Superior, the populations of wolves (the predator) and moose (the prey) rise and fall in cycles.

Interactions Among Living Things


Common relationships exist between organisms Competition

organisms compete for food or other resources in the same habitat

Adaptations may reduce competitionLiving in different parts of a treeFeeding at different times of day



Symbiotic relationships exist between organismsAt least one organism must benefit Parasitism

Parasites live on (head louse)/in (tapeworm) another animal (host) and feeds on it (parasite benefits at expense of host)

Commensalism animals benefit from each other (hermit crabs with sea anemones on

its shell)

Mutualism animals depend on each other (termites and protozoans that live in

their intestines, coral polyps and zooanthellae)


Populations

Populations change in size Births and deaths

Birth rate – number of births in a certain time period Death rate – number of deaths in a certain time period If birth rate > death rate, population size increases If birth rate < death rate, population size decreases

Growth rate = birth rate – death rate

Populations

Immigration and emigration Immigration – organisms moving into an area Emigration - organisms moving out of an area

Population density Number of individuals / unit area Example: 20 butterflies in a 10 m2 garden 20/10 = 2 butterflies / m2

Immigration/Emigration in a Rabbit PopulationThis graph shows how the size of a rabbit population changed over ten years.

Populations

Population Density of the Flamingos in the PondIn the pond on the top, there are 10 flamingos in 8 square meters. The population density is 1.25 flamingos per square meter.

Populations

Populations

Limiting factor Environmental factor that causes a population to stop growing or

decrease in size Largest population an area can support is its carrying capacity

Factors that limit population growth Food Shelter Water Space Disease Predation and Parasitism Nesting sites

Populations

Factors that limit population growth in the Everglades

Water Flow Pesticides and Herbicides Invasive species (example: Burmese python) Urbanization Water and air quality Food

Classwork 1

1. Name three things an organism gets from its environment

2. ___ factors are living or were once living; ___ factors are non-living

3. Place these in order from smallest to largest:

Population Organisms Ecosystem Community Species

1. Name the type of relationship:a. animals benefit from each other b. animals depend on each other c. organisms compete for food or other resources in same

niched. One organism eats another e. One organism lives on/in another

5. List four factors that limit population growth

Copy the questions into your notebook and answer them

Classwork 1

1. Identify the type of organism

a. break down dead organisms

b. eat only other consumers

c. eat only producers

d. make their own food

e. eat producers and other consumers

2. Part of a food chain: Organism A Organism B

Which is the predator?

1. In a population, the birth rate is less than the death rate. Is the population increasing or decreasing?

2. As you move up a food chain, energy is converted when organisms higher up eat organisms lower down, but the energy efficiency of each new level in the food chain is 10% of the level below it. How does this affect the number of organisms as you move along?


Classwork 1

10. Name three factors that limit populations in the Everglades


Documents

Relationships in Ecosystems - Miami-Dade County Public …teachers.dadeschools.net/.../CS212RelationshipsinEcosystems.pdf · Relationships in Ecosystems Big Ideas Diversity and Evolution